Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 6.906
Filter
1.
Braz. j. biol ; 84: e250936, 2024. graf
Article in English | LILACS, VETINDEX | ID: biblio-1345557

ABSTRACT

Abstract This study was carried out to evaluate the effect of Glutamine, as a dipeptide or a free amino acid form, on the progression of burn injuries in rats. Thirty male Wistar rats were burned with a comb metal plate heated in boiling water (98 °C) for three minutes, creating four rectangular full-thickness burn areas separated by three unburned interspaces (zone of stasis) in both dorsum sides. The animals were randomized into three groups (n=10): saline solution (G1-Control) and treated groups that orally received Glutamine as dipeptide (G2-Dip) or free amino acid (G3-FreeAA). Two and seven days after burn injury, lesions were photographed for unburned interspaces necrosis evolution assessment. Seven days after injury, glutathione seric was measured and histopathological analysis was performed. By photographs, there was a significant reduction in necrosis progression in G3-Free-AA between days two and seven. Histopathological analysis at day 7 showed a significantly higher stasis zone without necrosis and a higher number of fibroblasts in G2-Dip and G3-FreeAA compared with G1-Control. Also, glutathione serum dosage was higher in G2-Dip. The plasmatic glutathione levels were higher in the G2-Dip than the G1-Control, and there was a trend to higher levels in G3-FreeAA. The reduction in histological lesions, greater production of fibroblasts, and greater amounts of glutathione may have benefited the evolution of burn necrosis, which showed greater preservation of interspaces.


Resumo Este estudo foi realizado para avaliar o efeito da Glutamina, como um dipeptídeo ou forma de aminoácido livre, na progressão de queimaduras em ratos. Trinta ratos Wistar machos foram queimados com um pente de metal aquecido em água fervente (98 °C) por três minutos, criando quatro áreas retangulares queimadas separadas por três interesespaços não queimados (zona de estase) em ambos os lados do dorso. Os animais foram randomizados em três grupos (n = 10): solução salina (G1-Controle) e grupos tratados que receberam glutamina via oral como dipeptídeo (G2-Dip) ou aminoácido livre (G3-FreeAA). Dois e sete dias após a queimadura, as lesões foram fotografadas para avaliação da evolução da necrose entre os espaços não queimados. Sete dias após a lesão, foi dosada a glutationa sérica e realizada análise histopatológica. Pelas fotografias, houve uma redução significativa na progressão da necrose no G3-Free-AA entre os dias dois e sete. A análise histopatológica no dia 7 mostrou uma zona de estase significativamente maior sem necrose e número mais elevado de fibroblastos em G2-Dip e G3-FreeAA em comparação com G1-Controle. Os níveis plasmáticos de glutationa foram maiores no G2-Dip em relação ao G1-Controle, e houve tendência a níveis mais elevados no G3-FreeAA. A redução das lesões histológicas, maior produção de fibroblastos, maior quantidade de glutationa podem ter beneficiado a evolução da necrose da queimadura, que mostrou maior preservação dos interespaços.


Subject(s)
Animals , Male , Rats , Burns/drug therapy , Glutamine , Rats, Wistar , Dipeptides , Disease Models, Animal , Amino Acids
2.
Braz. j. biol ; 83: e237412, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1355854

ABSTRACT

Abstract Only few studies have focus on animals that received Pilocarpine (Pilo) and did not develop behavioral status epilepticus (SE) and, whether they may become epileptic in the model's chronic phase. Previews works observed mossy fiber sprouting in the hippocampus of Non-SE (NSE) rats, while others observed spontaneous and recurrent seizures (SRS) 6 - 8 months after animals received Pilo. It is known that neuronal excitability is influenced by female hormones, as well as, the occurrence of SE in castrated and non-castrated female rats. However, it is not known whether females that received Pilo and did not show SE, may have SRS. The aim of this work was to investigate whether castrated and non-castrated female rats that did not show behavioral SE after Pilo, will develop SRS in the following one-year. For that, animals received 360 mg/kg of Pilo and were video monitored for 12 months. SE females from castrated and non-castrated groups became epileptic since the first month after drug injection. Epileptic behaviors were identified watching video monitoring recordings in the fast speed. Castrated and Non-castrated NSE animals showed behaviors resembling seizures described by Racine Scale stages 1 - 3. Motor alterations showed by NSE groups could be observed only when recordings were analyzed in slow speed. In addition, behavioral manifestations as, rhythmic head movements, sudden head movements, whole body movements and immobility were also observed in both, SE and NSE groups. We concluded that NSE female rats may have become epileptic. Adding to it, slow speed analysis of motor alterations was essential for the observation of NSE findings, which suggests that possibly many motor alterations have been underestimated in epilepsy experimental research.


Resumo Poucos são os estudos com foco em animais que receberam Pilocarpina (Pilo) e não desenvolveram status epilepticus (SE) comportamental e, se os mesmos se tornarão epilépticos na fase crônica do modelo. Autores observaram o brotamento das fibras musgosas no hipocampo de ratos Não-SE (NSE), enquanto outros observaram crises espontâneas e recorrentes (CER) 6 - 8 meses após receberam a droga. A excitabilidade neuronal é influenciada pelos hormônios femininos e, da mesma forma, a ocorrência de SE em ratas castradas e não-castradas. Entretanto, não é sabido se as fêmeas que não apresentam SE terão CER. O objetivo deste trabalho foi investigar se fêmeas castradas e não castradas que não tiveram SE comportamental após a injeção de Pilo desenvolverão CER dentro de um ano. Para isto, os animais receberam 360 mg/kg de Pilo e foram videomonitorados por 12 meses. As fêmeas SE castradas e não-castradas se tornaram epilépticas desde o primeiro mês pós Pilo. O comportamento epiléptico foi identificado assistindo as gravações na velocidade rápida. As fêmeas NSE castradas e não-castradas apresentaram comportamentos similares aos estágios 1 - 3 da Escala de Racine. As alterações motoras nestes grupos (NSE) foram observadas apenas quando as videomonitoração foi analisada na velocidade lenta. Além destas, manifestações comportamentais como movimentos rítmicos da cabeça, movimentos súbitos da cabeça, movimentos de todo o corpo e imobilidade também foram observadas em ambos grupos, SE e NSE. Concluímos que as fêmeas NE podem ter se tornado epilépticas. Adicionado a isto, a análise das alterações motoras na velocidade lenta foi essencial para a observação dos achados das fêmeas NSE, o que sugere que possivelmente muitas alterações motoras têm sido subestimados na pesquisa em epilepsia experimental.


Subject(s)
Animals , Female , Rats , Pilocarpine/toxicity , Seizures/chemically induced , Status Epilepticus/chemically induced , Rats, Wistar , Muscarinic Agonists/toxicity , Models, Theoretical
3.
Braz. j. biol ; 83: e248032, 2023. graf
Article in English | LILACS, VETINDEX | ID: biblio-1278557

ABSTRACT

Abstract A new species of nematode parasite of the subfamily Pudicinae (Heligmosomoidea: Heligmonellidae) is described from the small intestine of Proechimys simonsi (Rodentia: Echimyidae) from the locality of Nova Cintra in the municpality of Rodrigues Alves, Acre state, Brazil. The genus Pudica includes 15 species parasites of Neotropical rodents of the families Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae, and Myocastoridae. Four species of this nematode were found parasitizing three different species rodents of the genus Proechimys in the Amazon biome. Pudica wandiquei n. sp. can be differentiated from all other Pudica species by the distance between the ends of rays 6 and 8 and the 1-3-1 pattern of the caudal bursa in both lobes.


Resumo Uma nova espécie de nematódeo da subfamília Pudicinae (Heligmosomoidea: Heligmonellidae) é descrito parasitando o intestino delgado de Proechimys simonsi (Rodentia: Echimyidae) em Nova Cintra, município de Rodrigues Alves, Estado do Acre, Brasil. O gênero Pudica inclui 15 espécies parasitas de roedores Neotropicais das famílias: Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae e Myocastoridae. Destas, quatro espécies de nematódeos foram encontradas parasitando três diferentes espécies do roedor Proechimys no bioma Amazônia. Pudica wandiquei n. sp. é diferente das outras espécies de Pudica pela distância entre os raios 6 e 8 e pelo tipo da bolsa caudal, que é 1-3-1 em ambos os lados.


Subject(s)
Animals , Parasites , Trichostrongyloidea , Nematoda , Rodentia , Brazil
4.
Arq. bras. cardiol ; 119(2): 294-304, ago. 2022. graf
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-1383745

ABSTRACT

Resumo Fundamento: A (-)-carvona é um monoterpeno encontrado em óleos essenciais com atividade antioxidante e anti-inflamátoria. Objetivos: O objetivo deste estudo foi analisar a propriedade antiarrítmica da (-)-carvona no coração de rato e seus efeitos sobre a sinalização de Ca+2 intracelular. Métodos: Os efeitos da (-)-carvona foram avaliados sobre a contratilidade atrial (0,01 - 4 mM) e ventricular (0,5 mM), e no eletrocardiograma (0,5mM). A fração de encurtamento, a corrente de cálcio do tipo L (ICa,L) e a sinalização de Ca+2 foram medidas no cardiomiócito isolado (0,5 mM). O efeito antiarrítmico foi avaliado no modelo de arritmia induzida por sobrecarga de cálcio (0,5 mM) (n = 5). Um p < 0,05 foi adotado como nível de significância estatística. Resultados: No átrio, a (-)-carvona causou inotropismo negativo de maneira concentração-dependente (EC50 0,44 ± 0,11 mM) e diminuiu o inotropismo positivo induzido pelo CaCl2 (0,1 - 8,0 mM) e BAY K8644 (5 - 500 nM), um agonista de canal de cálcio do tipo L. Em coração isolado, a (-)-carvona (0,5mM) reduziu a contratilidade ventricular em 73% e a frequência cardíaca (em 46%), aumentou o Pri (30,7%, tempo desde o início da onda P até a onda R) e o QTc (9,2%, uma medida de despolarização e repolarização dos ventrículos), sem mudar a duração do complexo QRS. A (-)-carvona diminuiu a fração de encurtamento (61%), a (ICa,L) (79%) e o transiente intracelular de Ca+2 (38%). Além disso, a (-)-carvona apresentou ação antiarrítmica, identificada pela redução do escore de arritmia (85%) e ocorrência de fibrilação ventricular. Conclusão: A (-)-carvona reduz a entrada de Ca+2 através de canais de Ca+2 do tipo L e, assim, diminui a contratilidade cardíaca e o Ca+2 intracelular e apresenta promissora atividade antiarrítmica no coração de ratos.


Abstract Background: (-)-Carvone is a monoterpene found in essential oils with antioxidant and anti-inflammatory activity. Objective: The aim of this paper was to analyze the antiarrhythmic property of (-)-carvone in the rat heart and its effects on the intracellular Ca2+ signaling. Methods: The effects of (-)-carvone were evaluated on the ventricular (0.5 mM) and atrial contractility (0.01 - 4 mM) and on electrocardiogram (0.5 mM). Fractional shortening, L-type calcium current (ICa,L) and Ca2+ signaling were measured in the isolated cardiomyocyte (0.5 mM). Antiarrhythmic effect was evaluated in arrhythmia model induced by calcium overload (0.5 mM) (n = 5). P < 0.05 was used as the significance level. Results: In the atrium, (-)-carvone evoked negative inotropism that was concentration-dependent (EC50 0.44 ± 0.11 mM) and decreased the positive inotropism evoked by CaCl2 (0.1 to 8.0 mM) or BAY K8644 (5 to 500 nM), an agonist of L-type Ca2+ channel. In isolated heart, (-)-carvone (0.5 mM) promoted reduction of ventricular contractility (73%) and heart rate (46%), increased PRi (30.7%, time from the onset of the P wave until the R wave) and QTc (9.2%, a measure of the depolarization and repolarization of the ventricles) without changing the QRS complex duration. (-)-Carvone decreased the fractional shortening (61%), ICa,L (79%) and Ca2+ intracellular transient (38%). Furthermore, (-)-carvone showed antiarrhythmic action, verified by decrease of the arrhythmia score (85%) and occurrence of ventricular fibrillation. Conclusion: (-)-Carvone decreases Ca2+ entry through L-type Ca2+ channels, reducing the cardiac contractility and intracellular Ca2+, and, therefore, presenting promising antiarrhythmic activity in the rat hearts.

5.
Rev. bras. cir. cardiovasc ; 37(4): 447-453, Jul.-Aug. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1394729

ABSTRACT

Abstract Introduction: This study's objective is to investigate the effect of downregulation of micro ribonucleic acid (miR)-124a on myocardial injury after ischemia reperfusion (I/R) in rats. Methods: Sprague Dawley (SD) rats (n=20) were divided into four groups - sham, I/R, I/R+miR-124a antagomir (I/R+ant-miR-124a), and I/R+ant-normal control (NC). The pathomorphological and infarct size variance of injured myocardial tissues with IR were conducted with hematoxylin (HE) and triphenyltetrazolium chloride (TTC) staining. The expression levels of miR-124a, BAX, nuclear factor kappa B (NF-KB), Notch1, and Hes1 were examined by quantitative real-time polymerase chain reaction or Western blot in myocardium. The inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α) were detected by the enzyme-linked immunosorbent assay, as well as the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum by colorimetry. Results: The expression of miR-124a was increased in the I/R group. Compared with I/R and I/R+ant-NC groups, after downregulating miR-124a, the expression of IL-6, IL-1β, TNF-α, BAX, NF-KB, LDH, and CK were decreased, but the expression of Notch1 and Hes1 were increased. In HE staining, myocardial tissue edema, red blood cell exudation, and myocardial fiber arrangement disorder were accompanied by inflammatory cell infiltration and local necrosis in the I/R group. However, the pathological injury of myocardial tissue was alleviated after downregulating miR-124a. Additionally, TTC results showed that the myocardial infarction area was decreased in the I/R+ant-miR-124a group. Conclusion: Downregulation of miR-124a expression through Notch pathway can significantly reduce myocardial damage after 24 hours of I/R in SD rats. Therefore, miR-124a may become a potential therapeutic target for I/R injury.

6.
Int. j. cardiovasc. sci. (Impr.) ; 35(4): 459-464, July-Aug. 2022. tab
Article in English | LILACS | ID: biblio-1385263

ABSTRACT

Abstract Background: Hyperthyroidism (Hy) is an endocrine disorder, in which the thyroid hormones markedly alter the cardiac function. Increased myocardial contractility and cardiac output, improvement in diastolic relaxation, changes in electrical activity, increments in ventricular mass, and arrhythmias have been reported. However, the influences of thyroid hormones upon molecular mechanisms of cardiac functions have not yet been fully understood. Objectives: To evaluate changes in cardiac contractile parameters and the Na+/Ca2+ exchanger (NCX) function in induced hyperthyroid rats. Methods: Hy was induced by intraperitoneal injections of T3 (15 μg/100 g) for 10 days. Contractile parameters and NCX function were evaluated in the isolated papillary muscle. Data normality was confirmed by the Shapiro-Wilk test. The comparison between groups was performed through an unpaired Student's t-test. Results are expressed as mean ± SD. The accepted significance level was p < 0.05. Results: Our data revealed, in the Hy group, an increase of 30.98% in the maximum speed of diastolic relaxation (-284.64 ± 70.70 vs. -217.31 ± 40.30 mN/mm2/sec (p = 0.027)) and a boost of 149% in the NCX function in late phase of relaxation (20.17 ± 7.90 vs. 50.22 ± 11.94 minutes (p = 0.002)), with no changes in the maximum twitch force (p = 0.605) or maximum speed of systolic contraction (p = 0.208) when compared to the control. Conclusion: The improvement in relaxation parameters is hypothetically attributed to an increase in Sarco-Endoplasmic Reticulum Ca2+ATPase isoform 2 (SERCA2) expression and an increased calcium flow through L-type channels that boosted the NCX function.


Subject(s)
Animals , Male , Rats , Papillary Muscles/physiology , Sodium-Calcium Exchanger/physiology , Hyperthyroidism/complications , Thyroid Hormones , Intervention Studies , Rats, Wistar
8.
Rev. bras. ortop ; 57(2): 267-272, Mar.-Apr. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1387984

ABSTRACT

Abstract Objective To verify how the combined administration of alendronate (ALN) and vitamin D3 (VD) acts on the bone microarchitecture in rats with glucocorticoid-induced osteoporosis. Methods The experiment used 32 90-day-old female Wistar rats weighing between 300 and 400g. The induction of osteoporosis consisted of intramuscular administration of dexamethasone at a dose of 7.5 mg/kg of body weight once a week for 5 weeks, except for the animals in the control group. The animals were separated into the following groups: G1 (control group without osteoporosis), G2 (control group with osteoporosis without treatment), G3 (group with osteoporosis treated with ALN 0.2 mg/kg), G4 (group with osteoporosis treated with VD 10,000UI/500μL), and G5 (group with osteoporosis treated with ALN þ VD). The right femurs of the rats were fixed in 10% buffered formaldehyde, decalcified, and processed for inclusion in paraffin. Histological sections were stained with hematoxylin-eosin for histomorphometric analysis. Cortical thickness and medullary cavity were measured in cross-sections. Results There was a statistical difference (p< 0.05) between groups G3 and G5 compared with the positive control group (G2), both related to the measurement of cortical thickness and to the total diameter of the bone. In the evaluation of the spinal area, only the G3 group has shown to be statistically different from the G2 group. Conclusion Concomitant treatment with daily ALN and weekly VD is effective in preventing glucocorticoid-induced bone loss. However, there was no difference between the therapy tested and treatment with ALN alone.


Resumo Objetivo Verificar como a administração conjunta de alendronato de sódio (ALN) e vitamina D3 (VD) atua na microarquitetura óssea em ratas com osteoporose induzida por glicocorticoide. Métodos O experimento utilizou 32 ratas da linhagem Wistar, com peso médio de 300 a 400g, com 90 dias de vida. A indução da osteoporose consistiu na administração de dexametasona na dose de 7,5 mg/kg de peso corporal, por via intramuscular, 1 vez por semana durante 5 semanas, à exceção dos animais do grupo controle. Os animais foram distribuídos nos seguintes grupos: G1 (grupo controle sem osteoporose), G2 (grupo controle com osteoporose sem tratamento), G3 (grupo com osteoporose tratado com ALN 0,2 mg/kg), G4 (grupo com osteoporose tratado com VD 10.000UI/500μL) e G5 (grupo com osteoporose tratado com ALN þ VD). Os fêmures direitos das ratas foram fixados em formol a 10% tamponado, descalcificados e processados para inclusão em parafina. Os cortes histológicos foram corados com hematoxilina-eosina para análise histomorfométrica. A espessura cortical e a cavidade medular foram medidas em cortes transversais. Resultados Houve diferença estatística (p< 0,05) entre os grupos G3 e G5 em relação ao grupo controle positivo (G2), tanto em relação à medida da espessura cortical quanto em relação ao diâmetro total do osso. Na avaliação da área medular, apenas o grupo G3 se mostrou estatisticamente diferente do grupo G2. Conclusão O tratamento concomitante com ALN diário e VD semanal é eficaz para prevenir a perda óssea induzida por glicocorticoide. No entanto, não houve diferença entre esta terapia testada e o tratamento apenas com o ALN.

9.
Int. j. cardiovasc. sci. (Impr.) ; 35(2): 214-219, Mar.-Apr. 2022. tab
Article in English | LILACS | ID: biblio-1364976

ABSTRACT

Abstract Background Various studies are ongoing related to the radioprotective agents. Herbal preparations are currently becoming popular because of their beneficial effects with fewer side effects compared to the synthetic/semi-synthetic medicines, and Nigella sativa oil (NSO) is only one of them. Objective To investigate NSO for its antioxidant effects on the heart tissue of rats exposed to ionizing radiation (IR). Methods Thirty six male albino Wistar rats, divided into four groups, were designated to group I (IR plus NSO group) that received both 5 Gray of gamma IR to total cranium and NSO; group II (IR alone group) that received IR plus saline, group III (control group of NSO) that received saline and did not receive NSO or IR; group IV (control group) that received only sham IR. Alterations in Total antioxidant status (TAS) and Total oxidant status (TOS), Oxidative stres index (OSI), Sulhydryl group (SH), Lipid hydroperoxide (LOOH), Paraoxonase (PON) levels, Arylesterase (ARE) and Ceruloplasmin (CER) activities in homogenized heart tissue of rats were measured by biochemical methods. Results In heart tissue of the rats in the IR alone group (group II) LOOH, TOS and OSI levels were found to be higher, ARE activity and TAS level were found to be lower than all of the other groups (p < 0.01). These results also support that IR increases oxidative stress and NSO's protective effect. Conclusion NSO would reduce the oxidative damage in the irradiated heart tissue in the experimental rat model.


Subject(s)
Animals , Male , Rats , Radiation-Protective Agents/therapeutic use , Plant Oils/therapeutic use , Nigella sativa , Oxidative Stress/drug effects , Heart/radiation effects , Antioxidants/therapeutic use , Plants, Medicinal , Radiation-Protective Agents/analysis , Rats, Inbred Strains , Rats, Wistar , Oxidative Stress/radiation effects , Plant Preparations/therapeutic use , Cardiotoxicity/drug therapy , Heart/drug effects , Phytotherapy
10.
Biomédica (Bogotá) ; 42(1): 196-206, ene.-mar. 2022. graf
Article in Spanish | LILACS | ID: biblio-1374518

ABSTRACT

Introducción. Las lesiones del nervio facial afectan la plasticidad a largo plazo en el hipocampo, así como la memoria de reconocimiento de objetos y la memoria espacial, dos procesos dependientes de esta estructura. Si bien se ha descrito una activación de la microglía en la corteza motora primaria asociada con esta lesión, no se conoce si ocurre algo similar en el hipocampo. Objetivo. Caracterizar en ratas el efecto de la lesión unilateral del nervio facial sobre la activación de células de la microglía en el hipocampo contralateral. Materiales y métodos. Se hicieron experimentos de inmunohistoquímica para detectar células de la microglía en el hipocampo de ratas sometidas a lesión irreversible del nervio facial. Los animales se sacrificaron en distintos momentos después de la lesión, para evaluar la evolución de la proliferación (densidad de células) y la activación (área celular) de la microglía en el tejido del hipocampo. Los tejidos cerebrales de los animales de control se compararon con los de animales lesionados sacrificados en los días 1,3, 7, 21 y 35 después de la lesión. Resultados. Las células de la microglía en el hipocampo de animales con lesión del nervio facial mostraron signos de proliferación y activación a los 3, 7 y 21 días después de la lesión. Sin embargo, al cabo de cinco semanas, estas modificaciones se revirtieron, a pesar de que no hubo recuperación funcional de la parálisis facial. Conclusiones. La lesión irreversible del nervio facial produce proliferación y activación temprana y transitoria de las células de la microglía en el hipocampo. Estos cambios podrían estar asociados con las modificaciones electrofisiológicas y las alteraciones comportamentales dependientes del hipocampo descritas recientemente.


Introduction: Facial nerve injury induces changes in hippocampal long-term synaptic plasticity and affects both object recognition memory and spatial memory consolidation (i.e., hippocampus-dependent tasks). Although facial nerve injury-associated microglíal activation has been described regarding the primary motor cortex, it has not been ascertained whether something similar occurs in the hippocampus. Peripheral nerve injury- associated microglíal changes in hippocampal tissue could explain neuronal changes in the contralateral hippocampus. Objective: To characterize the effect of unilateral facial nerve injury on microglíal proliferation and activation in the contralateral hippocampus. Materials and methods: Immunohistochemical experiments detected microglíal cells in the hippocampal tissue of rats that had undergone facial nerve injury. The animals were sacrificed at specific times after injury to evaluate hippocampal microglíal cell proliferation (cell density) and activation (cell area); sham-operated animals were compared to lesioned animals sacrificed 1,3, 7, 21, or 35 days after injury. Results: Facial nerve-injured rats' hippocampal microglíal cells proliferated and adopted an activated phenotype 3- to 21-days post-lesion. Such modifications were transient since the microglíal cells returned to their resting state five weeks after injury, despite the injury's irreversible nature. Conclusions: Facial nerve injury causes the transient proliferation and activation of microglíal cells in the hippocampus. This finding might partly explain the morphological and electrophysiological changes described for CA1 pyramidal neurons and the impairment of spatial memory consolidation which has previously been observed in facial nerve-injured rats.


Subject(s)
Facial Nerve , Hippocampus , Rats , Immunohistochemistry
12.
Braz. j. otorhinolaryngol. (Impr.) ; 88(1): 28-35, Jan.-Feb. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1364575

ABSTRACT

Abstract Introduction Considering that previous studies suggest that pesticides may cause hearing disorders in humans, as well as the lack of studies proving the specific mechanisms of injury and the difficulty of separating concomitant etiological factors of the hearing damage, such as noise and vibration, it is important to develop studies using animal models to elucidate the effects of exposure to those substances isolated from other hearing damage etiologies. Objective To evaluate if the exposure to a dichlorvos based organophosphorus insecticide may induce ototoxicity. Methods 36 male Wistar rats were assigned to 3 groups (12 rats/group): control (exposed to water), positive control (treated with cisplatin to induce hearing damage) and experimental (exposed to dichlorvos based organophosphorus insecticide). The amplitude of distortion product otoacoustic emissions in the frequencies of 4, 6, 8, 10 and 12 kHz was evaluated before and after exposure, as well as systemic toxicity signs, body mass gain and plasma cholinesterase. Open field and plus maze tests were performed in 24 rats: experimental (n = 8), control (n = 8) and positive control group (n = 8 introduced new rats to induce anxiolytic activity) to evaluate the locomotor activity and anxiety, respectively. Results There was no significant change in body mass gain and plasma cholinesterase in the dichlorvos based organophosphorus insecticide group, however, the animals showed transient piloerection, depression and dyspnea during exposure. The behavior was not affected in any group. The frequencies of 8 and 10 kHz were significantly affected bilaterally in the insecticide group, which also showed a significant difference of the control in 10 kHz on the right and 8 and 10 kHz on the left ear. Conclusion Subchronic inhalation exposure to dichlorvos based organophosphorus insecticide induced ototoxicity in the cochlear function of rats without relevant systemic toxicity.


Resumo Introdução Considerando que estudos anteriores sugerem que pesticidas podem causar distúrbios auditivos em humanos, além da falta de estudos que comprovem os mecanismos específicos de lesão e a dificuldade em separar fatores etiológicos concomitantes dos danos auditivos, como ruído e vibração, é importante desenvolver estudos que usem modelos animais para elucidar os efeitos da exposição a substâncias isoladas de outras etiologias de danos auditivos. Objetivo Avaliar se a exposição a um inseticida organofosforado baseado em diclorvos pode induzir ototoxicidade. Método Foram divididos em 3 grupos 36 ratos Wistar machos (12 ratos/grupo): controle (exposto à água), controle positivo (tratado com cisplatina para induzir dano auditivo) e experimental (exposto ao inseticida). A amplitude das emissões otoacústicas por produto de distorção nas frequências de 4, 6, 8, 10 e 12 kHz foi avaliada antes e após a exposição, bem como sinais de toxicidade sistêmica, ganho de massa corporal e colinesterase plasmática. Os testes Open Field e Plus Maze foram feitos em 24 ratos: experimental (n = 8), controle (n = 8) e grupo controle positivo (n = 8, introduziu novos ratos para induzir atividade ansiolítica) para avaliar a atividade locomotora e a ansiedade, respectivamente. Resultados Não houve alteração significativa no ganho de massa corporal e colinesterase plasmática no grupo experimental; entretanto, os animais apresentaram piloereção transitória, depressão e dispneia durante a exposição. O comportamento não foi afetado em qualquer grupo. As frequências de 8 e 10 kHz foram significativamente afetadas bilateralmente no grupo exposto ao inseticida, o qual também mostrou uma diferença significativa do controle em 10 kHz na orelha direita e 8 e 10 kHz na orelha esquerda. Conclusão A exposição subcrônica inalatória de inseticida organofosforado baseado em diclorvos induziu ototoxicidade na função coclear de ratos sem toxicidade sistêmica relevante.

13.
An. Fac. Med. (Perú) ; 83(1): 12-18, ene.-mar. 2022. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1374217

ABSTRACT

RESUMEN Objetivo. Demostrar cual es el resultado de la protección del aceite de Sacha inchi (SI) al realizar una inducción artificial de artritis al inyectar carragenina a ratas Holtzman. Métodos. Estudio cuantitativo, experimental y correlacional; se usaron 30 ratas macho: divididos en cinco grupos aleatorios : 1) Solución salina fisiológica (SSF) 2 mL/kg; 2) Carragenina (C) 0,1 mL solución 2% vía intraarticular, en la zona de la articulación del fémur con la tibia izquierda; 3) C y SI 250 mg/kg; 4) C y SI 1125 mg/kg; y 5) C y SI 2250 mg/ kg; determinándose tiempo (segundos), tipo de prensión (normal, pobre, regular, moderada, intensa), e inflamación pannus, fibrosis pannus, mediante estudio histopatológico. Se aplicó análisis de varianza, y los test de Tukey y Fisher. Resultados. Hubo mayor porcentaje de efecto antiinflamatorio dosis dependiente y tiempo de prensión a 2250 mg/Kg, seguido por 1125 mg/Kg. El estudio histopatológico mostró un pannus leve y fibrosis ausente con la dosis más alta; a dosis de 1125 mg/Kg de aceite SI hubo pannus moderado, y fibrosis leve. Conclusiones. Se demostró el resultado protector del aceite de Sacha Inchi (SI) aumentando y mejorando el tiempo tipo de prensión y reducción del pannus en la artritis inducida por carragenina en ratas Holtzman.


ABSTRACT Objective. To demonstrate the protective effect of Sacha inchi oil (SI) in arthritis induced by carrageenan in Holtzman rats. Methods. Quantitative, experimental and correlational study; 30 rats, males, randomly distributed in 5 groups were used: 1) SSF 2 mL/kg; 2) Carrageenan; 3) 4) and 5) Sacha inchi. Except for the control, they received 0.1 mL 2% carrageenan intra-articularly (the area of the femur joint with the left tibia); sacha inchi oil orally 225, 1125 and 2250 mg/kg correspondingly; determining time (seconds), type of grip (normal, poor, regular, moderate, intense), and pannus inflammation, pannus fibrosis by means of histopathological study. Applying analysis of variance, Tukey and Fisher test. Results. There was a higher percentage of dose-dependent anti-inflammatory effect and grasp time at 2250 mg/Kg, followed by 1125 mg/Kg; and the histopathological study showed mild pannus and absent fibrosis with the highest dose, in contrast to doses of 1125 mg/Kg of oil there was moderate pannus, and mild fibrosis. Conclusions. The protective effect of Sacha inchi oil (SI) has demonstrated by increasing the time and improving the type of grasp and reducing the pannus in arthritis induced by carrageenan in Holtzman rats.

14.
Acta sci., Health sci ; 44: e58558, Jan. 14, 2022.
Article in English | LILACS | ID: biblio-1367771

ABSTRACT

Cardiovascular disease(CVD) remains the major cause of mortality in the world, typically claiming a third of all deaths. The primary cause of CVD is atherosclerosis. Therefore, timely prevention and therapy of atherosclerosis are able to reduce the risk of the development of its clinical manifestations. Anti-atherosclerotic activity of medicinal plants mainly appears in their multiple effects.This study was carried out to evaluate the hypolipidemic activity of virgin olive oil in experimentally induced hyperlipemic Wistar. A total of 24 rats were randomly allocated to 4 equal groups and treated as follows for 50 days: (1) Normal control (NC); that were fed with a standart diet; (2) High Cholesterol Diet Control (HCD); which received high cholesterol diet for 50 days; (3) Animals receiving high cholesterol diet for 50 days, after this period the animals are fed for eight days by the standard foodand receiving by gavage virgin olive oil (HCD+VOO) and(4) Animals fed for eight days with the standard food and receiving by gavage olive oil (VOO). High Cholesterol Diet containing yolk egg and coconut oil. Results showed that olive oil caused a significant (p < 0.01) reduction in serum levels of Total Cholesterol (TC), Triglycerides (TG), Low­Density Lipoprotein Cholesterol (LDL) and Atherogenic Index Serum (AIS). The results also demonstrated a significant (p < 0.01) increase in High­Density Lipoprotein Cholesterol (HDL). Moreover, virgin olive oil induced a significant reduction in liver lipid content. On the other hand, a High cholesterol diet induced oxidative stress was measured by estimating reduced glutathione level and amount of thiobarbituric acid reactive substances (TBARS) formed as an index of lipid peroxidation in a liver and a heart. Virgin olive oil supplementation attenuated all these variations. Our observations of the study indicate that the virgin olive oil has a significant antihyperlipidemic potential.


Subject(s)
Animals , Rats , Oxidative Stress/immunology , Atherosclerosis/diet therapy , Diet, High-Fat/methods , Olive Oil/pharmacology , Triglycerides/pharmacology , Lipid Peroxidation/immunology , Cholesterol/pharmacology , Rats, Wistar/immunology , Diet, Atherogenic/methods , Glutathione/pharmacology , Hypercholesterolemia/immunology , Lipoproteins/immunology
15.
Braz. oral res. (Online) ; 36: e024, 2022. tab, graf
Article in English | LILACS-Express | LILACS, BBO | ID: biblio-1360251

ABSTRACT

Abstract: The aim of this study was to use microscopic and molecular techniques to evaluate the effects of a single session of antimicrobial photodynamic therapy (aPDT) on the alveolar repair process after tooth extraction in rats. The study sample included 84 rats divided into four groups, as follows: a) Control - untreated socket; b) Laser - socket treated using photobiomodulation; c) TBO - socket treated with topic application of the photosensitizer agent, toluidine blue O (TBO); and d) aPDT - socket treated with TBO and laser irradiation. An additional rat was used for thermal mapping during socket irradiation. The animals were euthanatized at 6, 15, and 28 days after unilateral extraction of the upper incisor. Quantitative and qualitative analyses of the connective and bone tissues, blood clot, blood vessel, and inflammatory infiltrate were performed, and real-time polymerase chain reaction was used to study the expression of genes (collagen type I, osteocalcin, alkaline phosphatase [ALP], runt-related transcription factor 2 [RUNX2], and vascular endothelial growth factor [VEGF]) involved in the bone healing process. No statistically significant differences in microscopic and molecular outcomes were observed between the groups (p > 0.05). A positive correlation was seen to exist between blood clot and VEGF (p = 0.000), and a negative correlation was observed between bone tissue and ALP (p = 0.028) and blood vessel and VEGF (p = 0.018). A single session of aPDT in the dental extraction site did not influence the alveolar repair process in rats.

16.
Acta ortop. bras ; 30(2): e191015, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1374142

ABSTRACT

ABSTRACT Objective: To evaluate histological changes in peripheral nerves of rats after sciatic nerve neurorrhaphy, according to the time of exposure to hyperbaric oxygen chamber treatment. Methods: Twenty-five Wistar rats were divided into 5 groups according to the amount of exposure to hyperbaric oxygen chamber treatment. Group 1 was the control and there was no use of hyperbaric oxygen chamber; group 2 received one week of therapy; group 3, two weeks; group 4, three weeks; and group 5, four weeks. After the fourth postoperative week, the animals were submitted to euthanasia and a sciatic nerve sample sent for histological analysis. Axons proximal and distal to the neurorrhaphy were counted with axonal regeneration index measurement. Results: We observed that the number of axons distal to neurorrhaphy increases with the amount of hyperbaric oxygen chamber exposure, the results were more expressive from the third week of treatment. However, the statistical analysis found no significant difference between the groups. Conclusion: The descriptive analysis suggests benefit of using hyperbaric oxygen chamber directly proportional to the time of therapy. The study, however, did not present statistically relevant results, probably due to the reduced sample size. Subsequent studies with more significant sampling would be of great value. Level of Evidence II, Prospective Comparative Study.


RESUMO Objetivo: Avaliar as alterações histológicas nos nervos periféricos após neurorrafia do nervo ciático de ratos, de acordo com o tempo de exposição ao tratamento com câmara hiperbárica de oxigênio. Métodos: Vinte e cinco ratos da raça Wistar foram divididos em cinco grupos conforme o tempo de exposição ao tratamento com câmara hiperbárica de oxigênio. O grupo 1 não recebeu o tratamento; o grupo 2 recebeu uma semana de terapia; o grupo 3, duas semanas; o grupo 4, três semanas; e o grupo 5, quatro semanas. Após quatro semanas de pós-operatório, os animais foram submetidos à eutanásia e uma amostra do nervo ciático foi enviada para análise histológica. Foram feitas contagens do número de axônios proximalmente e distalmente à neurorrafia, com medição do índice de regeneração axonal. Resultados: Observamos que o aumento do número de axônios distais à neurorrafia foi diretamente proporcional ao tempo de exposição à câmara hiperbárica de oxigênio, sendo mais expressivo a partir da terceira semana de tratamento. Entretanto, a análise estatística não encontrou diferença significativa entre os grupos. Conclusão: A análise descritiva sugere benefício do uso da câmara hiperbárica de oxigênio. Porém, devido à amostra reduzida, o estudo não apresentou resultados estatisticamente relevantes, sendo necessária a realização de estudos subsequentes com amostragem mais significativa. Nível de Evidência II, Estudo Prospectivo Comparativo.

17.
Einstein (Säo Paulo) ; 20: eAO5587, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1375356

ABSTRACT

ABSTRACT Objective: To evaluate the effects of combining topiramate, bupropion and naltrexone in obesity-induced rats on their weight and subcutaneous adipose tissue. Methods: A total of 40 male Wistar rats were induced to obesity for 8 weeks and the animals were divided into 8 groups: Ctr - control, G0 - Sham, G1 - oral saline solution (1.0mL/day), G2 - topiramate (20.0mg/kg) and bupropion (5.0mg/kg), G3 - naltrexone (20.0mg/kg), G4 - topiramate (20.0mg/kg), G5 - bupropion (5.0mg/kg) and G6 - topiramate (20.0mg/kg), bupropion (5.0mg/kg) and naltrexone (20.0mg/kg). During the experiment, all animals were weighed weekly. After 30 days of treatment animals were euthanized and their skin fragments were processed and stained with hematoxylin and eosin for morphological, morphometric and biochemical analyzes. Results: The only group that presented a decrease in the volume of subcutaneous adipose tissue was G3, but this decrease was not significant when compared with the other groups. The G4, the G5 and the G6 presented increased adipose tissue volume. Data showed that until the eighth week all animals increased their weight by approximately 50%. After treatment animals of all groups, except G3, increased their weight from 4% to 9% approximately. The G3 was the only group that lost weight, but this decrease was not significant. Conclusion: The medicines studied were not efficient in reducing weight in obese rats. However, it should be considered that 30-day treatment period is not enough to observe the stronger effects of these drugs.

18.
ABCD arq. bras. cir. dig ; 35: e1662, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1383214

ABSTRACT

ABSTRACT - BACKGROUND: Although many methods have been defined for colonic anastomosis, anastomotic leak still remains important for sepsis control and successful healing. AIM: The purpose of this study was to compare the effects of conventional suture, polyglactin 910 mesh, and omental flap coverage on healing and anastomotic leak in experimental colonic anastomosis in rats. METHOD: This study was conducted on 18 Wistar rats and the animals were divided into three groups as follows: Group 1: primary suture group; Group 2: primary suture plus polyglactin 910 mesh group; and Group 3: primary suture plus omental flap coverage group. Groups were compared in terms of anastomotic bursting pressure, inflammation, fibroblastic activity, neovascularization, and collagen amount. RESULTS: There was a statistically significant difference in anastomotic bursting pressure between Groups 1 and 2 and between Groups 1 and 3 (p=0.004, p<0.05). There was a significant difference in fibroblastic activity between Groups 1 and 3 (p=0.011, p<0.05) and between Groups 2 and 3 (p=0.030, p<0.05). There was a significant difference in neovascularization and collagen between Groups 1 and 2 and between Groups 1 and 3 (p<0.05). CONCLUSION: This experimental study found that polyglactin 910 mesh and omental flap coverage for colocolic anastomoses improved the physical strength and healing of the anastomosis compared to conventional hand-stitched anastomoses. The polyglactin may be a safe alternative to 910 mesh in cases where the omental flap coverage cannot be used in the colonic anastomosis.


RESUMO - RACIONAL: Embora muitos métodos tenham sido definidos para anastomose colônica, a fistula anastomótica ainda permanece importante para o controle da sepse e a cura bem-sucedida. OBJETIVO: comparar os efeitos da sutura convencional, tela de poliglactina 910 e cobertura de retalho omental na cicatrização e extravasamento anastomótico em anastomose colônica experimental em ratos. MÉTODO: estudo realizado em 18 ratos Wistar, sendo os animais divididos em 3 grupos. Grupo 1: Grupo de sutura primária; Grupo 2: sutura primária com malha de poliglactina 910; Grupo 3: Grupo sutura primária com cobertura de retalho omental. Os grupos foram comparados em termos de pressão de ruptura anastomótica, inflamação, atividade fibroblástica, neovascularização e quantidade de colágeno. RESULTADOS: houve diferença estatisticamente significativa na pressão de ruptura da anastomose entre os Grupos 1 e 2 e os Grupos 1 e 3 (p=0,004, p<0.05). Houve uma diferença significativa na atividade fibroblástica entre os Grupos 1 e 3 (p=0,011, p<0.05) e os Grupos 2 e 3 (p=0,030, p<0.05). Houve uma diferença significativa na neovascularização e colágeno entre os Grupos 1 e 2 e entre os Grupos 1 e 3 (p<0,05, p<0.05). CONCLUSÃO: o estudo experimental demonstrou que a tela de poliglactina 910 e a cobertura do retalho omental para anastomoses colocólicas melhoraram a resistência física e a cicatrização da anastomose em comparação com as anastomoses suturadas manualmente convencionais. A poliglactina pode ser uma alternativa segura à tela 910 nos casos em que a cobertura do retalho omental não pode ser utilizada na anastomose colônica.

19.
Braz. oral res. (Online) ; 36: e084, 2022. tab, graf
Article in English | LILACS-Express | LILACS, BBO | ID: biblio-1384206

ABSTRACT

Abstract This study aimed to evaluate the potential of strontium ranelate (SR) in medication-related jaw osteonecrosis (MRONJ) after tooth extraction in ovariectomized rats. Thirty ovariectomized rats were divided into three groups (n = 10): bisphophonate (BP) group (zoledronic acid; 0.4 mg/kg/week), SR group (625 mg/kg/day), and control group (saline solution). The lower first molars were extracted after 60 days of drug therapy. Drug administration was continued for another 30 days after tooth extraction. The mandibles were subjected to clinical, histological, radiographic, and microtomographic evaluations. Only the BP group showed clinical changes, characterized by the presence of 70% (n = 7) and 20% (n = 2) of ulcers and extraoral fistulas. Radiographic evaluation demonstrated bone sequestration only in the BP group (n = 7, 70%). Microtomographic analysis revealed increased bone porosity after ovariectomy, particularly in the the control group (p < 0.05). The BP group showed a higher bone surface density, bone volume, and trabecular number than SR and control groups, but with less trabecular separation (p < 0.05). All the animals in the BP group demonstrated histological osteonecrosis. There was no evidence of osteonecrosis in the control and SR groups, which was characterized by the absence of empty osteocyte gaps and associated with the gradual healing of the extraction area. Also, an increased number of blood vessels and a reduced number of osteoclasts were observed in the SR group (p < 0.05). Therefore, SR treatment increased angiogenesis and osteoclastogenesis in the healing socket and was not associated with MRONJ development after tooth extraction in ovariectomized rats.

SELECTION OF CITATIONS
SEARCH DETAIL