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1.
Foods ; 13(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38890948

RESUMO

Obesity is a global health problem and is increasing in prevalence in most countries. Although obesity affects all age groups, children are the most vulnerable sector. Functional foods are novel formulated foods containing substances (i.e., nutrients, phytochemicals, probiotics, etc.) that have potential health-enhancing or disease-preventing value. The research objective was to study the possible beneficial effects of providing a functional food made with amaranth flour, chia seed, and curcumin extract on the metabolism and behavior of a rat model of childhood obesity. Male Wistar rat pups from two litters of different sizes, a normal litter (NL) (10 pups) and a small litter (SL) (4 pups), were used. After weaning, the rats were fed a hypercaloric diet (HD) or an HD supplemented with the functional food mixture. Body weight and energy intake were measured for seven weeks, and locomotor activity, learning, and memory tests were also performed. At the end of the experiment, glucose and lipid metabolism parameters were determined. The results showed that in this model of obesity produced by early overfeeding and the consumption of a hypercaloric diet, anxiety-like behaviors and metabolic alterations occurred in the rat offspring; however, the provision of the functional food failed to reduce or prevent these alterations, and an exacerbation was even observed in some metabolic indicators. Interestingly, in the NL rats, the provision of the functional food produced some of the expected improvements in health, such as significant decreases in body weight gain and liver cholesterol and non-significant decreases in adipose tissue and leptin and insulin serum levels.

2.
Am J Transl Res ; 14(11): 8292-8314, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36505319

RESUMO

The practice of physical exercise induces a series of physiological changes in the body at different levels, either acutely or chronically. During exercise, the increase in oxygen consumption promotes the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are necessary to maintain homeostasis. ROS/RNS activate cellular signaling pathways, such as the antioxidant cytoprotective systems, inflammation, and cell proliferation, which are crucial for cell survival. However, in exhaustive-extended physical exercise, workloads can exceed the endogenous antioxidant defenses, which may be related to impairment of muscle contraction, fatigue, and a decrease in athletic performance. This review addresses the role of some antioxidants from plant-derived extracts called phytochemicals that can mediate the response to oxidative stress induced by physical exercise by activating signaling pathways, such as Nrf2/Keap1/ARE, responsible for the endogenous antioxidant response and possibly having an impact on sports performance.

3.
Plants (Basel) ; 11(22)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36432781

RESUMO

Bauhinia forficata L. is a tree used in alternative medicine as an anti-diabetic agent, with little scientific information about its pharmacological properties. The hypoglycemic, antioxidant, and genoprotective activities of a methanolic extract of B. forficata leaves and stems combined were investigated in mice treated with streptozotocin (STZ). Secondary metabolites were determined by qualitative phytochemistry. In vitro antioxidant activity was determined by the DPPH method at four concentrations of the extract. The genoprotective activity was evaluated in 3 groups of mice: control, anthracene (10 mg/kg), and anthracene + B. forficata (500 mg/kg) and the presence of micronuclei in peripheral blood was measured for 2 weeks. To determine the hypoglycemic activity, the crude extract was prepared in a suspension and administered (500 mg/kg, i.g.) in previously diabetic mice with STZ (120 mg/kg, i.p.), measuring blood glucose levels every week as well as the animals' body weight for six weeks. The extract showed good antioxidant activity and caused a decrease in the number of micronuclei. The diabetic mice + B. forficata presented hypoglycemic effects in the third week of treatment, perhaps due to its secondary metabolites. Therefore, B. forficata is a candidate for continued use at the ethnomedical level as an adjuvant to allopathic therapy.

4.
J Funct Morphol Kinesiol ; 6(3)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34564191

RESUMO

BACKGROUND: Exercise training induces adaptive physiological and morphological modifications in the entire organism; however, excessive loads of training may increase damage in tissues. The purpose of this study was to evaluate the effect of silymarin in lung and liver histological changes in rats subjected to exercise training (ET). METHODS: Male Wistar rats were subjected to an 8-week ET treadmill program 5 days per week, 60 min/session, and were previously administered 100 mg ascorbic acid or 100 mg of silymarin. RESULTS: Silymarin increased alveolar and bronchial muscle size, improve vascularization, and reduced tissue inflammation. In liver, silymarin promoted the reduction of lipid content. CONCLUSION: Silymarin supplementation may improve inflammation in pulmonary tissue after 8 weeks of the ET treadmill program, improve cell recovery, and reduce intrahepatic lipid content.

5.
Acta Neurobiol Exp (Wars) ; 81(1): 34-42, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33949161

RESUMO

The kappa-opioid system (KOP) is the key in drug abuse. Of all the compounds isolated from Salvia divinorum (S. divinorum), salvinorin-A (Sal-A) is predominant. Further, Sal-A is the only compound within S. divinorum which is reported to have psychoactive properties as a powerful kappa-opioid receptor (KOPr) agonist. Based on the key role of the KOP system in the consumption of drugs, S. divinorum extract (SDE) and Sal-A may modify the alcohol intake in Wistar rats. Assessing voluntary alcohol intake as a drug consummatory behavior, food intake as natural reward behavior and tonic immobility as indicative of anxiety-like behavior, the present study sought to identify the role of both SDE and Sal-A in the Wistar rat model. Forty-eight adult male rats were randomly divided into six groups: control, alcohol naive and vehicle, alcohol-naive and SDE, alcohol-naive and Sal-A, alcohol-consumption and vehicle, alcohol-consumption and SDE, and alcohol-consumption and Sal-A. Alcohol and food intake were assessed for two weeks. In the middle of these two weeks, vehicle, SDE (containing ~1 mg/kg of Sal-A) or Sal-A was injected intraperitoneally once a day for a week. Tonic immobility testing was performed once. The administration of SDE produced a significant increase in voluntary alcohol intake especially in rats with a history of forced alcohol consumption from a juvenile age, Sal-A elicited an increase in alcohol intake in animals with or without previous alcohol exposure, SDE and Sal-A prolonged the tonic immobility duration and decreased food intake. In conclusion, S. divinorum or Sal-A stimulated alcohol consumption in rats with a history of alcohol intake and independent of previous exposure respectively, also SDE or Sal-A elicited an anorexigenic effect, and increased tonic immobility as indicative of anxious-like behavior.The kappa-opioid system (KOP) is the key in drug abuse. Of all the compounds isolated from Salvia divinorum (S. divinorum), salvinorin-A (Sal-A) is predominant. Further, Sal-A is the only compound within S. divinorum which is reported to have psychoactive properties as a powerful kappa-opioid receptor (KOPr) agonist. Based on the key role of the KOP system in the consumption of drugs, S. divinorum extract (SDE) and Sal-A may modify the alcohol intake in Wistar rats. Assessing voluntary alcohol intake as a drug consummatory behavior, food intake as natural reward behavior and tonic immobility as indicative of anxiety-like behavior, the present study sought to identify the role of both SDE and Sal-A in the Wistar rat model. Forty-eight adult male rats were randomly divided into six groups: control, alcohol naive and vehicle, alcohol-naive and SDE, alcohol-naive and Sal-A, alcohol-consumption and vehicle, alcohol-consumption and SDE, and alcohol-consumption and Sal-A. Alcohol and food intake were assessed for two weeks. In the middle of these two weeks, vehicle, SDE (containing ~1 mg/kg of Sal-A) or Sal-A was injected intraperitoneally once a day for a week. Tonic immobility testing was performed once. The administration of SDE produced a significant increase in voluntary alcohol intake especially in rats with a history of forced alcohol consumption from a juvenile age, Sal-A elicited an increase in alcohol intake in animals with or without previous alcohol exposure, SDE and Sal-A prolonged the tonic immobility duration and decreased food intake. In conclusion, S. divinorum or Sal-A stimulated alcohol consumption in rats with a history of alcohol intake and independent of previous exposure respectively, also SDE or Sal-A elicited an anorexigenic effect, and increased tonic immobility as indicative of anxious-like behavior.


Assuntos
Consumo de Bebidas Alcoólicas , Diterpenos Clerodânicos/farmacologia , Ingestão de Alimentos/efeitos dos fármacos , Salvia/metabolismo , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Consumo de Bebidas Alcoólicas/metabolismo , Analgésicos Opioides/metabolismo , Animais , Ansiedade/tratamento farmacológico , Diterpenos Clerodânicos/metabolismo , Etanol/farmacologia , Masculino , Ratos Wistar
6.
Int J Mol Sci ; 21(20)2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33086540

RESUMO

(1) Background: Regular exercise induces physiological and morphological changes in the organisms, but excessive training loads may induce damage and impair recovery or muscle growth. The purpose of the study was to evaluate the impact of Silymarin (SM) consumption on endurance capacity, muscle/cardiac histological changes, bodyweight, and food intake in rats subjected to 60 min of regular exercise training (RET) five days per week. (2) Methods: Male Wistar rats were subjected to an eight-week RET treadmill program and were previously administered SM and vitamin C. Bodyweight and food consumption were measured and registered. The maximal endurance capacity (MEC) test was performed at weeks one and eight. After the last training session, the animals were sacrificed, and samples of quadriceps/gastrocnemius and cardiac tissue were obtained and process for histological analyzes. (3) Results: SM consumption improved muscle recovery, inflammation, and damaged tissue, and promoted hypertrophy, vascularization, and muscle fiber shape/appearance. MEC increased after eight weeks of RET in all trained groups; moreover, the SM-treated group was enhanced more than the group with vitamin C. There were no significant changes in bodyweight and in food and nutrient consumption along the study. (5) Conclusion: SM supplementation may enhance physical performance, recovery, and muscle hypertrophy during the eight-week RET program.


Assuntos
Peso Corporal , Suplementos Nutricionais , Comportamento Alimentar , Músculo Esquelético/patologia , Miocárdio/patologia , Condicionamento Físico Animal , Desempenho Físico Funcional , Silimarina/farmacologia , Animais , Ácido Ascórbico/farmacologia , Peso Corporal/efeitos dos fármacos , Masculino , Músculo Esquelético/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Ratos Wistar , Silimarina/química
7.
Antioxidants (Basel) ; 8(6)2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31242588

RESUMO

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a powerful nuclear transcription factor that coordinates an antioxidant cytoprotector system complex stimulated by the increase in inoxidative stress (OS). In the present manuscript, we conduct a review on the evidence that shows the effect different modalities of physical exercise exert on the antioxidant metabolic response directed by Nrf2. During physical exercise, the reactive oxygen species (ROS) are increased; therefore, if the endogenous and exogenous antioxidant defenses are unable to control the elevation of ROS, the resulting OS triggers the activation of the transcriptional factor Nrf2 to induce the antioxidant response. On a molecular basis related to physical exercise, hormesis maintenance (exercise preconditioning) and adaptative changes in training are supported by a growing body of evidence, which is important for detailing the health benefits that involve greater resistance to environmental aggressions, better tolerance to constant changes, and increasing the regenerative capacity of the cells in such a way that it may be used as a tool to support the prevention or treatment of diseases. This may have clinical implications for future investigations regarding physical exercise in terms of understanding adaptations in high-performance athletes but also as a therapeutic model in several diseases.

8.
Behav Sci (Basel) ; 8(9)2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-30177618

RESUMO

Background: The need to advance and achieve success is deeply ingrained in human evolution. As a species, humans developed instincts that allowed them to survive and transmit their genes along generations. The will to win is an instinct that has been maintained in the species for millions of years. Sport is an activity as old as humans themselves and is subject to rules; Objective: The proposal of this work is to explore some of the most recurrent practices to achieve the athletes' goals, and the origins and historical use of methods or substances to improve performance and its regulation, as well as to review the impact of new technologies on achieving better results and to make a proposal of what actions should be takenin order to prevent bad practices; Methods: A narrative literature review of ethical sports issues and decision-making was performed in the English language; Results: Practically all behavior with regards to the theme of sports is regulated by ethical codes that must be followed by sportspersons, as well as by everyone involved in the athlete's healthcare and in the athlete's administrative, marketing, and business aspects. Notwithstanding this, winning and reaping glory implies a reward far greater than fame and fortune, which can lead to poor ethical practices in athletes, as well as in interested parties who detract from the intrinsic value of the spirit of sports. The will to win could exceed the limits of what is permitted in fair-play, like the use of prohibited methods or substances; Conclusions: In this work, we review some of the bioethical aspects ofsports. Additionally, recommendations are offered for good practices and to prevent falling into poor ethical behavior.

9.
World J Hepatol ; 10(2): 297-307, 2018 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-29527265

RESUMO

AIM: To examine the association between weekend alcohol consumption and the biochemical and histological alterations at two different concentrations of alcohol in both genders in rats. METHODS: Wistar rats weighing 170-200 g were divided into groups as follows: (1) Control groups; and (2) weekend alcohol-consumption group: 2 d/weekly per 12 wk, at two different concentrations: (1) Group of males or females with a consumption of a solution of alcohol at 40%; and (2) group of males or females with a consumption of a solution of alcohol at 5%. At the end of the experiment, serum and liver samples were obtained. The following enzymes and metabolites were determined in serum: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Lactate Dehydrogenase, and Gamma-Glutamyltransferase, and glucose, triglycerides, cholesterol, bilirubin, and albumin. Liver samples from each group were employed to analyze morphological abnormalities by light microscopy. RESULTS: In all of the weekend alcohol-consumption groups, AST activity presented a significant, 10-fold rise. Regarding ALT activity, the groups with weekend alcohol consumption presented a significant increase that was six times greater. Bilirubin levels increased significantly in both groups of females. We observed a significant increase in the parameters of fatty change and inflammation due to weekend alcohol consumption. Only the group of females that consumed alcohol at 40% presented slight hepatocellular disorganization. CONCLUSION: The results obtained herein provide solid evidence that weekend alcohol consumption gives rise to liver damage, demonstrated by biochemical and histological alterations, first manifested acutely, and prolonged weekend alcohol consumption can cause greater, irreversible damage.

10.
Int J Clin Exp Pathol ; 10(7): 7801-7811, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31966628

RESUMO

The objective was to determine the regulatory dynamic of Nrf2 during liver regeneration and the administration of EtOH and/or the G. schiedeanum extract. Male Wistar rats weighing 200-230 g were subjected to a 70% partial hepatectomy; they were then divided into three groups (groups 1-3). During the experiment, animals in Group 1 drank only water. The other two groups (2-3) received an intragastric dose of ethanol (1.5 g/kg BW, solution at 40% in isotonic saline solution). Additionally, rats in group 3 received a geranium extract daily at a dose of 300 mg/kg BW i.g. EtOh and/or Geranium schiedeanum was administered to rats with regenerating livers for 7 days. At the end of treatment, the activity was determined of the antioxidant enzymes, DNA concentration, TBARS, and TAC, in addition to the expression of Nrf-2, Cyclin D1, and Nqo1. EtOH increased ROS and Nrf-2, which activated the antioxidant defenses and delayed liver proliferation. On the other hand, Geranium schiedeanum exerted an antioxidant effect, diminishing ROS, but Nrf-2 expression increased, favoring liver proliferation through the increase of DNA concentration and the overexpression of Cyclin D1, however it did not activate the antioxidant defenses. In sum, it can be concluded that Nrf-2 possesses a regulatory dynamic that is evident in the presence of a toxic agent (EtOH) and/or a phytochemical agent with antioxidant capacity (Geranium schiedeanum) during liver regeneration.

11.
Molecules ; 17(4): 4435-51, 2012 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-22499190

RESUMO

There are few reports that demonstrate the antigenotoxic potential of cranberries. Although the types of berry fruits consumed worldwide are many, this paper focuses on cranberries that are commonly consumed in Mexico (Vaccinium macrocarpon species). The purpose of the present study is to determine whether cranberry ethanolic extract (CEE) can prevent the DNA damage produced by benzo[a]pyrene (B[a]P) using an in vivo mouse peripheral blood micronucleus assay. The experimental groups were organized as follows: a negative control group (without treatment), a positive group treated with B[a]P (200 mg/kg), a group administered with 800 mg/kg of CEE, and three groups treated with B[a]P and CEE (200, 400, and 800 mg/kg) respectively. The CEE and benzo[a]pyrene were administered orally for a week, on a daily basis. During this period the body weight, the feed intake, and the determination of antigenotoxic potential were quantified. At the end of this period, we continued with the same determinations for one week more (recovery period) but anymore administration of the substances. The animals treated with B[a]P showed a weight increase after the first week of administration. The same phenomenon was observed in the lots combined with B[a]P and CEE (low and medium doses). The dose of 800 mg/kg of CEE showed similar values to the control group at the end of the treatment period. In the second part of the assay, when the substances were not administered, these experimental groups regained their normal weight. The dose of CEE (800 mg/kg) was not genotoxic nor cytotoxic. On the contrary, the B[a]P increases the frequency of micronucleated normochromatic erythrocytes (MNNE) and reduces the rate of polychromatic erythrocytes (PE) at the end of the treatment period. With respect to the combined lots, a significant decrease in the MN rate was observed from the sixth to the eighth day of treatment with the two high doses applied; the highest protection (60%) was obtained with 800 mg/kg of CEE. The same dose showed an anticytotoxic effect which corresponded to an improvement of 62.5% in relation to the animals administered with the B[a]P. In the second period, all groups reached values that have been seen in the control group animals. Our results suggest that the inhibition of clastogenicity of the cranberry ethanolic extract against B[a]P is related to the antioxidant capacity of the combination of phytochemicals present in its chemical composition.


Assuntos
Benzo(a)pireno/toxicidade , Dano ao DNA/efeitos dos fármacos , Extratos Vegetais/farmacologia , Vaccinium macrocarpon/química , Animais , Antioxidantes/farmacologia , Relação Dose-Resposta a Droga , Masculino , Camundongos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Testes para Micronúcleos
12.
Neuro Endocrinol Lett ; 33(7): 703-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23391881

RESUMO

OBJECTIVES: We evaluated the contribution of the thyroid hormones to the long-term maintenance of feeding behavior and body weight, while distinguishing their direct central effects from those resulting from the metabolic rate in the peripheral tissues. METHODS: We assessed the effect of hypothyroidism on the long-term (6 months) regulation of food intake, body weight, and energy expenditure in rats. We then generated the recovery of a euthyroid condition in the brain while maintaining a low T3 availability for the peripheral organs, i.e. a combined condition of central euthyroidism with peripheral hypothyroidism, with the aid of a pharmacological combination. RESULTS: Hypothyroidism caused a decrease in the daily food intake, body weight, and body temperature. The food intake and body temperature stabilized at a lower value, whereas body weight kept decreasing at a constant rate. The administration of exogenous T4 increased food intake and body-weight gain, but had no effect on body temperature. CONCLUSIONS: The thyroid hormones are necessary for the long-term regulation of energy intake, storage, and expenditure by different mechanisms. The feeding behavior seems to be partially dependent on a direct action of the thyroid hormones on the brain and this effect is independent of the energy expenditure in the peripheral organs. The body weight is closely dependent on the thyroid status and its maintenance seems to involve thyroid action on mechanisms other than feeding and metabolic rate.


Assuntos
Peso Corporal/fisiologia , Química Encefálica/fisiologia , Ingestão de Alimentos/fisiologia , Hipotireoidismo/fisiopatologia , Tiroxina/sangue , Tri-Iodotironina/sangue , Animais , Antitireóideos/farmacologia , Temperatura Corporal/efeitos dos fármacos , Temperatura Corporal/fisiologia , Peso Corporal/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/fisiologia , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/tratamento farmacológico , Masculino , Metimazol/farmacologia , Ratos , Ratos Wistar , Tiroxina/farmacologia , Fatores de Tempo
13.
Molecules ; 16(10): 8319-31, 2011 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-21959302

RESUMO

It is well known that gadolinium chloride (GD) attenuates drug-induced hepatotoxicity by selectively inactivating Kupffer cells. In the present study the effect of GD in reference to cell cycle and postnecrotic liver regeneration induced by thioacetamide (TA) in rats was studied. Two months male rats, intraveously pretreated with a single dose of GD (0.1 mmol/Kg), were intraperitoneally injected with TA (6.6 mmol/Kg). Samples of blood and liver were obtained from rats at 0, 12, 24, 48, 72 and 96 h following TA intoxication. Parameters related to liver damage were determined in blood. In order to evaluate the mechanisms involved in the post-necrotic regenerative state, the levels of cyclin D and cyclin E as well as protein p27 and Proliferating Cell Nuclear Antigen (PCNA) were determined in liver extracts because of their roles in the control of cell cycle check-points. The results showed that GD significantly reduced the extent of necrosis. Noticeable changes were detected in the levels of cyclin D1, cyclin E, p27 and PCNA when compared to those induced by thioacetamide. Thus GD pre-treatment reduced TA-induced liver injury and accelerated the postnecrotic liver regeneration. These results demonstrate that Kupffer cells are involved in TA-induced liver and also in the postnecrotic proliferative liver states.


Assuntos
Ciclo Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Gadolínio/farmacologia , Células de Kupffer/efeitos dos fármacos , Células de Kupffer/metabolismo , Regeneração Hepática/efeitos dos fármacos , Animais , Pontos de Checagem do Ciclo Celular , Proliferação de Células/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Ciclina D/sangue , Ciclina E/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Necrose/tratamento farmacológico , Antígeno Nuclear de Célula em Proliferação/sangue , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Wistar , Tioacetamida/toxicidade
14.
Molecules ; 16(8): 6927-49, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21844842

RESUMO

After 6 months of operation a long-term biofilter was stopped for two weeks and then it was started up again for a second experimental period of almost 1.3 years, with high toluene loads and submitted to several physical and chemical treatments in order to remove excess biomass that could affect the reactor's performance due to clogging, whose main effect is a high pressure drop. Elimination capacity and removal efficiency were determined after each treatment. The methods applied were: filling with water and draining, backwashing, and air sparging. Different flows and temperatures (20, 30, 45 and 60 °C) were applied, either with distilled water or with different chemicals in aqueous solutions. Treatments with chemicals caused a decrease of the biofilter performance, requiring periods of 1 to 2 weeks to recover previous values. The results indicate that air sparging with pure distilled water as well as with solutions of NaOH (0.01% w/v) and NaOCl (0.01% w/v) were the treatments that removed more biomass, working either at 20, 30 or 45 °C and at relatively low flow rates (below 320 L h(-1)), but with a high biodegradation inhibition after the treatments. Dry biomass (g VS) content was determined at three different heights of the biofilter in order to carry out each experiment under the same conditions. The same amount of dry biomass when applying a treatment was established so it could be considered that the biofilm conditions were identical. Wet biomass was used as a control of the biofilter's water content during treatments. Several batch assays were performed to support and quantify the observed inhibitory effects of the different chemicals and temperatures applied.


Assuntos
Poluição do Ar/prevenção & controle , Biodegradação Ambiental , Biotecnologia/métodos , Filtração/métodos , Biomassa , Reatores Biológicos , Biotecnologia/instrumentação , Destilação , Filtração/instrumentação , Concentração de Íons de Hidrogênio , Cinética , Consórcios Microbianos , Pressão , Hidróxido de Sódio/química , Hipoclorito de Sódio/química , Temperatura , Tolueno/química , Tolueno/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Água
15.
Horm Behav ; 50(1): 27-32, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16473354

RESUMO

In nature, many species under conditions of stress (e.g., predator attack, pups carried by the mother, mating) show immobility states called "immobility responses" (IRs), which are characterized by the complete absence of movement and a relative unresponsiveness. These IR states can be induced by several kinds of sensorial stimuli. Many brain neurotransmitters from diverse cerebral areas participate in the expression of IRs. Other factors are also involved in IRs, such as learning and hormones, but at present, there is not enough experimental support about these factors. Our purpose was to investigate whether the IRs are subject to sexual hormone modulation and to examine the possible relation to learning processes. We tested the effects of acute testosterone decanoate (30 mg/kg, s.c.) and repetitive induction of two IRs; cataleptic immobility (CAT) and dorsal immobility (DI). These were tested in mice of both sexes which were either gonadectomized or sham-treated. CAT and DI were measured before and then 1 and 5 h after testosterone injection. The results show a differential effect of the repetitive induction on CAT and DI. CAT was augmented with repetition, and DI was decreased. Sex differences of the effects of the acute testosterone treatment were observed. Sham and castrated male mice showed CAT potentiation; in contrast, DI was reduced albeit only in sham male mice. Sham and ovariectomized female mice were not affected by testosterone. These results support the hypothesis that there are multiple immobility systems that can be differentially modulated by brain regions associated with processes of learning.


Assuntos
Aprendizagem por Associação/fisiologia , Reação de Congelamento Cataléptica/fisiologia , Resposta de Imobilidade Tônica/fisiologia , Reconhecimento Psicológico/fisiologia , Testosterona/fisiologia , Análise de Variância , Animais , Feminino , Habituação Psicofisiológica/fisiologia , Masculino , Camundongos , Fatores Sexuais
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