Effects of low molecular weight heparin on alveolar bone loss in wistar rats

Abstract This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes.

Resumo O presente estudo objetivou verificar o efeito da heparina de baixo peso molecular (HBPM) sob a perda óssea alveolar (POA), contagem de células sanguíneas, megacariócitos e adipócitos em ratos Wistar machos. Quarenta ratos Wistar de 60 dias foram randomicamente divididos em quatro grupo: Controle (C), Doença Periodontal (DP), Heparina (Hp) e Heparina + Doença Periodontal (Hp+DP). HBPM foi aplicada durante 60 dias em doses de 1 mL/kg/dia. Coletas sanguíneas foram realizadas nos dias 0, 30 e 60. No dia 49, os grupos DP e Hp+DP receberam indução de doença periodontal por ligadura ao redor do segundo molar superior direito. No lado esquerdo, verificou-se perda óssea alveolar espontânea. A média de POA no lado com ligadura mostrou-se estatisticamente diferente entre os grupos C (0,35±0,07 mm) e Hp+PD (0,49±0,09 mm) (p<0,001), entre os grupos DP (0,55±0,11 mm) e Hp (0,32±0,06 mm) (p<0,001) e entre os grupos Hp e Hp+DP (p<0,001). Nenhuma diferente significativa foi observada entre os grupos no lado sem ligadura. Peso dos animais, consumo de ração e ingestão de água não mostraram diferenças significativas entre os grupos. Megacariócitos e adipócitos foram contados por microscopia óptica e nenhuma diferença significativa foi encontrada. Dentro dos grupos, houve um aumento e uma diminuição, respectivamente, na contagem de linfócitos (p=0,005 no grupo C e p=0,009 no grupo Hp+DP somente) e leucócitos (p=0,003 no grupo C, p=0.001 no grupo DP e p=0,002 no grupo Hp e Hp+DP). Não houve diminuição no número de plaquetas nos três períodos de coleta. HBPM não foi capaz de modificar a POA, porém modificou a contagem de células sanguíneas, especialmente aumentando o número de linfócitos.

Comparative Study for Preventive Effects of Intra-Abdominal Adhesion Using Cyclo-Oxygenase-2 Enzyme (COX-2) Inhibitor, Low Molecular Weight Heparin (LMWH), and Synthetic Barrier

PURPOSE: Postoperative adhesion is the most frequent complication of abdominal surgery. Therefore, we investigated the individual effects of synthetic barrier [hyaluronic acid/carboxymethylcellulose (HA/CMC)] and pharmacologic agents [low molecular weight heparin (LMWH) cyclo-oxygenase-2 inhibitor (COX-2 inhibitor)] using animal model of intra-abdominal adhesion. MATERIALS AND METHODS: The cecum was rubbed with sterile alcohol wet gauze until subserosal haemorrhage and punctate bleeding developed under the general anesthesia. Five animal groups were prepared using the film HA/CMC, gel HA/CMC, LMWH and COX-2 inhibitor. RESULTS: The grade of adhesion by modified Leach method for group I (control), II (film type HA/CMC), III (gel type HA/CMC), IV (LMWH) and V (COX-2 inhibitor) were 5.35+/-1.8, 6.15+/-1.3, 4.23+/-2.6, 5.05+/-0.7 and 5.50+/-0.9, respectively. Group III showed the least grade of adhesion and it is statistically significant in adhesion formation (p=0.028). The numbers of lymphocytes were significantly low in group III and group V compared to the control group (lymphocyte: p=0.004). The mast cell counts were generally low except for the control group (I: 1.05, II: 0.35, III: 0.38, IV: 0.20, V: 0.37), however, it was not statistically significant (p=0.066). CONCLUSION: The gel barriers were shown to be partly efficient in inhibiting the formation of postoperative adhesions and might provide an option for abdominal surgery to reduce postoperative adhesions. The LMWH and COX-2 inhibitor had been known for their inhibitor effect of fibrin formation and anti-angiogenic/anti-fibroblastic activity, respectively. However, their preventive effects of adhesion and fibrosis were found to be obscure.

Comparison of effects of unfractionated heparin and low molecular weight heparin on skin wound healing of rats / Comparação dos efeitos da heparina não fracionada e heparina de baixo peso molecular na cicatrização de feridas na pele de ratos

PURPOSE: To compare the effects of unfractionated heparin (UH) and a low molecular weight heparin (LMWH) on skin wound healing of rats. METHODS: Forty eight male Sprague-Dawley rats underwent 8mm full thickness dorsal skin wounds and were randomly assigned to three equal groups. In experimental group A, heparin sodium was injected at a concentration of 1000U/kg. In experimental group B, enoxaparin was injected at a concentration of 1mg/kg. Physiologic saline (0.5ml) was administered to the control group. Injections were made subcutaneously, once daily, for seven days. At 7th and 10th days tissue samples were taken from all rats. Histologic examination of these tissues was made under light microscope and scored. RESULTS: Histological examination showed a significant difference between the 7th and 10th day groups in wound healing. It was observed that wound healing of LMWH injected group is better. This difference is statistically significant at 10th day. CONCLUSIONS: Daily administration of single doses of unfractionated heparin and a low molecular weight heparin improves wound healing positively. Low molecular weight heparin induces wound healing more than unfractionated heparin.

OBJETIVO: Comparar os efeitos da heparina não fracionada (HNF) e da heparina de baixo peso molecular (HBPM) na cicatrização de feridas cutâneas de ratos. MÉTODOS: Quarenta e oito ratos machos Sprague-Dawley foram submetidos à ferida na pele dorsal com espessura total de 8mm e foram distribuídos aleatoriamente em três grupos iguais. No grupo experimental A, a heparina sódica foi injetada a uma concentração de 1000U/kg. No grupo experimental B, a enoxaparina foi injetada a uma concentração de 1mg/kg. Solução salina fisiológica (0,5ml) foi administrada para o grupo controle. As injeções foram feitas por via subcutânea, uma vez por dia, durante sete dias. Nos dias 7º e 10º amostras de tecido foram obtidas de todos os ratos. O exame histológico destes tecidos foi realizado em microscópio de luz. RESULTADOS: O exame histológico mostrou uma diferença significativa entre os grupos no 7º e 10º dias na cicatrização das feridas. Observou-se que a cicatrização de feridas do grupo com heparina de baixo peso molecular foi melhor. Esta diferença foi estatisticamente significante no 10º dia. CONCLUSÕES: A administração diária de doses únicas de heparina não fracionada e de heparina de baixo peso molecular melhora a cicatrização de feridas. A heparina de baixo peso molecular induz melhor a cicatrização de feridas do que a heparina não fracionada.

Evaluation of the efficacy of aspirin and low molecular weight heparin in patients with unexplained recurrent spontaneous abortions

The roles of inflammatory cytokines and local placental thrombosis in patients with unexplained recurrent spontaneous abortion [URSA] have been shown. Since low molecular weight heparin [LMWH] and acetyl salicylic acid [ASA] have both anti-inflammatory and anti-coagulant effect, we evaluated their efficacy in patients with URSA. One hundred patients with a history of URSA referring to Obstetrics Clinic affiliated to Shiraz University of Medical Sciences between 2004 and 2009 were randomly divided into two groups. Fifty patients in thromboprophylaxis group were treated with LMWH [5000 unit; twice a day], ASA [80 mg daily] and calcium supplement [500 mg daily] after detection of fetal heart beat. Another 50 patients received no thromboprophylaxis. Live birth rate, obstetrical complications, prenatal and neonatal complications and hemorrhagic side effects were recorded. Both groups were matched for mean age and mean number of pervious abortions. Thromboprophylaxis group had a higher rate of live birth [83.7%] in comparison to the control group [54%]. No maternal or neonatal side effects were seen. There were no differences in obstetrical complications, prenatal and neonatal complications between the two groups. Thromboprophylaxis with ASA and LMWH seems to be safe and effective in patients with URSA

Protective Effect of Ultra Low Molecular Weight Heparin on Glutamate-Induced Apoptosis in Cortical Cells

PURPOSE: To investigate the effect of ultra low molecular weight heparin (ULMWH) on glutamate induced apoptosis in rat cortical cells and to explore the possible mechanisms. MATERIALS AND METHODS: Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was first analyzed with Hoechst 33258 and then confirmed by DNA fragmentation. The concentration of free intracellular calcium ([Ca2+](i)) was determined with fura-2/AM fluorometry. The expression of Bcl-2 family protein and caspase-3 were evaluated with Western blot. RESULTS: Typical apoptotic morphological change in rat cortical cells treated with 100micromol/L glutamate for 24h was detected by Hoechst 33258 staining, which was then confirmed by the DNA ladder of agarose gel electrophoresis. The apoptotic rate of the glutamate treated cells was up to 33.21%, and 24 h of treatment with glutamate increased [Ca2+](i), down-regulated Bcl-2 expression, up-regulated Bax expression, and increased caspase-3 activation in rat cortical cells. Our research demonstrated that ULMWH pretreatment can prevent the glutamate- induced apoptosis, attenuate the increase of [Ca2+](i) not only in medium containing Ca2+ but also in Ca2+-free medium, up-regulate the expression of Bcl-2, down-regulate the expression of Bax, and decrease caspase-3 activation. CONCLUSION: ULMWH has neuroprotective capacity to antagonize glutamate-induced apoptosis in cortical cells, through decrease of Ca2+ release and modulation of apoptotic processes.

Estudo experimental dos efeitos da heparina de baixo peso molecular (Enoxaparina) na formacao de calo ósseo em fêmures de ratos / The effects of low-molecular-weight heparin (Enoxaparin) on bony callus formation in rats' femurs - an experimental study

O tromboembolismo venoso é uma complicacao grave que pode ocorrer após fraturas. O tratamento anticoagulante mais utilizado é com a heparina de baixo peso molecular (HBPM). Existem estudos que mostram que essa droga pode interferir no metabolismo ósseo. Com o objetivo de avaliar a influência da HBPM no processo de formacao de calo ósseo, realizamos um estudo experimental em ratos. A amostra constituiu-se de 22 ratos de linhagem Wistar, machos, que foram submetidos à fratura diafisária de seus fêmures direitos. Foram divididos em dois grupos de 11. No grupo controle, os animais recebiam soro fisiológico e no grupo de estudo, recebiam HBPM, enoxaparina, diariamente, por 28 dias. Após este período os ratos foram submetidos à eutanásia e os fêmures foram avaliados. No estudo macroscópico foi constatada consolidacao em 11 animais (100 por cento) que nao receberam enoxaparina, e, em dez animais (90,9 por cento) que receberam a droga em estudo. No estudo histológico foi constatada a formacao de calo ósseo em todos os fêmures. Concluiu-se neste experimento que a enoxaparina nao altera o processo de consolidacao óssea em fêmures de ratos Wistar.

Efeito da heparina sódica e da enoxaparina na consolidação de fratura da tíbia no rato: avaliação clínica e anatomopatológica e biomecânica / Effect of heparin-sodium and enoxaparin on rats tibial fracture healing: clinical,anatomopathological, and biomechanical approach

Foi realizado estudo experimental em ratos para avaliar o efeito do anticoagulante na consolidação óssea, conforme critérios clínicos, anatomopatológicos e biomecânicos. Manualmente, após perfuração do osso, foi produzida fratura aberta, na diáfise da tíbia direita, mantida sem imobilização, em 72 ratos machos da linhagem Wistar, com 60 dias de idade e peso médio de 242 gramas. Doze horas após a fratura, foi iniciado tratamento anticoagulante, mantido por 28 dias. Via subcutânea, um grupo recebeu heparina sódica na dose de 200UI/Kg de 12 em 12 horas, enquanto outro, recebeu enoxaparina na dose de 1mg/Kg de 12 em 12 horas, doses preconizadas para tratamento do tromboembolismo em humanos. O terceiro grupo, controle, recebeu água destilada. Durante o experimento, os animais foram avaliados clinicamente e após 28 dias, sacrificados. Nos animais dos três grupos, a evolução clínica foi semelhante. Mediante análise anatomopatológica efetuada por estudo descritivo e quantitativo, foi observada presença de fibrose, cartilagem e osso igualmente nos três grupos, sempre com predomínio de tecido ósseo. O estudo biomecânico, realizado por intermédio de ensaios de flexão, demonstrou coeficiente de rigidez e carga máxima semelhantes nos três grupos. Nenhuma diferença clínica, anatomopatológica e biomecânica foi encontrada, resultando todas as fraturas em consolidação de acordo com os critérios adotados, concluindo-se, portanto, que a heparina sódica e a enoxaparina nas doses, via e tempo de administração utilizados não interfiriram na consolidação da fratura da tíbia do rato.

Investigation of the effect of unfractionated and low molecular weight heparins on inflammation and gastrointestinal mucosal injury in rats

The aim of the present work was to investigate the effect of unfractionated heparin [UFH; 1000-4000 IU/kg] in addition to three already marketed low molecular weight heparin [LMWH] preparations [nadroparin [1500-3000 anti-Xa IU/kg], tinzaparin [1500-3000 anti-Xa IU/kg], enoxaparin [300-600 anti-Xa IU/kg] on acute inflammation and on gastrointestinal mucosal integrity in rats. Acute inflammation was induced by intraplantar injection of carrageenan into rat hindpaw. Gastrointestinal mucosal injury was evoked by subcutaneous injection of indomethacin [20 mg/kg]. The results showed that: [1] Different heparin preparations given s.c., 30 mm prior to carrageenan injection exerted variable effects on the carrageenan oedema response. Oedema was not significantly changed after conventional UFH, but decreased after tinzaparin and nadroparin, the lower doses being more effective in reducing inflammation. Oedema was unchanged after enoxaparin at 600 IU/kg, but the lower dose of 300 IU/kg reduced oedema formation by 21.6% 1 h post-carrageenan.; [2] No significant change was noted in the number and severity of gastric mucosal lesions in rats treated with UFH. A significant decrease in number and severity of gastric mucosal lesions was noted in rats treated with the lower doses of either tinzaparin or enoxaparin compared with either the indomethacin control group or with the UFH [2000 IU/kg]-treated group. It is concluded that heparin preparations exert complex effects on acute [carrageenan-induced] inflammation and might have beneficial effects on gastric mucosal lesions caused by Indomethacin

Anticoagulantes: farmacología, mecanismos de acción y usos clínicos / Anticoagulants: pharmacology, mechanisms of action and clinical uses

El tratamiento anticoagulantes es una indicación frecuente en clínica, tanto en el área médica como en la quirúrgica. La presente es una revisión de la literatura internacional sobre los agentes anticoagulantes que con mayor frecuencia se utilizan en nuestro medio. Se enfatiza en los aspectos prácticos de esta terapia aclarando las indicaciones, las ventajas, las principales precauciones y el manejo de los efectos adversos de la heparina no fraccionada, las heparinas de bajo peso molecular y los anticoagulantes cumarínicos.

Tromboprofilaxia e bloqueio regional / Thromboprophilaxis and neuraxial blockade

Justificativa e Objetivos: No contexto das doenças vasculares periféricas, a doença venosa tromboembólica tem assumido maior importância, à medida em que se apresenta com freqüência e morbi-mortalidade elevadas e, sobretudo, pela possibilidade de alteraçäo de sua evoluçäo quando há reconhecimento e tratamento adequados. O uso cada vez mais freqüente de tromboprofiláticos tornou-se um problema para os anestesiologistas, uma vez que esses agentes têm aumentado a incidência de hematoma espinhal, quando associados a bloqueios regionais. Este trabalho tem o propósito de apresentar aos anestesiologistas, a partir de ampla revisäo de literatura, aspectos farmacológicos e bioquímicos dos anticoagulantes mais comumente utilizados e orientaçöes quando houver necessidade de bloqueio regional nos pacientes em esquema de anticoagulaçäo. Conteúdo: Säo apresentadas as características dos diferentes e implicaçöes no bloqueio regional. No final da descriçäo de cada fármaco, seguem-se consideraçöes a respeito das recomendaçöes mais importantes. Conclusöes: A realizaçäo de bloqueio regional, na vigência de tromboprofilaxia, exige redimensionamente das cautelas, principalmente nos aspectos concernentes à utilizaçäo de cateter peridural, punçöes repetidas e traumáuticas; pois, nestes casos, o risco da ocorrência de hematoma espinhal estará aumentado. Adicionalmente, fazem-se necessárias ampla comunicaçäo e preparo das equipes médica e de enfermagem quanto aos pacientes recebendo anticoagulantes, a fim de diminuir os riscos das complicaçöes hemorrágicas. Esses pacientes devem ser monitorizados minusiosamente, a fim de que sejam detectados precocemente sinais incipientes de compressäo medular. Se houver suspeita de hematoma espinhal, a confirmaçäo radiográfica deverá ser providenciada imediatamente, devido ao risco de isquemia medular irreversível

Development of new heparin-like compounds and other antithrombotic drugs and their interaction with vascular endothelial cells

The anticlotting and antithrombotic activities of heparin, heparan sulfate, low molecular weight heparins, heparin and heparin-like compounds from various sources used in clinical practice or under development are briefly reviewed. Heparin isolated from shrimp mimics the pharmacological activities of low molecular weight heparins. A heparan sulfate from Artemia franciscana and a dermatan sulfate from tuna fish show a potent heparin cofactor II activity. A heparan sulfate derived from bovine pancreas has a potent antithrombotic activity in an arterial and venous thrombosis model with a negligible activity upon the serine proteases of the coagulation cascade. It is suggested that the antithrombotic activity of heparin and other antithrombotic agents is due at least in part to their action on endothelial cells stimulating the synthesis of an antithrombotic heparan sulfate.

Profilaxis de la enfermedad tromboembólica venosa / Prophylaxis of the venous thromboembolism disease

El tromboembolismo pulmonar, en países desarrollados, es una de las causas más frecuentes de muerte en pacientes hospitalizados; constituye una complicación aguda de la trombosis venosa profunda, la cual es prevenible y, por lo tanto, es una causa de muerte evitable. Actualmente, aunque disponemos de métodos muy eficaces para prevenir esta enfermedad, no hay conciencia en la práctica médica que la profilaxis debe realizarse en forma sistemática en los pacientes de riesgo. En este artículo definiremos las diferentes categorías de riesgo, tanto en pacientes quirúrgicos como médicos, y los métodos más efectivos para la profilaxis en cada grupo, de acuerdo a los diferentes consensos nacionales e internacionales sobre la materia. No cabe duda que si logramos dicho objetivo estaremos atacando el grave problema sanitario que representa, tanto por su mortalidad como su morbilidad

Heparin and low molecular weight heparin decrease nitric oxide production by human polymorphonuclear cells

Background. Heparin and heparin derivatives with low anticoagulant activity exhibit a wide spectrum of biological functions affecting adhesion, activation and trafficking of luekocytes. Methods. We investigated the in vitro effect of heparin and low molecular weight heparin derivative (LMWH) on nitric oxide (NO) production by human polymorphonuclear leukocytes (PMN). Results. N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated NO production was significantly decreased by heparin at doses of 0.5 and 5 µg/mL, while LMWH was only effective at doses of 50 and 200 µg/mL by means of a mechanism not related to No synthase (NOS) activity. Conclusions. These results support the hypothesis that heparin and LMWH derivatives may offet therapeutic benefit for inflammatory diseases where No plays a protagonic role