CrataBL, a lectin and Factor Xa inhibitor, plays a role in blood coagulation and impairs thrombus formation.

Arterial thrombosis is an important complication of diabetes and cancer, being an important target for therapeutic intervention. Crataeva tapia bark lectin (CrataBL) has been previously shown to have hypoglycemiant effect and also to induce cancer cell apoptosis. It also showed inhibitory activity against Factor Xa (Kiapp=8.6 µm). In the present study, we evaluated the anti-thrombotic properties of CrataBL in arterial thrombosis model. CrataBL prolongs the activated partial thromboplastin time on human and mouse plasma, and it impairs the heparin-induced potentiation of antithrombin III and heparin-induced platelet activation in the presence of low-dose ADP. It is likely that the dense track of positive charge on CrataBL surface competes with the heparin ability to bind to antithrombin III and to stimulate platelets. In the photochemically induced thrombosis model in mice, in the groups treated with 1.25, 5.0, or 10 mg/kg CrataBL, prior to the thrombus induction, the time of total artery occlusion was prolonged by 33.38%, 65%, and 66.11%, respectively, relative to the time of the control group. In contrast to heparin, the bleeding time in CrataBL-treated mice was no longer than in the control. In conclusion, CrataBL was effective in blocking coagulation and arterial thrombus formation, without increasing bleeding time.

Paradoxical effects of brain death and associated trauma on rat mesenteric microcirculation: an intravital microscopic study.

OBJECTIVE: Experimental findings support clinical evidence that brain death impairs the viability of organs for transplantation, triggering hemodynamic, hormonal, and inflammatory responses. However, several of these events could be consequences of brain death-associated trauma. This study investigated microcirculatory alterations and systemic inflammatory markers in brain-dead rats and the influence of the associated trauma. METHOD: Brain death was induced using intracranial balloon inflation; sham-operated rats were trepanned only. After 30 or 180 min, the mesenteric microcirculation was observed using intravital microscopy. The expression of Pselectin and ICAM-1 on the endothelium was evaluated using immunohistochemistry. The serum cytokine, chemokine, and corticosterone levels were quantified using enzyme-linked immunosorbent assays. White blood cell counts were also determined. RESULTS: Brain death resulted in a decrease in the mesenteric perfusion to 30%, a 2.6-fold increase in the expression of ICAM-1 and leukocyte migration at the mesentery, a 70% reduction in the serum corticosterone level and pronounced leukopenia. Similar increases in the cytokine and chemokine levels were seen in the both the experimental and control animals. CONCLUSION: The data presented in this study suggest that brain death itself induces hypoperfusion in the mesenteric microcirculation that is associated with a pronounced reduction in the endogenous corticosterone level, thereby leading to increased local inflammation and organ dysfunction. These events are paradoxically associated with induced leukopenia after brain damage.

Paradoxical effects of brain death and associated trauma on rat mesenteric microcirculation: an intravital microscopic study

OBJECTIVE: Experimental findings support clinical evidence that brain death impairs the viability of organs for transplantation, triggering hemodynamic, hormonal, and inflammatory responses. However, several of these events could be consequences of brain death-associated trauma. This study investigated microcirculatory alterations and systemic inflammatory markers in brain-dead rats and the influence of the associated trauma. METHOD: Brain death was induced using intracranial balloon inflation; sham-operated rats were trepanned only. After 30 or 180 min, the mesenteric microcirculation was observed using intravital microscopy. The expression of Pselectin and ICAM-1 on the endothelium was evaluated using immunohistochemistry. The serum cytokine, chemokine, and corticosterone levels were quantified using enzyme-linked immunosorbent assays. White blood cell counts were also determined. RESULTS: Brain death resulted in a decrease in the mesenteric perfusion to 30 percent, a 2.6-fold increase in the expression of ICAM-1 and leukocyte migration at the mesentery, a 70 percent reduction in the serum corticosterone level and pronounced leukopenia. Similar increases in the cytokine and chemokine levels were seen in the both the experimental and control animals. CONCLUSION: The data presented in this study suggest that brain death itself induces hypoperfusion in the mesenteric microcirculation that is associated with a pronounced reduction in the endogenous corticosterone level, thereby leading to increased local inflammation and organ dysfunction. These events are paradoxically associated with induced leukopenia after brain damage.

Effect of glycemic state in rats submitted to status epilepticus during development.

The effect of glycemic state on status epilepticus (SE) development was studied in animals of different ages, submitted to pilocarpine model of epilepsy. Groups: I- Rats with 9-day-old (P9): IA. Submitted to 1SE; IB. Saline-treated; IC. Induced- hyperglycemia; ID. Induced- hyperglycemia+SE; II- Rats submitted to three consecutive episodes of SE at P7, P8 and P9; III- Rats submitted to 1SE at P17; IV- Rats submitted to 1SE at P21. Hippocampal cell death and the expression of glucose transporter GLUT3 were analyzed in group I. The results demonstrated normoglycemia in the groups IA, IB and II, hypoglycemia in group III and hyperglycemia in group IV, showing that the glycemia during SE is age dependent. Induced hyperglycemia during SE in P9 protected the hippocampal neurons from death and both groups IC and ID presented increased GLUT3 expression, showing high glucose consumption by the hippocampus.

Effect of glycemic state in rats submitted to status epilepticus during development

O efeito do estado glicêmico sobre o desenvolvimento do status epilepticus (SE) foi estudado em animais de diferentes idades, submetidos ao modelo de epilepsia por pilocarpina. Grupos: I- Ratos com nove dias (P9): IA- Submetidos a 1SE; IB- Tratados com salina; IC- Hiperglicemia induzida; ID- Hiperglicemia induzida+SE; II- Ratos submetidos a 3 episódios consecutivos de SE em P7, P8 e P9; III- Ratos submetidos a 1SE em P17; IV- Ratos submetidos a 1SE em P21. Foram analisados no grupo I a morte celular hipocampal e a expressão do transportador de glicose GLUT3. Os resultados mostraram haver normoglicemia nos grupos IA, IB e II, hipoglicemia no grupo III e hiperglicemia no grupo IV, sendo a glicemia durante o SE, idade dependente. A hiperglicemia induzida durante o SE em P9 protegeu neurônios hipocampais e os grupos IC e ID apresentaram expressão aumentada de GLUT3, mostrando aumento no consumo de glicose pelo hipocampo.