Cardioprotective effect of lipstatin derivative orlistat on normotensive rats submitted to cardiac ischemia and reperfusion

Abstract Purpose: To evaluate in vivo animal model of cardiac ischemia/reperfusion the cardioprotective activity of pancreatic lipase inhibitor of the orlistat. Methods: Adult male Wistar rats were anesthetized, placed on mechanical ventilation and underwent surgery to induce cardiac I/R by obstructing left descending coronary artery followed by reperfusion to evaluation of ventricular arrhythmias (VA), atrioventricular block (AVB) and lethality (LET) with pancreatic lipase inhibitor orlistat (ORL). At the end of reperfusion, blood samples were collected for determination of triglycerides (TG), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase-MB (CK-MB). Results: Treatment with ORL has been able to decrease the incidence of VA, AVB and LET. Besides that, treatment with ORL reduced serum concentrations of CK and LDL, but did not alter the levels of serum concentration of TG, VLDL and HDL. Conclusion: The reduction of ventricular arrhythmias, atrioventricular block, and lethality and serum levels of creatine kinase produced by treatment with orlistat in animal model of cardiac isquemia/reperfusion injury suggest that ORL could be used as an efficient cardioprotective therapeutic strategy to attenuate myocardial damage related to acute myocardial infarction.

Heparin modulates the expression of genes encoding pro and anti-apoptotic proteins in endothelial cells exposed to intestinal ischemia and reperfusion in rats

PURPOSE: To investigate if expression of genes encoding pro and anti-apoptotic proteins in the rat enteric endothelial cells stimulated by intestinal ischemia followed by reperfusion (IR) can be modified by treatment with heparin (HP). METHODS: Eighteen adult Wistar rats were divided in three groups: sham group submitted to laparotomy only (SG), ischemia followed by reperfusion group (IRG); ischemia followed by reperfusion plus pretreatment with HP 100 mg.kg-1 (IRG+HP). Ischemia was performed by clamping of the superior mesenteric artery. After 60 min of ischemia, metal clamps were removed for reperfusion for 120 min. Gene expression of encoding pro (Casp1, Casp6, Casp3, Cflar, Fas and Pgl) and anti-apoptotic (Bcl2, Bcl2l1 and Naip2) proteins in rat enteric endothelial cells was evaluated by PCR microarray method. RESULTS: Compared to rat endothelial cells of SG, the expression of pro-apoptotic genes was up-regulated in IRG while anti-apoptotic genes were down-regulated. In contrast, the expression of anti-apoptotic genes in IRG+HP was up-regulated while pro-apoptotic genes was down-regulated compared to SG. CONCLUSION: The attenuation by heparin of intestinal ischemia-reperfusion previously demonstrated in rodents could be related with ability of this drug to stimulate and reduce gene expression of encoding anti and pro-apoptotic proteins, respectively. .

Ischemic preconditioning and the gene expression of enteric endothelial cell biology of rats submitted to intestinal ischemia and reperfusion

PURPOSE: To investigate the effects of ischemic preconditioning (IPC) on the expression of pro and anti-apoptotic genes in rat endothelial cells undergoing enteric ischemia (I) and reperfusion (R). METHODS: Thirty rats underwent clamping of the superior mesenteric vessels. Sham group (GS) laparotomy only; Ischemia (GI): intestinal ischemia (60 min); Ischemia and Reperfusion (GIR): ischemia (60 min) and reperfusion (120 min); Ischemia and intestinal ischemic preconditioning (GI + IPC) : 5 minutes of ischemia followed by 10 min of reperfusion before sustained ischemia (60 min) ischemia and reperfusion and IPC (GIR + IPC): 5 min ischemia followed by 10 min of reperfusion before sustained ischemia (60min) and reperfusion (120 min). Rat Endothelial Cell Biology (PCR array) to determine the expression of genes related to endothelial cell biology. RESULTS: Gene expression of pro-apoptotic markers (Casp1, Casp6, Cflar, Fas, and Pgl) was down regulated in GI+IPC and in GIR + IPC. In contrast, the expression of anti-apoptotic genes (Bcl2 and Naip2), was up-regulated in GI + IPC and in GIR + IPC. CONCLUSION: Ischemic preconditioning may protect against cell death caused by ischemia and reperfusion.

L-arginine in the ischemic phase protects against liver ischemia-reperfusion injury / A L-arginina durante a fase isquêmica protege o fígado das lesões de isquemia e reperfusão

PURPOSE: To investigate the effects of intravenous L-arginine (LG) infusion on liver morphology, function and proinflammatory response of cytokines during the early phase of ischemia-reperfusion injury (IRI). METHODS: Thirty rabbits were subjected to 60 minutes of hepatic ischemia and 120 minutes of reperfusion. An intravenous injection of saline or L-arginine was administered five minutes before the ischemia and five minutes before initiating the reperfusion and at the 55th and 115th minutes after the ischemia. Samples were collected for histological analysis of the liver and measurements of the serum AST, ALT and LDH and the cytokines IL-6 and TNF-alpha. RESULTS: It was observed a significant reduction of sinusoidal congestion, cytoplasmic vacuolization, infiltration of polymorphonuclear leukocyte, nuclear pyknosis, necrosis and steatosis in liver tissue, as well as AST, ALT and LDH after injection of LG in the ischemia (p <0.001). Lower levels of IL-6 and TNF-alpha were associated with LG infusion during ischemia. Higher levels these proteins were observed in animals receiving LG during reperfusion. CONCLUSION: L-arginine protects the liver against ischemia/reperfusion injury, mainly when is administered during the ischemic phase.

OBJETIVO: Investigar os efeitos da infusão endovenosa da L-arginina (LG) na morfologia, função e resposta de citocinas pró-inflamatórias do fígado durante a fase precoce da lesão de isquemia e reperfusão (IRI). MÉTODOS: Trinta coelhos foram submetidos a 60 minutos de isquemia hepática e 120 minutos de reperfusão. Foi administrada injecção intravenosa de solução salina ou L-arginina aos cinco minutos antes de iniciar a isquemia e cinco minutos antes de iniciar a reperfusão e aos 55 e 115 minutos após o início da isquemia. Realizou-se análise histológica do fígado e dosagens séricas de AST, ALT, LDH, citocinas IL-6 e TNF-alfa. RESULTADOS: Ocorreu redução significante da congestão sinusoidal, vacuolização citoplasmática, infiltração de leucócitos polimorfonucleares, picnose nuclear, necrose e esteatose no tecido hepático, assim como nos níveis de AST, ALT e LDH após a injeção da LG na isquemia (p<0,001). Níveis mais baixos de IL-6 e TNF-alfa foram associados com a infusão LG durante a isquemia. Níveis mais elevados dessas proteínas foram observados nos animais que receberam LG durante a reperfusão. CONCLUSÃO: A L-arginina protegeu o fígado contra a lesão de isquemia e reperfusão principalmente quando administrada durante a fase de isquemia.

Percepçäo de sono: duraçäo, qualidade e alerta em profissionais da área de enfermagem / How nursing staff perceive the duration and quality of sleep and levels of alertness

Foi realizado um estudo entre auxiliares de enfermagem e enfermeiros que trabalhavam em hospital público de Säo Paulo. A organizaçäo dos turnos diurnos e noturnos fixos era de 12 horas diárias, seguidas de 36 horas de descanso. O objetivo deste estudo foi avaliar a percepçäo da duraçäo e qualidade dos episódios de sono nos dias de trabalho e de descanso, bem como dos níveis de alerta durante os turnos diurnos e noturnos de 12 horas de trabalho. Comparadas as duraçöes dos episódios de sono, foram detectadas diferenças significativas entre sono diurno e noturno (Teste t de Student = 10,82; p < 0,000). A qualidade dos episódios de sono diurno após as noites de trabalho foi percebida como pior do que a qualidade dos episódios de sono noturno (Teste de Wilcoxon, Z = 2,67; p < 0,007). Foram encontradas diferenças significativas na percepçäo dos estados de alerta em três momentos diferentes do turno da noite (Friedman = 63,0; p < 0,00). Os níveis percebidos de alerta à noite tornam-se piores à medida que aumenta o número de horas de trabalho. Isso é um indicativo de que a sonolência no trabalho noturno se faz presente e pode prejudicar seriamente tanto trabalhadores quanto os pacientes que estäo aos seus cuidados