RESUMO
Effects of PF-10 the new fluorine-containing activator of ATP-dependent K-channels were investigated on the guinea-pig isolated heart. PF-10 enhanced myocardial contractility and decreased coronary vessels resistance in a dose-dependent manner. Low doses (10 mM/L, 1 mM/L) of PF-10 attenuates of the spontaneous alterations of heart rate, while high doses (0.1 mM/L) leds to these alterations. Previous activation of ATP-dependent K-channels by PF-10 has a cardioprotective effect during ischemia-reperfusion which a similar to the well-known phenomenon of ischemic preconditioning.
Assuntos
Trifosfato de Adenosina/metabolismo , Coração/efeitos dos fármacos , Precondicionamento Isquêmico Miocárdico , Canais de Potássio/agonistas , Traumatismo por Reperfusão/prevenção & controle , Vasodilatadores/uso terapêutico , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Cobaias , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Contração Miocárdica/efeitos dos fármacos , Canais de Potássio/metabolismo , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
It was produced plant-derived product, an omega-3 acid-enriched substrate (64%). In our study we tested the influence of this preparation, which is supposed a membrane-modifying agent, on the processes of damage to the isolated heart under conditions of ischemia-reperfusion. Animals took this substrate as nutrient addition to usually everyday diet. We assumed disorders in cardiodynamics and contractile functions of the myocardium (we measured a perfusion pressure in coronary vessel, left ventricular pressure and dp/dt) and in structure of cardiomyocytes. All mentioned parameters was much better after ischemia-reperfusion in hearts from animals which took an omega-3 acid-enriched substrate in course of 4 week before experiments than in hearts from control animals. Conclusions. Omega-3 polyunsaturated acids exert protective effect on functioning and structure of the isolated rat heart during ischemia-reperfusion.
Assuntos
Ácidos Graxos Ômega-3/farmacologia , Coração/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Gorduras Insaturadas na Dieta/isolamento & purificação , Gorduras Insaturadas na Dieta/farmacologia , Gorduras Insaturadas na Dieta/uso terapêutico , Avaliação Pré-Clínica de Medicamentos , Ácidos Graxos Ômega-3/isolamento & purificação , Ácidos Graxos Ômega-3/uso terapêutico , Ácidos Graxos Ômega-6 , Ácidos Graxos Insaturados/isolamento & purificação , Ácidos Graxos Insaturados/farmacologia , Ácidos Graxos Insaturados/uso terapêutico , Coração/fisiopatologia , Técnicas In Vitro , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Contração Miocárdica/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/ultraestrutura , Óleos de Plantas/isolamento & purificação , Óleos de Plantas/farmacologia , Óleos de Plantas/uso terapêutico , RatosRESUMO
Relative significance of cardiac and vessel components as well as the role of arachidonic acid metabolites in the development of endotoxic shock have been investigated in two series of experiments on the mongrel dogs. It is determined that endotoxin exerts no direct negative inotropic influence on the myocardium: blood pool in peripheral capacitance vessels plays a main role in the development of the first phase of the endotoxic shock (the first 30 min), that is a result of prostacyclin influence on these vessels, while in the subsequent phase it is a result of the bloodflow disturbance in the myocardium or arachidonic acid metabolites influence on the myocardium. Administration of endotoxin to the bloodflow significantly increased concentration of prostanoids; thromboxane A2 and prostacyclin in it. Indomethacin, inhibitor of prostaglandin synthesis, prevents development of the endotoxic shock.
