Assuntos
Anafilaxia/fisiopatologia , Circulação Coronária , Reação Transfusional , Animais , Bradicardia/etiologia , Cães , Feminino , Hemodinâmica , Hipotensão/etiologia , Masculino , CoelhosRESUMO
An experimental study in dogs with intact thoracic cavity under morphine-chloralose narcosis featured coronary catheterization, extracorporeal perfusion and resistography as well as catheterization of the heart cavities and the coronary sinus. Hemodynamic and respiratory parameters were recorded simultaneously. PO2, PCO2 and pH were measured in the inflowing and outflowing blood. The effect of insulin on circulatory response in acute hypoxic hypoxia was examined before and after obsidan block of beta-adrenoreactive systems. Insulin administered after the obsidan beta-adrenergic block was found to limit coronary dilatation and reduce myocardial oxygen consumption in a more pronounced measure. It is suggested that the effect of insulin on coronary dilatation is due to reduced myocardial oxygen consumption resulting from its action on the heart's beta-adrenergic systems.
Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Circulação Coronária/efeitos dos fármacos , Hipóxia/tratamento farmacológico , Insulina/administração & dosagem , Propranolol/administração & dosagem , Animais , Cães , Sinergismo Farmacológico , Quimioterapia Combinada , Feminino , Hemodinâmica/efeitos dos fármacos , Hipóxia/fisiopatologia , Masculino , Miocárdio/metabolismo , Consumo de OxigênioRESUMO
The effect of a single insulin injection on the reaction of the coronary vessels to adrenaline, noradrenaline, and acetylcholine was studied in experiments on dogs. Insulin induces a decrease of arterial pressure and of the resistance of the coronary and peripheral vessels reduces the reflex cholinergic and beta-adrenergic reactions of dilatation of the coronary vessels, and promotes alpha-adrenergic reactions in intracoronary administration of adrenaline and noradrenaline. Insulin also weakens the immediate cholinergic reactions of the coronary vessels in stimulation of the effector systems with acetylcholine.
Assuntos
Vasos Coronários/efeitos dos fármacos , Insulina/farmacologia , Receptores Adrenérgicos/efeitos dos fármacos , Receptores Colinérgicos/efeitos dos fármacos , Animais , Circulação Sanguínea/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Pressão Venosa Central/efeitos dos fármacos , Cães , Feminino , Masculino , Fatores de Tempo , Resistência Vascular/efeitos dos fármacosRESUMO
Development of alloxan diabetes was accompanied in dogs by regular changes in the phasic structure of the cardiac contractions. Direction of the changes in the indices of phasic analysis in the groups of dogs with an average (up to 144.3 +/- 12.5 mg%) and marked (up to 258.0 +/- 22.8 mg%) increase in the blood sugar level was the same, but their expression increased with the elevation of hyperglycemia. In marked hyperglycemia there was established an increase (in comparison with normal values) of the index of myocardial tension, a shortening of the period of ejection, a decrease of the mechanical coefficient and of the intrasystolic index, this coinciding with the character of changes of the corresponding indices in the patients suffering from diabetes mellitus, depending on the severity of the disease. The data obtained pointed to the significant influence of metabolic changes (assessed by hyperglycemia level) on the contractile function of the heart.