[The effects of the stellate ganglion electrostimulation on the coronary circulation of the dog (author's transl)].

In this study we have investigated the effects of the stellate ganglion electrostimulation on the perfusion pressure of coronary vascular bed perfused at constant flow. We always observed systemic hypertension and two kinds of response in the coronary district: vasodilatation or vasoconstriction. These responses were blocked by propranolol and phentolamine i.a. administration respectively, while both the phenomena were blocked by i.v. infection of guanethidine. These results seem to suggest that nervous sympathetic stimulation induces catecholamines release by means of either pregangliar adrenergic fibers directed to coronary vessels either postgangliar adrenergic fibres directed to the myocardium. The occurrence of vasodilatation or vasoconstriction could be explained by the prevalent stimulation of myocardial or coronary adrenoceptors.