Research on Cardiac Pressoreceptors

摘要

Pressoreceptor reflexes affecting coronary blood flow were investigated. No indication of reflexly induced changes of coronary vascular resistance has been found. Peripheral vegal stimulation resulted in a 25% increase in diastolic flow indicating vagal influence on the resistance of coronary vessels. Adrenaline injected into a coronary branch led to dilation prior to its effect on the contractile force of the heart. The effects of two representative catecholamines on coronary blood flow were investigated. Using a beta-receptor blocking agent, both constrictor and dilator effects have been observed following adrenergic stimuli. Separate pressure elevation in the main trunk of the left coronary artery caused peripheral dilation. Bradycardia was also observed. Although this is believed to be a part of a depressor reflex action, there is no evidence that there exists within the coronary vessels a separate reflexogenic area comparable in intensity to the aortic arch and carotid sinus. Moreover, branches from the aortic nerve must be assumed to be distributed as far as the coronary ostis. In such event, the coronary area must be considered to contribute a part of the systemic activation. (Author)