Analysis of the reflex changes in the cardiovascular system following stimulation of the pericardial chemoreceptors. Report 2. The role of the heart and of various vascular fields in the development of the pressor reaction

Summary

Acute experiments were staged on cats under urethane anesthesia. As demonstrated, stimulation of pericardial chemoceptors by nicotine solution caused various arterial pressure changes: depressor, pressor or depressor-pressor reaction. As demonstrated in report 1,in effecting the pressor reaction the leading role was played by the vessels of the lungs, which deposited the blood as well as by decelerated cardiac rhythm. Stimulation of the pericardial chemoceptors by the nicotine pressor reaction was accompanied by reduction of the strength of cardiac conditions and often sistance of the vessels of the spleen, small intestine, kidneys, pelvic area and of extremities always increases. In experiments with temporary exclusion of various vascular areas from the general circulation it was shown that the main role in the rise of arterial pressure belonged to the vessels of the small intestine and of the spleen. Bilateral section of the splanchnic nerves and adrenalectomy eliminated the indicated pressor reaction. Participation of the hurnoral link in effecting this reaction was demonstrated in experiments on the isolated frog hearts.

A rise in arterial pressure in depressor-pressor reaction, which is a reflex compensation in response to the preceding arterial pressure reduction, is connected with the stimulation of the baroceptors of the sinocarotid and aortic zones and the effect from them on adrenal secretion.