Changes of blood pressure and regional blood flow in SART rats and drug actions on these changes (author's transl)

Abstract

In order to investigate the function of the circulatory system in SART rats, systolic blood pressure and regional arterial blood flow were examined. It was found in SART stressed rats that the blood pressure was about 10 mmHg lower than that of the non-stressed group on the 6th day of stressing and after stressing, and such low blood pressure was maintained for several days. SART rats showed a decrease in the average blood flow value in the common carotid artery, increases in the average and instantaneous maximum blood flow values in the superior mesenteric artery, and the instantaneous maximum blood flow value in the abdominal aorta had a tendency to increase, though little changes were observed in the renal and the femoral arteries. It was suggested by flow contours that there was hardening in the vessel walls of the common carotid artery and the abdominal aorta, and softening in the superior mesenteric artery. SART stress-induced hypotension was further decreased by a single dose of guanethidine, clonidine, or hydralazine, but not by neurotropin. Continuous preadministration of neurotropin prevented the SART stress-induced hypotension and changes in blood flow. From the above mentioned results, the sympathetic nerve may be thought to be decreased in tension, or be depressed, in the circulatory system of SART rats.