Cardiovascular reactivity and design in rats with experimental “neurogenic hypertension”

The arterial barorecptors were denervated in 20 normotensive Wistar rats. 2 1/2 months after the operation their cardiovascular responses to "mental stress" were compared to those of matched control rats (NCR). At the time of investigation the blood pressure of the baroreceptor denervated rats (BDR) was increased some 15 per cent above that of the control group. There was, however, no difference in response to "mental stress" between groups, if anything the BDR reponded with less pronounced tachycardia. Two months subsequent to the stress-test the men blood pressure of the BDR was still significantly above normal levels, but the BDR did not exhibit structural cardiovascular adaptation, which has been documented in most types of stable hypertension as a response to the increased mean blood pressure. The results imply that hypertension induced by baroreceptor denervation is not of a stable and persistent type in which case structural changes in the cardiovascular system would have developed within the observation period (approximately 4 months). Emotional stimuli, however, do not seem to contribute to periodic blood pressure increase at the time of measurement, as earlier suggested.