Reflexive blood pressure and heart rate responses of spontaneous hypertensive rats to electric shock

Abstract An examination was made of the blood pressure (BP) and heart rate (HR) responses of two groups of Okamoto-Aoki spontaneously hypertensive (SHR) rats and two groups of Wistar/ Kyoto (WKY) genetic control rats to unsignaled 1.5- or 5.0-sec 1.3-mA ac electric shocks applied through chest electrodes. Shock elicited brief pressor BP responses in both strains, followed by a depressor reaction in the WKY groups and a less precipitous fall in pressure in the SHR groups. Heart rate was generally accelerative in both strains. The results suggested that the SHR groups may have been less able to reflexively inhibit sympathetic output than were the WKY groups.