Blood pressure in monkeys chronically exposed to psycho-emotional stress

The influence of experimental neurosis due to repeated conflict situations on blood pressure was studied in male monkeys. All animals developed hypertension demonstrable in the conscious state but which disappeared under pentobarbital anaesthesia. Both in conscious and anaesthetized animals, the pulse pressure was in-elevated. The hypertension was accompanied by increased plasma volume to interstitial volume ratio, due to a decrease of the interstitial fluid compartment. The plasma renin concentration was not raised. It is suggested that chronic increase in blood pressure might be responsible for the decrease in compliance of large arteries (as evidenced by increased pulse pressure). This form of hypertension does not depend on the activity of the renin-angiotensin system.