High blood pressure induced by audiovisual stimulation in young rats: effect of antihypertensive agents.

High systolic blood pressure (BP) was induced in young Wistar rats by daily exposure for 30 mins to environmental stimuli consisting of intense (100 dB) sound of 7500 cps and flashing light (0.3 cps). Maximal BP enhancement was obtained after the application of both these stimuli for 3 consecutive days. Such a hypertensive response was detected 24 hrs, but not 1 hr after the trial. High BP backed to normal 72 hrs after discontinuation of the audiovisual stimulation trials. Clinically effective antihypertensive agents (clonidine, prazosin, propranolol, practolol and metoprolol) as well as a new compound under investigation (cicletanine) were proved active in this model. Normotensive nonstressed rats run in parallel did not show any variation in their BP after administration of the same dose of the drugs assayed. This experimental model of hypertension may be a useful tool not only to test new antihypertensive agents but also to study the intriguing question of the role of stress in the development and maintenance of essential hypertension.