Cardiovascular reactivity in renal and spontaneously hypertensive rats.

Pressor reactivity to noradrenaline or vasopressin was studied in unanaesthetized, pithed and isolated perfused hindquarter, preparations from renal and spontaneously hypertensive rats. Unanaesthetized renal and spontaneously hypertensive rats showed hyperreactivity to noradrenaline and vasopressin. Vascular responses of noradrenaline in pithed and isolated perfused hindquarter preparations were to a lesser extent but significantly greater in the renal hypertensive rat, while responses of pithed and isolated perfused hindquarter preparations to noradrenaline were within normal limits in the spontaneously hypertensive rat.