Comparative Reactivities of Aortic Strips from Hypertensive and Normotensive Rats to Epinephrine and Levarterenol

Rats were rendered hypertensive by two different technics. Isometric tensions developed by strips of aorta from these rats, when exposed to various concentrations of epinephrine and levarterenol, were compared with those developed by aortic strips from normotensive controls. Almost all of the aortic strips from the DCA-salt hypertensive rats responded with smaller contraction tensions to both pressor agents than did the corresponding control strips from the normotensive animals. The same was true for most of the strips obtained from the renal hypertensive rats. These results do not lend support to the hypothesis that vascular hyperreactivity is the basis of many forms of hypertension.