Contractility of intrarenal arteries in Goldblatt hypertensive rabbits.

Abstract

The present investigation contractile responses of microdissected intrarenal arcuate arteries from sham-operated rabbits and two-kidney, one clip Goldblatt hypertensive rabbits at 2 and 12 weeks after procedure. Arcuate arteries from both kidneys of the sham-operated rabbits and stenotic and nonstenotic kidneys of the Goldblatt hypertensive rabbits were studied. Mean arterial blood pressures of the sham-operated and Goldblatt hypertensive rabbits were 72 +/- 2 and 85 +/- 2, and 130 +/- 3 and 125 +/- 4 mm Hg at 2 weeks and 12 weeks, respectively. In vitro isometric contractile force measurements were made with a small-artery myograph. Responses to graded concentrations of norepinephrine were evoked in the arcuate arteries, and the maximum active force was developed and -log EC50 was determined. At 2 weeks after procedure, the maximum responses of the vessels from the left kidney of the sham-operated rabbits and those from the stenotic left kidney of the Goldblatt hypertensive rabbits did not differ. The responses of the vessels from the right kidney of the sham-operated rabbits did not differ from those of the nonstenotic right kidney of the hypertensive rabbits. A markedly depressed maximum response of the vessels from the nonstenotic kidney of the hypertensive as compared with the right kidney of the sham-operated rabbits was found at 12 weeks after procedure, whereas the vessels from the stenotic kidney of the hypertensive and the left kidney of the sham-operated rabbits exhibited almost identical maximal responses. Responses to U 46619 were similarly affected in the two groups of rabbits. Cold-induced contractile responses of the arcuate arteries from the nonstenotic kidney of the hypertensive rabbits did not differ from those of the sham-operated rabbits at the 12-week interval.(ABSTRACT TRUNCATED AT 250 WORDS)