HETEROGENEITY OF VASCULAR DNA SYNTHESIS IN RESPONSE TO THE DEVELOPMENT OF GOLDBLATT TWO-KIDNEY, ONE CLIP HYPERTENSION

Abstract

To examine the changes in the rate of DNA synthesis in the aorta and mesenteric and subcutaneous resistance arteries during the development of renovascular hypertension. Goldblatt two-kidney, one clip hypertensive and sham-operated control rats were studied 3, 7, 14 and 28 days after surgery. DNA synthesis was measured as the hourly rate of [3H]-thymidine incorporation into the DNA. Three days after renal artery constriction there was a significant increase in the DNA synthesis in both the aorta and the mesenteric vessels, although the blood pressure was not changed. DNA synthesis was elevated during the development of hypertension, but returned to control levels after 28 days when the blood pressure had reached a plateau. By contrast, there was no increase of DNA synthesis in the subcutaneous vessels at any time after renal artery constriction. The plasma renin concentration also was increased after 3 days in the clipped rats and remained elevated throughout the study. There were no significant changes in the blood pressure, the plasma renin concentration or the rate of vascular DNA synthesis in the sham-operated control rats. These data indicate that there are regional differences in the vascular response to the induction of renovascular hypertension and that in some vascular beds an increase in DNA synthesis precedes the rise in blood pressure.