The absence of influence of chronic hyperinsulinemia on the development of renovascular hypertension in rats.
Our previous studies have shown that sustained hyperinsulinemia increases blood pressure in rats. The precise mechanism is still unclear. The present study was conducted to assess if hyperinsulinemia could interact with angiotensin II and other pressor stimuli to increase blood pressure in renovascular hypertensive rats. Intact and uninephrectomized Sprague-Dawley rats with unilateral renal arterial constriction (2-kidney, 1 clip and 1-kidney, 1 clip Goldblatt rats) were administered insulin (3 mU/kg/min) for 6-12 weeks. The clipped rats without insulin infusion and normal rats served as controls. Changes in blood pressure were measured by tailcuff method without preheating. Results showed that either sustained infusion of insulin or renal arterial clipping alone in normal rats significantly increased the blood pressure. Superimposed infusion of insulin for 6-7 weeks into rats with unilateral renal artery constriction in either 2-kidney or 1-kidney model did not accelerate nor exacerbate the development of hypertension. There were no significant differences in body weight and plasma levels of glucose, triglycerides, sodium and potassium between 2-kidney, 1 clip Goldblatt hypertensive rats with and without insulin infusion. These data suggest that chronic hyperinsulinemia and angiotensin II do not act synergistically to increase the blood pressure in rats.
Kau
M M
MM
National Taipei College of Nursing, Department of Physiology and Biophysics, Taiwan.
Tsai
L M
LM
Hsieh
P S
PS
Ko
G S
GS
Huang
W C
WC
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002908:Chronic Disease; D006946:Hyperinsulinism / Q000150:complications* / Q000503:physiopathology; D006978:Hypertension, Renovascular / Q000209:etiology* / Q000503:physiopathology; D007328:Insulin / Q000494:pharmacology; D008026:Ligation; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012077:Renal Artery
D007328:Insulin