Renal function in spontaneously hypertensive rats with insulin-exacerbated hypertension.
This study tests the hypothesis that in spontaneously hypertensive rats (SHR), insulin decreases natriuresis and diuresis and thereby contributes importantly to the hypertensive response to exogenous insulin administration. Seven week old SHR were given daily subcutaneous injections of either insulin (mixture of 5 U/Kg regular and 10 U/Kg NPH) or vehicle (isotonic saline). Within one week of treatment, systolic arterial pressure (SAP) was significantly higher in the insulin, compared to saline, treated SHR (184.2 +/- 2.5 vs. 158.3 +/- 4.0 mm Hg). However, twenty-four hour sodium and fluid excretion and the natriuretic and diuretic responses to an intravenous saline load were not affected either before or after the insulin-induced exacerbation of hypertension in SHR. Insulin treatment did not affect glomerular filtration rate, effective renal blood flow, or fractional excretion of Na+ or fluid. Therefore, our data do not support a major role for sodium and fluid retention in the insulin-induced exacerbation of hypertension in SHR.
Mozaffari
M S
MS
Department of Oral Biology/Pharmacology, School of Dentistry, Medical College of Georgia, Augusta 30912-1128, USA.
Roysommuti
S
S
Wyss
J M
JM
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004231:Diuresis / Q000187:drug effects*; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006973:Hypertension / Q000503:physiopathology*; D007004:Hypoglycemic Agents / Q000097:blood / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D007333:Insulin Resistance; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D051381:Rats; D011918:Rats, Inbred SHR; D012079:Renal Circulation / Q000187:drug effects
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin