Vanadyl sulfate lowers plasma insulin and blood pressure in spontaneously hypertensive rats.
Spontaneously hypertensive rats (SHR) are hyperinsulinemic compared with their Wistar-Kyoto (WKY) controls. Since previous studies have demonstrated that vanadyl sulfate lowers insulin levels in nondiabetic rats, we used vanadyl to explore the relation between hyperinsulinemia and hypertension. In a prevention study, 5-week-old SHR and WKY rats were started on long-term vanadyl sulfate treatment. Vanadyl in doses of 0.4 to 0.6 mmol/kg per day lowered plasma insulin (252 +/- 22.8 versus 336 +/- 12.6 pmol/L, treated versus untreated, P < .01) and systolic blood pressure (158 +/- 2 versus 189 +/- 1 mm Hg, P < .001) in SHR without causing any change in plasma glucose. No changes were seen in the treated WKY rats. At 11 weeks of age, a group of untreated rats from the prevention study was started on vanadyl treatment as before. Again, vanadyl caused significant and sustained decreases in plasma insulin (264 +/- 12.6 versus 342 +/- 6.6 pmol/L, treated versus untreated, P < .001) and blood pressure (161 +/- 1 versus 188 +/- 1 mm Hg, P < .001) in SHR but had no effect in the normotensive WKY controls. Furthermore, restoration of plasma insulin in the vanadyl-treated SHR to pretreatment levels (subcutaneous insulin, 14,000 pmol/kg per day) reversed the effects of vanadyl on blood pressure (vanadyl with insulin, 190 +/- 3.0 mm Hg versus vanadyl without insulin, 152 +/- 3.0 mm Hg, P < .001). Since vanadyl treatment resulted in decreased weight gain, treated SHR were compared with a corresponding pair-fed group.(ABSTRACT TRUNCATED AT 250 WORDS)
Bhanot
S
S
Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
McNeill
J H
JH
D000375:Aging / Q000502:physiology*; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight; D006973:Hypertension / Q000503:physiopathology / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000097:blood*; D007677:Kidney Function Tests; D008111:Liver Function Tests; D015999:Multivariate Analysis; D051381:Rats; D011918:Rats, Inbred SHR / Q000502:physiology*; D011921:Rats, Inbred WKY / Q000502:physiology; D013599:Systole / Q000187:drug effects; D017968:Vanadium Compounds / Q000494:pharmacology*
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D017968:Vanadium Compounds; C034028:vanadyl sulfate; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase