ACUTE HYPERTENSIVE RESPONSE TO SALINE INDUCED BY VANADATE, AN INSULINOMIMETIC AGENT

Objective: To investigate whether the reported insulin-like properties of vanadate may have hypertensinogenic actions in Sabra rats. Design: Comparison of [H-3]-deoxyglucose muscle uptake as well as blood pressure and its response to acute volume expansion and pressors infusions in 16 vanadate-treated (VT) and 12 control rats. Methods: Rats drank either tap water or 0.2 g/l vanadate for 4 weeks. A trace amount of [H-3]-deoxyglucose was administered intravenously to evaluate its plasma half-life and tissue uptake. Intra-arterial blood pressure was recorded in response to acute intravenous saline (4 ml/100 g body weight) and to incremental bolus injections of noradrenaline and angiotensin II (Ang II). Results: Skeletal muscle uptake of [H-3]-deoxyglucose was significantly higher in VT than in control rats. There was no difference between the blood pressure of VT or control rats; however, 2h after saline loading the mean intra-arterial blood pressure was significantly higher in VT than in control rats. The Ang II-induced blood pressure rise was also significantly higher in VT rats. Conclusion: The insulin-like activity of vanadate may be associated with salt-sensitive hypertension.