THE K- EFFECT ON GLUCOSE-TOLERANCE AND INSULIN-SECRETION( CHANNEL OPENER PINACIDIL IN HYPERTENSION )

Many patients with essential hypertension have insulin resistance. Pin acidil exerts an anti-hypertensive action by opening the so-called ATP -sensitive potassium channels in vascular smooth muscle cells, Since p inacidil has been shown to inhibit insulin release in isolated beta ce lls, we investigated its effect on plasma glucose, serum insulin and s erum C-peptide before and during an intravenous glucose tolerance test (ivGTT) in 10 hypertensive patients. The plasma glucose disappearance rate (K-value) was not significantly changed by pinacidil [1.26(0.2)% /min with pinacidil vs. 1.46(0.19)%/min on control day]. Serum insulin levels rose from 7.2(1.8) and 6.5(0.7)mU/L to maximum levels of 52.2( 10.3) and 43.9(8.1)mU/L after 5 min (with and without pinacidil, respe ctively, N.S.). serum C-peptide levels rose from 0.55(0.07) and 0.55(0 .11)nmol/L to levels of 1.07(0.13) and 0.99(0.18)nmol/L after 5 min (w ith and without pinacidil respectively, N.S.). We conclude that pinaci dil has no significant effect on glucose tolerance and insulin secreti on during the ivGTT in patients with essential hypertension.