EFFECT OF SYMPATHOADRENAL BLOCKADE ON THE HYPERGLYCEMIC ACTION OF ANGIOTENSIN-II

The present experiments were designed to investigate the influence of the sympathoadrenal system on the hyperglycemic action of angiotensin II in freely moving rats divided into four experimental groups: (1) sh am-operated animals submitted to intravenous administration of angiote nsin II (1.9 nmol) which caused a rapid increase in plasma glucose rea ching the highest values at 5 min after the injection (26.5% of the in itial values; P<0.01); (2) Sham-operated animals submitted to blockade of sympathetic noradrenergic pathways by treatment with guanethidine (10 mg/100 g body weight), which greatly decreased the baseline value of plasma glucose (85 +/- 5.5 mg% vs 136 +/- 5.1 mg% P<0.01), and incr eased the hyperglycemic response to angiotensin II by 96% (P<0.01); (3 ) Animals submitted to adrenodemedullation that did not alter the hype rglycemic response to angiotensin II; (4) Adrenodemedullated animals s ubmitted to sympathetic blockade by guanethidine treatment which cause d a 40.5% decrease in the hyperglycemic response to angiotensin II (P< 0.05). These data indicate that angiotensin II has a direct hyperglyce mic effect in addition to its action on sympathetic nervous system act ivation and adrenomedullary secretion.