Angiotensin II의 이뇨작용

Diuretic Action of Angiotensin II in Dog

Angiotensin II, adminstered (infused or injected) intravenously, elicited the antidiuretic action with the decreased parameters of renal function at a small dose (0.0lmcg/kg/min), whereas, at a large dose (0.03, 0.1mcg/kg/min and 5.0mcg/kg), it produced the diuretic action accompanied the increased amounts of sodium and potassium excreted in urine (ENa and RK). At this time, glomerular filtration rates (GFR) were weakened slightly and renal plasma flows (RPF) were reduced markedly, and then filtration fractions (FF) were increased. Angiotensin II, infused into a renal artery, exhibited antidiuretic action at a small dose (0.003mcg/kg/min), and diuretic action at a large dose (0.0lmcg/kg/min), only in infused (experimental) kidney. The mechanism of the action was similar to the cases of the intravenous angiotensin II. The above results suggest that angiotensin II of a large dose produced diuretic action due to mechanism inhibiting reabsorption of electrolytes in renal tubules, mainly in proximal tubule in dog.