[Prostaglandin E1 suppresses hypersecretion of antidiuretic hormone induced by surgical stress]

We studied the effects of prostaglandin E1 (PGE1) on decrease in urine output during surgery in patients for radical total hysterectomy under general anesthesia. The patients were randomly allocated into two groups. Five patients (control group) were given no PGE1 and served as control. Seven patients (PGE1 group) were given continuous infusion of PGE1 at a rate of 50 ng.kg-1 x min-1 after first measurement (baseline). Urine output in control group decreased by 68%, but in PGE1 group it did not change from the baseline. Urine sodium and fractional sodium excretion in control group decreased, but in PGE1 group they increased. Creatinine clearance increased from the baseline in both groups. Antidiuretic hormone in control group increased by 30%, but in PGE1 group decreased by 53%. Plasma renin activity, angiotensin I, angiotensin II in both groups increased, and those in the control group were higher than those in PGE1 group. However, aldosterone in the control group was lower than that in PGE1. These results indicate that diuretic effect of PGE1 could be mediated by suppression of antidiuretic hypersecretion induced by surgical stress, inhibition of the action of antidiuretic hormone, and suppression of sodium and water reabsorption in proximal and distal tubules. Also, PGE1 did not directly stimulate renin-angiotensin system.