[Effects of acute changes in water balance on hydrosaluresis and on urinary excretion of prostaglandin E, in the presence and absence of a cyclooxygenase inhibitor].

Five healthy females were studied in order to evaluate the effects of a cyclo-oxygenase inhibitor agent (Indomethacin, I) on the hydro-saluresis and urinary excretion of prostaglandins (PG) of E series. Each subject was studied during both hypotonic polyuria (oral water load) and hypertonic olyguria (18 h water intake withheld). 1) In water diuresis I. treatment significantly (P less than 0.05) decreased urinary flow (36%) as well as sodium and potassium excretions (32%, 46%, respectively); the rise in urinary osmolarity (86%) and the fall in PGE excretion (63%) were statistically insignificant. 2) In antidiuresis I. treatment significantly (P less than 0.05) decreased urinary flow (50%) as well as sodium, potassium and PGE excretions (55%, 45%, 85%, respectively); furthermore urinary osmolarity was increased (26%, P less than 0.01). If I. renal effects are mediated by PG biosynthesis inhibition, the above data are consistent with an involvement of PG in hydrosaluresis control (at least in our experimental conditions).