Different effects of furosemide on urinary excretion of prostaglandin E2and F2αin rabbits

Abstract

The effect of a constant infusion of furosemide (130 .mu.g/min i.v. for 60 min, n = 8) was studied on urinary excretion of water, electrolytes and immunoreactive prostaglandin E2 (iPGE2) and iPGF2.alpha. in chloralose-urethane anesthetized rabbits. During the furosemide infusion Na and water excretion increased 10-fold and the excretion of K and iPGE2 2-3 times. The excretion of iPGF2.alpha. (0.06 .+-. 0.03 .mu.g-min per 100 g kidney wt) was not significantly changed during the furosemide infusion, but increased markedly after the infusion and reached a maximum (1.0 .+-. 0.6 .mu.g/min per 100 g) 30-45 min later, while the small increase in iPGE2 excretion at this time could be attributed to cross-reaction with PGF2.alpha.. PGE2 might possibly be involved directly in the action of furosemide, while PGF2.alpha. might participate in Na and water conserving mechanisms in the rabbit kidney, activated by the drug induced diuresis.