PROTECTIVE EFFECTS OF DOPEXAMINE HYDROCHLORIDE IN RENAL-FAILURE AFTER ACUTE HEMORRHAGE IN ANESTHETIZED DOGS

1 The present studies are designed to investigate whether dopexamine hydrochloride, a DA-1 receptor and beta-2-adrenoceptor agonist, is effective in preventing renal failure in Wiggers model of haemorrhagic shock in dogs. 2 Pentobarbital anaesthetized dogs were allowed to bleed into a reservoir and a hypotensive state (40-50 mmHg) was maintained for 120 min; subsequently blood was reinfused and recoveries in renal blood flow (RBF) and in various parameters reflecting renal function were monitored for an additional 150 min. 3 In the vehicle treated control group, despite a 45% recovery in the RBF, renal function was totally impaired. In the dopexamine treated group, 80% recovery in RBF was accompained by 60-120% recoveries in various indices of renal function such as GFR, UV, U(Na)V, after reinfusion of the shed blood. These salutary effects of DPX were dose dependent and were abolished by a selective DA-1 antagonist, SCH 23390. 4 These data suggest that the renal vasodilatory, natriuretic and diuretic effects of dopexamine and its ability to restore renal function after haemorrhagic shock are due to a direct action on the renal vascular and tubular DA-1 receptors. These studies demonstrate potential therapeutic usefulness of this agent in preventing renal failure.