Effect of OP-41483, a PGI₂ derivative, in burned rabbits

with special reference to renal function

Abstract

It is known that the number of platelets decreases after burn injury. However, the mechanism of such a decrease and its influence on systemic organs have not been fully elucidated. In this study, we evaluated the efficacy of OP-41483 (a derivative of the PGI₂) in burned rabbits with special reference to its association with renal function. Third-degree burns, covering 35% of the total body surface area, were experimentally produced on the back of rabbits. Among the following five groups of rabbits (6 rabbits each), the time courses of renal function and platelet function were compared; Group I (no treatment), Group II (fluid therapy only), Group III (treated with OP-41483+fluid therapy; a: 50ng/kg/min, b: 75ng/kg/min, c: 100ng/kg/min).
The results show that in Group I, all rabbits died after 8 hours. Renal function testes in this group showed a decrease in creatinine clearance and increases in FeNa and CH₂O. Such changes were improved in Groups III-b, III-a and II (in order of the degree of improvement). Group III-c showed no improvement. As for the platelets the decrease in platelets was the smallest in Group III-b, where platelets showed no decrease until 8 hours after injury and fibrinogen registered a satisfactory course of increasing. No improvement was found in Group III-c by our tests, presumably owing to an overdose of OP-41483. The optimal dose of OP-41483 for improving the renal function of burned rabbits was 75ng/kg/min in our study.