ACUTE EFFECTS OF DIFFERENT IMMUNOSUPPRESSIVE DRUGS ON PANCREATIC, ISLET, RENAL, AND ARTERIAL HEPATIC BLOOD-FLOW IN ANESTHETIZED RATS

The effects of four different immunosuppressive drugs on organ blood f low were investigated. Sprague-Dawley rats were injected intravenously with 0.2 ml of either 15-deoxyspergualin (DSG; 5 mg/kg body weight), RS 61443 (80 mg/kg body weight), FK 506 (0.5 mg/kg body weight), cyclo sporin A (9.5 mg/kg body weight), or the vehicles used. At 15 or 60 mi n after injection of the drugs, the blood perfusion of the whole pancr eas, the pancreatic islets, and the kidneys, as well as the arterial b lood flow to the liver, were measured in anesthetized animals using a microsphere technique. Fifteen minutes after administration, both FK 5 06 and DSG decreased the fraction of whole pancreatic blood flow diver ted through the islets. FK 506 and cyclosporin A reduced renal blood f low, but only 60 min after injection of the drug. None of the drugs in fluenced hepatic blood flow. RS 61443 did not affect the blood flow of the organ systems investigated. These differences in the effects of t he drugs tested on blood flow might have some important implications o n their efficacy and side effects. Thus, in view of its lack of influe nce on organ blood flow, RS 61443 seems to be preferable, at least whe n compared with cyclosporin A and FK 506 in the context of organ trans plantation.