EFFECTS OF THE PROSTACYCLIN ANALOG ILOPROST ON CYCLOSPORINE-INDUCED RENAL HYPOPERFUSION IN STABLE RENAL-TRANSPLANT RECIPIENTS

Background. The synthetic prostacyclin analogues have been proposed to protect against cyclosporin A (CsA) nephrotoxicity. The present study investigated the effect of infusion of the prostacyclin analogue ilop rost on the acute CsA-induced renal hypoperfusion and hypofiltration i n stable renal-transplant recipients. Methods. The study included 10 s table renal-transplant recipients with good graft function (s-creatini ne 90-170 mu mol/l). Renal function and the acute renal haemodynamic a nd tubular response to an oral CsA-dose (Sandimmun Neoral, 3 mg . kg(- 1)) were investigated with an infusion of iloprost (1 ng . kg(-1). min (-1)) or placebo on 2 separate days. After an overnight fast, seven 30 -min renal clearance periods were performed, two before infusion, thre e during infusion, and two recovery periods. An additional control cle arance study without CsA intake or iloprost/placebo infusion was done in eight of the patients. Results. CsA ingestion decreased ERPF and GF R significantly with a maximum decline at the end of the clearance stu dy. Iloprost infusion abolished the CsA-induced decrease in ERPF, but had no effect on the CsA-induced decrease in GFR, leading to a signifi cant decline in FF. Renal clearance of lithium (C-Li), used as an inde x of proximal tubular outflow, decreased in parallel with GFR after Cs A intake, with no additional effects of iloprost. Iloprost infusion de creased blood pressure and increased heart rate. Conclusion. Infusion of iloprost causes systemic and renal vasodilatation, but has no effec t on the CsA-induced decrease in GFR and C-Li in stable renal transpla nt recipients.