Nontoxic effect of tacrolimus on normally perfused isolated liver and protective effect on hypoperfused liver.

Background: Cyclosporine A has been shown to detrimentally affect post-transplantation vascular tone. Tacrolimus (FK506), an immunosuppressant whose mechanism of action is similar to that of cyclosporine A, is more potent in vitro and has a reportedly high level of safety. The effects of tacrolimus on hepatic vasculature and metabolism in isolated, dually perfused (through both the hepatic artery and porta) rat liver under normal conditions and again in association with a state of hypoperfusion followed by reperfusion, imitating the liver's clinical state during organ transplant, were investigated.