ENDOTHELIN-1 AND IN-VITRO EVIDENCE OF RENAL-ARTERY VASOCONSTRICTION AFTER LIVER-TRANSPLANTATION

Twelve pigs underwent orthotopic liver transplantation. The mean endot helin-1 (ET-1) levels in the serum samples of the recipient animals 1 h after reperfusion of the graft (6.2+/-1.5 pg/ml) was significantly h igher (P<0.05) than in pretransplantation samples (3.2+/-0.6 pg/ml). S erum blood urea nitrogen (BUN) 24 h after transplantation was 13.8+/-5 .9 mg/dl, which was significantly higher than before transplantation ( 6.4+/-2.2 mg/dl). There was a positive correlation between the serum B UN and ET-1 (r=0.62, P<0.05). An in vitro isometric tension study was performed for the contractility response rate of the intact renal arte ry in the bath chamber containing the serum of the corresponding recip ient animals. The mean contractility response rates were higher with t he serum obtained after reperfusion of the graft (66.9+/-32.4%) than w ith those obtained before transplantation (18.3+/-9.2%) when compared to a standard contractility rate of 100% with 40 mM KCl. Moreover, the se contractility response rates were significantly reduced (32.8+/-21. 0%) with the addition of the ET-1 receptor antagonist FR139317. The re sults of the present study demonstrated that the liver transplantation was associated with elevation of ET-1 in the serum of the recipient a nimals. It was considered that ET-1 in the serum caused a direct vasoc onstriction of the renal artery in vitro. This may help to explain the renal dysfunction that is often seen in the recipients of clinical li ver transplantation.