Endothelin-receptor blockade mitigates the adverse effect of preretrieval warm ischemia on posttransplantation renal function in rats

Background. Ischemia-reperfusion injury has been established as a nonimmunologic risk factor for the development of chronic graft nephropathy after renal transplantation. This objective of this study was to determine if oral administration of an endothelin-1 receptor (ET-R) antagonist over a 2-month period after renal transplantation would mitigate long-term dysfunction associated with 30 min of preretrieval warm ischemia (pre-WI). Methods. The left kidney was retrieved from 250-g Lewis rats. Recipients underwent left nephrectomy and isografting using standard techniques. Animals were divided into three groups: nonischemic controls (no pre-WI, n=8); ischemic controls (pre-WI only, n=6); and pre-WI kidneys in which recipients received the ET_A/B receptor antagonist, A182086, daily (30 mg/kg/ day) (pre-WI/ET-R antagonist, n=6). Isograft glomerular filtration rate (GFR) was measured at 2 months. Results. Measurement of GFR (mL/min) were as follows: no pre-WI, 2.1±0.26; pre-WI only, 1.24±0.14 (P<0.05 vs. no pre-WI); and pre-WI/ET-R antagonist, 2.3±0.45 (P<0.05 vs. pre-WI only and P=NS vs. no pre-WI). Conclusions. Chronic administration of a nonselective ET-R antagonist given after the ischemic insult, mitigated the decline in GFR at 2 months. These observations provide an experimental rationale for further investigation of the potential long-term protective effect of nonselective ET-R blockade versus ischemia-reperfusion injury in the clinical setting.