LONG-TERM COMPLETE URETERAL OBSTRUCTION IN THE YOUNG-RAT

Complete obstruction of one ureter was created in 3-week-old weanling rats. The endothelin concentration in the renal tissue was measured by radioimmunoassay. In the obstructed kidney, a substantial increase wa s observed, after 1 week +90%, after 2 weeks +55%, and after 4 weeks 145% compared to the control rat kidneys. The endothelin-l /endothelin -3 ratio was found to be considerably raised, indicating a predominanc e of the vasoconstrictor effects of the - with reference to vasoactivi ty - bi-potential endothelin. Its contribution to vasoconstriction and to glomerular destruction in obstructive nephropathy is discussed.