Role of prostaglandins and angiotensin II in experimental glomerulonephritis

Moderate autologous nephrotoxic serum nephritis (NSN) in rats causes no reduction in GFR despite a reduction in ultrafiltration coefficient (Kf) to less than one-half of normal. An increase in intraglomerular hydraulic pressure maintains GFR, but the signal and efferent mechanisms for this adaptation remain unknown. Indomethacin and saralasin were used to study the possible roles of prostaglandins and angiotensin II (A-II) in the adaptation to NSN. Indomethacin decreased renal blood flow (RBF) in NSN (-8.6%, P less than 0.001), but not in controls. Renal vascular resistance (RVR) increased in NSN (+ 9.6%, P less than 0.01), but decreased in controls (-5.6%, P less than 0.01). GFR decreased in NSN (-22.3%, P less than 0.01), but increased in controls (+ 10.3%, P less than 0.001). Urinary PGE2 excretion decreased markedly both in NSN and controls. With combined treatment using indomethacin and saralasin, RBF increased in NSN (+ 22.4%, P less than 0.001), but did not change in controls. RVR decreased in NSN (-21.5%, P less than 0.001), but was unchanged in controls. GFR remained unchanged both in NSN and controls. With saralasin alone, RBF increased both in NSN (+ 21.4%, P less than 0.001) and in controls (+ 14.4%, P less than 0.001). RVR decreased both in NSN (-21.8%, P less than 0.001) and controls (-18.7% P less than 0.001). GFR increased (+ 12.3%, P less than 0.05) in NSN, but did not change in controls. Urinary PGE2 excretion was increased in NSN compared to controls, decreased markedly in NSN after either indomethacin or saralasin infusion.(ABSTRACT TRUNCATED AT 250 WORDS)