Importance of NO/EDRF for glomerular and tubular function: Studies in the isolated perfused rat kidney

Importance of NO/EDRF for glomerular and tubular function: Studies in the isolated perfused rat kidney. The effect of the addition of Nω-nitro-L-arginine (L-NNA, 10 and 100 µM) to isolated rat kidneys perfused with a complex medium containing 21 amino acids has been studied. A cyclooxygenase inhibitor was added throughout to block prostaglandin synthesis. L-NNA caused significant reductions in renal perfusion flow rate (PFR, 9.8 ± 1.4 vs. 15.9 ± 1.1 ml · min -1 · g kidney wt -1 , P -1 · g kidney wt -1 , P -1 · g kidney wt -1 , P -1 · g kidney wt -1 , P -1 , P Gluc ) could be fully (L-NNA, 10 µM) or partially (L-NNA 100 µm) reversed by adding L-arginine (1 mM) to the perfusion medium. The observed results could be obtained in two different rat strains (Sprague-Dawley and Wistar). Only L-NNA and L-arginine caused the observed changes, while D-NNA and D-arginine were without effect. It is concluded that NO/EDRF is basally released from the isolated perfused rat kidney, and is of importance not only in the regulation of renal hemodynamics but also in the regulation of renal tubular function.