Nephron filtration rate in conscious rats recovering from anesthesia

Abstract

Single-nephron glomerular filtration rate (SNGFR) of superficial (S) and juxtamedullary (JM) nephrons was measured in conscious rats with a 14C-ferrocyanide infusion technique. Experiments were carried out in nondiuretic (ND), salt-loaded (SL) and hemorrhagic hypotensive (HH) rats. Mean SNGFR values of S and JM nephrons were 48.7 .+-. 4.5 SE and 61.7 .+-. 4.2 in ND, 73.6 .+-. 8.7 and 87.5 .+-. 10.8 in SL, and 29.9 .+-. 5.9 and 36.4 .+-. 7.1 in HH rats. These values were higher than the values reported in anesthetized rats. The S-to-JM SNGFR ratio was not significantly different in the 3 experimental conditions (ND, 0.788 .+-. 0.032; SL, 0.843 .+-. 0.018; and HH, 0.824 .+-. 0.030), and did not differ from the values reported in anesthetized rats in similar experimental conditions. Anesthesia exerted a depressive effect on GFR, but did not modify intrarenal SNGFR distribution. Neither saline loading nor hemorrhagic hypotension induces SNGFR intrarenal redistribution in conscious rats.