Effects of Nifedipine and Platelet Activating Factor Antagonist (BN 52021) in Glycerol-Induced Acute Renal Failure in Rats

We studied the actions of nifedipine and the platelet activating factor (PAF) antagonist BN 52021 on renal and tubular function in glycerol-induced acute renal failure (Gly-ARF). The tubular handling of sodium was evaluated through the lithium clearance method in awake rats in metabolic cages. The sequential analysis of tubular function 3, 6, 12, and 24 h after Gly-ARF showed a sharp decrease in fractional proximal Na reabsorption (FPRNa—control 74.1 ± 12.5%, 3 h: 79.5 ± 6.0%; 6 h: 41.8 ± 15.9%; 12 h: 22.9 ± 17.9%; and 24 h: 31.1 ± 16.2% (p < 0.001) while fractional distal Na reabsorption (FDRNa) did not change during the study. The effect of nifedipine (20 mg/kg p.o.) and BN 52021 (1 mg/kg i.p.) were evaluated 24 h after the induction of Gly-ARF. Both drugs attenuated the reduction in creatinine clearance (control 431.8 ± 108.2, glycerol 96.7 ± 43.8, glycerol plus nifedipine 264.9 ± 103.5, and glycerol plus BN 52021 188.9 ± 69.8 μL/min/100 g, p < 0.001). However, only nifedipine could keep FPRNa higher t...