Renal function in the obese Zucker rat.
The hyperphagic, genetically obese Zucker rat (fa/fa) exhibits both a greater kidney size and a progressive, premature glomerular sclerosis. In the present study, glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and renal tubular function were evaluated during study 1 in lean Zucker (FA/-), fa/fa, and lean Sprague-Dawley (S-D) rats. The GFR as measured by renal inulin clearance (ClIN) was not significantly different (P greater than 0.05) between S-D (1.36 +/- 0.18 ml/min) vs FA/- (1.36 +/- 0.33 ml/min) and FA/- vs fa/fa (1.25 +/- 0.42 ml/min). The ERPF as measured by renal p-aminohippurate (PAH) clearance (ClPAH) also was not significantly different between S-D (3.98 +/- 0.80 ml/min) vs Fa/- (3.71 +/- 0.81 ml/min) and Fa/- vs fa/fa (3.34 +/- 1.60 ml/min). There was a significant difference (P less than 0.05) in the renal tubular transport maximum (Tm) of PAH between S-D (2.23 +/- 0.40 mg/min) and Fa/- (1.64 +/- 0.63 mg/min) groups but not between Fa/- and fa/fa (1.29 +/- 0.61 mg/min) groups, indicating a strain effect in organic anionic renal transport. The Fa/- vs fa/fa comparisons were significant when GFR, ERPF and Tm were corrected for total body or kidney weight. In a second group of animals (study 2), GFR (as reflected by creatinine clearance [Clcr]) and histologic studies were performed in Fa/- and fa/fa rats. Clcr values were significantly higher in the fa/fa (2.10 +/- 0.44 ml/min) vs Fa/- (1.68 +/- 0.17 ml/min). Histologic studies in group 2 demonstrated no remarkable differences between Fa/- and fa/fa rats. These results suggest wide interanimal variation in obesity associated changes in renal function and possibly pathology in the fa/fa rat.
D000818:Animals; D001835:Body Weight; D005260:Female; D007668:Kidney / Q000473:pathology / Q000503:physiopathology*; D007677:Kidney Function Tests; D007684:Kidney Tubules / Q000503:physiopathology; D009399:Nephrons / Q000503:physiopathology; D009765:Obesity / Q000473:pathology / Q000503:physiopathology*; D009929:Organ Size; D051381:Rats; D011924:Rats, Zucker