Frequency distribution of bilirubin intrinsic clearance in adult male sprague--dawley rats.
The intrinsic body clearance of bilirubin was determined in 48 adult male Sprague--Dawley rats that received an intravenous infusion of bilirubin. The intrinsic body clearance was calculated from the infusion rate, the steady-state plasma concentration of total (free and protein-bound) bilirubin, and the free fraction of bilirubin in plasma. The intrinsic body clearance of bilirubin ranged from 5.05 to 13.20 liters/kg/min and was bimodally distributed, with half of the animals in each group. The plasma free fraction of bilirubin ranged from 0.00025 to 0.00077 (mean 0.00053) in the 24 intrinsically rapid metabolizers of bilirubin and from 0.00048 to 0.00103 (mean 0.00075) in the intrinsically slow metabolizers of the pigment. Thus, interindividual differences in the total clearance of bilirubin in the rats are due to differences in both intrinsic body clearance and plasma protein binding.
D000818:Animals; D001663:Bilirubin / Q000097:blood / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D011485:Protein Binding; D051381:Rats; D013223:Statistics as Topic
D001798:Blood Proteins; D001663:Bilirubin