Sorbitol clearance: a parameter reflecting liver plasma flow in the rat.
According to the clearance concepts, the functional liver plasma flow may be directly measured from the plasma kinetics of any substance whose hepatic intrinsic clearance largely exceeds liver perfusion. The present study was designed to ascertain the requirements for the reliability of D-sorbitol plasma clearance in evaluating changes of liver perfusion in the male Wistar rat. The plasma disappearance curve of D-sorbitol (3 mg/100 g b.w. by bolus i.v. injection) followed a first order kinetics and fitted a two-compartment model. Very similar estimates of D-sorbitol plasma clearance were obtained by applying the area under the curve method to data obtained by the trapezoidal rule and by compartmental analysis. D-sorbitol hepatic extraction was almost complete in controls and in rats submitted to porta-caval shunt and hepatic artery ligation, while significantly decreased after partial hepatectomy. Renal output never exceeded 10% of the administered amount. No in-vivo diffusion into red cells was observed. In controls, the functional liver plasma flow, as measured by D-sorbitol clearance was 2.83 +/- 0.68 ml/min/100 g (mean +/- SD). Significantly lower values were found in rats submitted to porta-caval shunt (1.19 +/- 0.38), hepatic artery ligation (2.06 +/- 0.53), and partial hepatectomy (1.03 +/- 0.44).
D000818:Animals; D004058:Diffusion; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008102:Liver Circulation; D008297:Male; D008657:Metabolic Clearance Rate; D051381:Rats; D011919:Rats, Inbred Strains; D013012:Sorbitol / Q000378:metabolism*
D013012:Sorbitol