Distribution of creatinine following intravenous and oral administration to rats.

Publisher Website
Google Scholar
Abstract
To evaluate the distribution of creatinine in rats, urinary, fecal and expiratory excretion, plasma levels and whole body autoradiography following i.v. or oral administration of [carbonyl-14C]creatinine was investigated. More than 90% of the exogeneous creatinine was excreted in the urine in 24 h following i.v. administration and both fecal and expiratory excretion were only .apprx. 1%. In case of oral administration, expiratory excretion could not be neglected, ranging from .apprx. 1-30%. Plasma creatinine concentration-time curves following the i.v. administration (70.4 .mu.g/kg or 400 mg/kg as creatinine) were analyzed according to a 2-compartment open model. There were significant but very small differences in the pharmacokinetic parameters for the 2 doses. When these parameters were compared with those of urea, k12 and k21, which are transfer rate constants between compartment 1 and 2, for creatinine were significantly smaller than those of urea. The k10 was larger in creatinine. (Vd'')extrap [apparent volume distribution] for creatinine was .apprx. 3 times that of urea. Whole body autoradiograms at 5 min following i.v. administration showed that exogeneous creatinine distributes with higher concentrations in liver, lung and kidney than in muscle and fat. This result was remarkably different from that of urea which distributes almost uniformly throughout the body at the same time. This difference observed in the autoradiograms would be the consequence of the fact that urea has larger k12 and k21 than creatinine.

This publication has 5 references indexed in Scilit: