Effects of age and sex on rat bile acid metabolism.

Abstract

SummaryA study was made of the effects of age (1 through 450 days) and sex on bile acid half-lives, pool sizes, and spectra. No significant sex or age differences were found in the cholic or chenodeoxycholic pool half-lives. Chenodeoxycholic acid half-lives were considerably shorter than corresponding cholic acid half-lives in all groups (cholic acid ≅ 3.5 days; chenodeoxycholic acid ≅ 2.0 days). With respect to pool sizes, from 1 through 15 days the pools of females and males were equal in size and contained only cholic acid, possibly because the liver enzyme systems necessary for chenodeoxycholic acid synthesis had not yet developed. From 27 through 450 days, the pools of females contained major concentrations of both cholic and chenodeoxycholic acid. In contrast the male pools from 46 to 450 days contained only traces of chenodeoxycholic acid, along with cholic acid concentrations about equal to those of female rats. This lack of chenodeoxycholic acid in the male bile acid pool, which could result from...