Phospholipid dependency of hepatic uridine diphosphate-glucuronyltransferase in the developing fetus of the rat.

The developmental change of uridine diphosphate-glucuronyltransferase (UDPGT) was studied using hepatic microsomes of rat fetuses on days 18 and 21 of gestation. Total phospholipid content was higher on day 21 than on day 18, although no significant difference in the composition between the two stages was observed. Lipid removal with phospholipase A2 greatly reduced UDPGT activity for phenol in the later stage of gestation, even though the delipidation ratios in both stages were similar. The fluidity in the hydrocarbon region of the microsomal membrane was higher on day 21 than on day 18. No significant difference in the polarization of N-dansylaziridinyl protein was observed between the stages.