EFFECT OF ESTRADIOL ON THE PHOSPHOLIPID BIOSYNTHESIS FROM CHOLINE-1, 2-¹⁴C, ETHANOLAMINE-2-¹⁴C AND SERINE-3-¹⁴C IN RAT UTERUS AND LIVER

Abstract

Aizawa and Mueller (1) reported that phospholipid biosynthesis in ovariectomized rat uterus is much more accelerated by a single injection of estradiol. Recently, in our laboratory, the acceleration of phospholipid metabolism by estradiol treatment was examined by using various ³²P compounds as substrate, and it was suggested that the biosynthesis of phosphorylethanolamine and phosphorylcholine in rat uterine tissue was much stimulated by the administration of estradiol (2). In the present work, metabolism of choline-1, 2-¹⁴C, DL-serine-3-¹⁴C, and ethanolamine-2-¹⁴C, which are all components of phospholipid, was investigated in uterus and liver of ovariectomized rat in vitro. Furthermore, the effect of estradiol on the incorporation of these compounds into phospholipid in liver was compared with rat uterus since there is a sex difference in lecithin formation and more lecithin is synthesized by stepwise methylation of phosphatidylethanolamine in female rat (3-5).