The Effect of Neonatal Administration of Sex Hormones on the Turnover of Hepatic Microsomal Phospholipid in Male and Female Rats

Abstract

The effect of neonatal administration of testosterone propionate and oestradiol benzoate on the metabolism of microsomal phospholipid in the liver of male and female rats was studied. Males had a greater uptake of radioactive phosphorus than females. Gonadectomy at the age of 4 weeks reduced the incorporation of 32P into the microsomal phospholipid. Administration of testosterone significantly increased 32P uptake both in the intact and ovariectomized females as well as in the castrated males, whereas oestradiol produced no effect. A sex difference of total microsomal phospholipid phosphorus was also found in the gonadectomized rats. Oestrogen caused no change in the intact animals but restored the level of phospholipid in ovariectomized female rats. On the other hand, testosterone significantly increased the total content of the phospholipid in the liver microsomes of both intact and gonadectomized male and female rats.

Differentiation of Steroid Metabolism in the Rat and Mechanisms of Neonatal Androgen Action

“…There are, however, a few studies on general biochemical and morphological properties which tend to indicate the effect of neonatal hormone priming. The incorpora tion of 32 P into liver microsomal phospholipid is higher in male than in female rats and it is increased in females neonatally treated with androgen (82). The microsomal cytochrome P-450 complex, which takes part in enzymatic hydrox ylations in the liver, is sexually differentiated (76).…”