Gonadal Steroid Effects on Plasma Lipoproteins and Individual Phospholipids

Abstract

The previously established effects of gonadal steroids on individual plasma phospholipids have been studied further in isolated lipoprotein fractions. For this purpose an estrogenic steroid (ethinylestradiol) alone and in combination with a gestagen with androgenic effect (norethisterone) was given for 3-week periods to 6 oophorectomized women. During ethinylestradiol administration the increase in plasma phospholipids was due mainly to an increase in the phospholipid fraction of highdensity- and very-high-density-lipoproteins (HDL-VHDL), (D > 1.063 g/ml) and the reduction in plasma cholesterol to a reduction in low-densitylipoproteins (LDL) (D 1.006–1.063 g/ml). The increase in plasma lecithin and cephalin and the decrease in plasma lysolecithin mirrored mainly corresponding changes in the HDL-VHDL. The addition of the gestagen-androgen used reversed the changes produced by the estrogen. The results obtained suggest an influence of these steroids on a) the liver synthesis of HDL-VHDL phospholipids, and b) the catabolism of very-low-density-lipoproteins (VLDL) (D < 1.006 g/ml) to LDL.