ESTROGEN-RECEPTORS AND PROTEIN-SYNTHESIS IN CARUNCULAR AND INTERCARUNCULAR ENDOMETRIUM OF SHEEP BEFORE IMPLANTATION

Abstract

The rate of protein synthesis was higher in caruncular (P less than 0.05) and intercaruncular endometrium (P less than 0.01) of pregnant compared to non-pregnant ewes on Day 11 (Day 0 = day of oestrus), but not on Days 9, 13 and 15. Cytosolic oestrogen receptor concentrations (nmol/mg protein) were lower in caruncular endometrium of pregnant ewes than in non-pregnant ewes on Days 9 (P less than 0.02), 13 (P less than 0.05) and 15 (P less than 0.001) but not on Day 11. In intercaruncular endometrium, the receptor values were lower on Day 15 (P less than 0.02) of pregnancy compared to non-pregnancy, but not on the other days. The dissociation constant (0.75-2.55 x 10(-10) M) of oestradiol-17 b..