Differential effects of oestradiol and progesterone on proliferation and morphology of cultured bovine uterine epithelial and stromal cells

Abstract

The effect of oestrogen and progesterone on the proliferation of cultured bovine uterine epithelial and stromal cells was assessed. Epithelial and stromal cells recovered from cows at day 1 to day 3 of the oestrous cycle were cultured in RPMI medium supplemented with 5% steroid-free fetal calf serum for 4 and 8 days. The addition of progesterone to the culture medium altered the morphology of stromal cells. Oestradiol (0.1-10 nmol l-1) and progesterone (50 nmol l-1) significantly increased the total DNA (from 9.6 +/- 0.96 to 25.6 +/- 0.99 micrograms per well, P < 0.001) and protein content (from 76.6 +/- 2.6 to 125.8 +/- 2.6 micrograms per well, P < 0.001) and decreased the ratio of protein to DNA (from 8.0 +/- 0.24 to 4.9 +/- 0.24, P < 0.01) in stromal cells during the first 4 days. During the second 4 days, the relative percentages of increase in DNA content were not affected by steroids, indicating that the major effect of steroids on stromal cell proliferation was exerted during the first 4 days of incubation. The morphology of epithelial cells was not influenced by the addition of steroids. DNA content of epithelial cells was reduced by the addition of oestrogen (from 22.9 +/- 2.1 to 15.0 +/- 2.0 micrograms per well, P < 0.01), but not progesterone (from 22.9 +/- 2.1 to 25.8 +/- 2.0 micrograms per well, P > 0.05). Total protein content of epithelial cells was reduced by oestradiol by day 4 (from 111.0 +/- 6.2 to 71.0 +/- 6.2 micrograms per well, P < 0.01), but not by day 8 (from 305.0 +/- 10.5 to 296.0 +/- 10.5 micrograms per well, P > 0.05). Progesterone increased the total protein content (from 305.0 +/- 10.5 to 366.0 +/- 10.5 micrograms per well, P < 0.01). Oestradiol significantly enhanced the ratio of protein to DNA in epithelial cells at day 8 (from 10.1 +/- 1.0 to 16.8 +/- 1.0, P < 0.01). These results show that oestradiol and progesterone have different effects on the proliferation and morphology of epithelial and stromal cells in vitro.