Epidermal growth factor receptors in porcine endometrium: binding characteristics and the regulation of prostaglandin E and F2 alpha production.

Epidermal growth factor (EGF) and its receptor have been implicated in the control of uterine cell growth and differentiation. The objectives of this study were to determine EGF binding characteristics and effects of EGF on prostaglandin (PG) production in vitro by glandular and stromal cells from porcine endometrium. Endometrial tissues were taken from 10 sows on Day 13 of pregnancy (first day of estrus = Day 0). Glandular and stromal cells were separated by enzymatic dispersion and sieve filtration and cultured for 3 days. EGF-binding assay was carried out at 20 degrees C in the presence of 0.2 nM 125I-EGF with increasing concentrations of unlabeled EGF (0-12 nM). Scatchard analyses revealed one class of high-affinity binding sites in each cell type with apparent equilibrium dissociation constants (n = 6) of 2.96 +/- 0.60 nM and 2.48 +/- 0.50 nM for stromal and glandular cells, respectively. The apparent binding capacities were 199.3 +/- 34.8 fmol/10(6) cells for stromal cells and 40.7 +/- 6.5 fmol/10(6) cells for glandular cells. Effects of EGF on PG production were determined by including 1, 5, 10, or 20 ng/ml EGF in the medium for the final 24 h of the 72-h culture. EGF increased PGE (p less than 0.01) and PGF2 alpha (p less than 0.05) secretion by stromal cells. The highest concentration (20 ng/ml) of EGF increased secretion of PGE and PGF2 alpha by 133% and 64%, respectively, over controls.(ABSTRACT TRUNCATED AT 250 WORDS)