DNA synthesis and prostaglandin secretion by bovine endometrial cells as regulated by interleukin-1

Interleukin-1 (IL-1) is a pleiotropic cytokine which has been implicated in the regulation of endometrial function through alterations in proliferation, protein synthesis, and prostaglandin secretion. The objectives of this study were to determine if recombinant bovine interleukin-1 beta (rbIL-1 beta) stimulated prostaglandin secretion and altered the proliferation of bovine endometrial epithelial and stromal cells. Uterine flushes were also evaluated by enzyme-linked immunosorbent assay (ELISA) to determine if IL-1 beta was present in the bovine uterus. Effects of rbIL-1 beta (1-1000 ng mL-1) on DNA synthesis by endometrial epithelial and stromal cells prepared from cows at Days 11, 14 and 17 after oestrus were determined by monitoring uptake of [3H]thymidine into DNA. Incorporation of [3H]thymidine by epithelial cells was not affected by IL-1, but rbIL-1 beta inhibited [3H]thymidine incorporation by stromal cells. Secretion of prostaglandin E2 (PGE2), PGF2 alpha, and 13,14-dihydro 15-keto PGF2 alpha (PGFM) by epithelial and stromal cells was increased by rbIL-1 beta. Uterine flushes collected on Days 11, 14 and 17 after oestrus were positive for IL-1 regardless of pregnancy status, whereas flushes from pregnant cows on Day 25 and Day 30 did not have any detectable IL-1. In conclusion, IL-1 can be considered as a local regulatory factor of the bovine endometrium because of its presence within the uterus and its ability to alter DNA synthesis and prostaglandin secretion of endometrial cells.