Novel aspects of cytokine action in porcine uterus--endometrial and myometrial production of estrone (E1) in the presence of interleukin 1beta (IL1beta), interleukin 6 (IL6) and tumor necrosis factor (TNFalpha)--in vitro study.

Interleukin 1beta (IL-1beta), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFalpha) increased (P < 0.05) estrone (E1) release from endometrial explants of pregnant pigs on days 10 to 11 after 12 h of tissue incubation in vitro with cytokines and on days 12 to 13 after 6 h of incubation. After 12 h of incubation on days 12 to 13 and 15 to 16 of pregnancy only IL6 increased E1 release. In non-gravid pigs IL1beta, IL6 and TNFalpha increased endometrial E1 release only on days 12 to 13 of the estrous cycle. The cytokines did not affect myometrial E1 release on days 10 to 11 and 15 to 16 ofpregnancy. On days 12 to 13 of pregnancy myometrial release of E1 was markedly increased in response to IL 1beta and IL6. In cyclic pigs only IL6 after 6 h of in vitro incubation increased myometrial E1 release on days 12 to 13 and 15 to 16. Progesterone (P4) increased both endometrial and myometrial release of E1 during the studied days of pregnancy and the estrous cycle, except for endometrial release on days 10 to 11 and 15 to 16 of the estrous cycle after 6 h of in vitro incubation. The results demonstrated that these cytokines may regulate the release of E1 both from the endometrium and myometrium harvested from gravid and non-gravid pigs. The results showed a pivotal role of IL 1beta, IL6 and TNFalpha in the regulation of E1 release in the porcine uterus in vitro.