Participation of Prostaglandin E2 in Contractile Activity of Inflamed Porcine Uterus

Abstract

The aim of our study was to estimate the participation of prostaglandin E2 (PGE2) in the contractile activity of inflamed porcine uterus. On day 3 of the oestrous cycle, 50 ml of saline or 50 ml of Escherichia coli suspension, containing 109 colony-forming units/ml, was injected into each uterine horn in the control or experimental group, respectively. Seven days later the uteri were collected. Endometritis developed in all bacteria-inoculated gilts. Endometrium/myometrium and myometrium strips were incubated with PGE2 alone or together with PGE2 receptor (EP) subtypes (EP2, EP4, EP1 and EP3) blockers: AH 6809 (BEP2), ONO-AE2 (BEP4), ONO-AE3-240 (BEP1) and SC19220 (BEP3), respectively. In the control group, PGE2 (10-8 and 10-7 M) increased the intensity of contractions in endometrium/myometrium, and at the higher dose in myometrium. PGE2 (10-8 M) decreased the contraction intensity of the strips from inflamed uteri. After the use of BEP2, PGE2 (10-7 M) increased the values of this indicator in endometrium/myometrium and myometrium from the control gilts. In these animals, PGE2 (10-8 M) in the presence of BEP4 reduced the contraction intensity in endometrium/myometrium. In the bacterial group, PGE2 (10-8 M) in the presence of BEP2 and BEP4 enhanced the intensity of contractions in myometrium. Similar reaction was evoked by PGE2 (10-7 M) in endometrium/myometrium of the inflamed uteri in the presence of BEP4. The intensity of contractions in myometrium from the inflamed uteri significantly decreased after the use of BEP1 and PGE2 (10-7 M). PGE2 (10-7 M) administered after BEP3, significantly decreased the intensity of contractions in myometrium of the control gilts. These results show that PGE2 decreases the contraction intensity of inflamed porcine uteri. Further studies are needed to closely determine the role of PGE2 and other prostanoids in the contractile activity of inflamed uterine tissue.