摘要 : We have studied in the porcine endometrium the expression of oxytocin receptor (<i>OTR</i>) mRNA and the effect of progesterone (P₄) on oxytocin/oxytocin receptor (OT/OTR) function concerning intracellular Ca<sup>2+</su... 展开 We have studied in the porcine endometrium the expression of oxytocin receptor (<i>OTR</i>) mRNA and the effect of progesterone (P₄) on oxytocin/oxytocin receptor (OT/OTR) function concerning intracellular Ca²⁺ mobilisation ([Ca²⁺]_i), prostaglandin F2 alpha (PGF2 alpha ) and E2 (PGE2; PG) secretion. Tissue was taken from cyclic and early pregnant pigs (days 14-16). A higher expression of <i>OTR</i> mRNA (P<0.05) was observed in the endometrium of cyclic than pregnant pigs. The stimulatory (P<0.05) effect of OT (10^-7 M) on [Ca²⁺]_i mobilisation was noticed within 15-60 s and 30-60 s in endometrial stromal cells of cyclic and pregnant pigs, respectively. In the presence of P₄ (10^-5 M) basal and OT-stimulated [Ca²⁺]_i concentrations decreased in stromal cells during luteolysis and pregnancy. In stromal cells P₄ delayed mobilisation of [Ca²⁺]_i in response to OT by 15 s during luteolysis and had no effect during pregnancy. In cyclic and pregnant epithelial cells OT stimulated mobilisation of [Ca²⁺]_i in 45 s and 60 s, respectively. Oxytocin increased (P<0.05) PGF2 alpha secretion during luteolysis and pregnancy and PGE2 during luteolysis from endometrial slices. Progesterone did not inhibit this stimulatory effect. During luteolysis OT increased (P<0.05) PGF2 alpha in epithelial and stromal cells and PGE2 secretion in epithelial cells. In the presence of P₄ this effect of OT was reduced only in stromal cyclic cells (6 h culture). The presence of P₄ decreased the effect of OT on [Ca²⁺]_i mobilisation only in stromal cells. We found that, in most conditions, P₄ did not inhibit the OT-stimulated secretion of PG in the porcine endometrium. 收起