Department of Reproductive Immunology and Pathology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland.
Anim Reprod Sci. 2011 Jan;123(1-2):89-97. doi: 10.1016/j.anireprosci.2010.10.015. Epub 2010 Nov 11.
Ovarian originated oxytocin (OT) is involved in several reproductive process, amongst them its role in the regulation/modulation of the estrous cycle in several species has been demonstrated. Although the systemic role of endometrial originated prostaglandins (PGs), especially prostaglandin F(2α) (PGF(2α)), is equivocal in cats, their possible involvement in the local regulation of uterine events during the estrous cycle is uncertain. We examined the spontaneous and LH-stimulated OT production in cultured luteal cells, the spatial and temporal arrangement of OT receptors (OTR) in a cat endometrium and, finally the effects of OT on PG secretion and prostaglandin-endoperoxide synthase (PTGS2) expression in the feline cultured endometrial cells. Uteri together with ovaries were collected from adult domestic cats (n=27) at different stages of the estrous cycle, after routine ovariohysterectomy procedures. The endometrial and luteal cells were separated enzymatically. Luteinizing hormone (LH) augmented OT secretion in cultured luteal cells 2-fold compared with control (P<0.05). Oxytocin receptor was abundantly expressed in different ovarian structure, as well as in uterine tissues collected at early/developing and mid-luteal phase. The secretion of PGF(2α) by endometrial epithelial cells was increased by OT at a dose 10(-7)M (P<0.001). Atosiban (specific OTR blocker) alone did not affect PG secretion but atosiban in combination with OT abolished the stimulating effect of OT on PGF(2α) secretion. Oxytocin augmented PGE(2) secretion at a dose 10(-7)M and 10(-6)M in the endometrial stromal cells (P<0.001). The treatment with atosiban did not abrogated positive effect of OT on PGE(2) production in the stromal cells. Effect of OT on PTGS2 mRNA expression, the rate-limiting enzyme in PG production, was examined by Real Time-PCR and PTGS2 mRNA expression was significantly affected by OT in both epithelial and stromal cell cultures (P<0.01). The present observations have shown that OT is locally produced by the early/developing corpora lutea and that corpora lutea delivered OT may regulate PG secretion in a cat endometrium especially at early- and mid-diestrus, by affecting PTGS2 mRNA expression.
卵巢源性催产素（OT）参与多种生殖过程，其在多种物种中对发情周期的调节/调制作用已得到证实。尽管子宫内膜源性前列腺素（PGs），尤其是前列腺素 F2α（PGF2α）在猫中的全身作用存在争议，但它们在发情周期中对子宫事件的局部调节中可能发挥作用尚不确定。我们研究了培养的黄体细胞中 OT 的自发和 LH 刺激产生，OT 受体（OTR）在猫子宫内膜中的时空排列，以及 OT 对 PG 分泌和猫培养子宫内膜细胞中前列腺素-内过氧化物合酶（PTGS2）表达的影响。从发情周期不同阶段的成年家猫（n=27）常规卵巢-子宫切除术手术后收集子宫和卵巢。酶法分离子宫内膜和黄体细胞。与对照相比，黄体生成素（LH）使培养的黄体细胞中 OT 的分泌增加了 2 倍（P<0.05）。OTR 在不同的卵巢结构以及在发情早期/发育和黄体中期采集的子宫组织中大量表达。OT 在 10（-7）M 剂量下增加子宫内膜上皮细胞中 PGF2α 的分泌（P<0.001）。阿托西班（OTR 特异性阻滞剂）单独使用不会影响 PG 分泌，但阿托西班与 OT 联合使用可消除 OT 对 PGF2α 分泌的刺激作用。OT 在 10（-7）M 和 10（-6）M 剂量下增加子宫内膜基质细胞中 PGE2 的分泌（P<0.001）。阿托西班的处理并没有消除 OT 对基质细胞中 PGE2 产生的积极影响。通过实时 PCR 检查 OT 对 PG 产生的限速酶 PG 合成酶 2（PTGS2）mRNA 表达的影响，OT 对上皮和基质细胞培养物中的 PTGS2 mRNA 表达均有显著影响（P<0.01）。本研究结果表明，OT 由早期/发育中的黄体产生，黄体产生的 OT 可能通过影响 PTGS2 mRNA 表达，在猫子宫内膜中特别是在发情早期和中期调节 PG 分泌。
