Dept. of HNFAS, University of Hawaii, 1955 East-West Road, Honolulu, HI 96822, USA.
Prostaglandins Other Lipid Mediat. 2010 Feb;91(1-2):42-50. doi: 10.1016/j.prostaglandins.2009.12.005. Epub 2010 Jan 7.
Loss of luteal progesterone secretion at the end of the ovine estrous cycle is via uterine PGF(2)alpha secretion. However, uterine PGF(2)alpha secretion is not decreased during early pregnancy in ewes. Instead, the embryo imparts a resistance to PGF(2)alpha. Prostaglandins E (PGE; PGE(1)+PGE(2)) are increased in endometrium and uterine venous blood during early pregnancy in ewes to prevent luteolysis. Chronic intrauterine infusion of PGE(1) or PGE(2) prevents spontaneous or IUD, estradiol-17beta, or PGF(2)alpha-induced premature luteolysis in nonbred ewes. The objective was to determine whether chronic intrauterine infusion of PGE(1) or PGE(2) affected mRNA for LH receptors, occupied and unoccupied receptors for LH in luteal and caruncular endometrium, and luteal function. Ewes received Vehicle, PGE(1), or PGE(2) every 4h from days 10 to 16 of the estrous cycle via a cathether installed in the uterine lumen ipsilateral to the luteal-containing ovary. Jugular venous blood was collected daily for analysis of progesterone and uterine venous blood was collected on day-16 for analysis of PGF(2)alpha and PGE. Corpora lutea and caruncular endometrium were collected from day-10 preluteolytic control ewes and day-16 ewes treated with Vehicle, PGE(1) or PGE(2) for analysis of the mRNA for LH receptors and occupied and unoccupied receptors for LH. Luteal weights on day-16 in ewes treated with PGE(1) or PGE(2) and day-10 control ewes were similar (P>or=0.05), but were greater (P<or=0.05) than in day-16 Vehicle-treated ewes. Progesterone profiles on days 10-16 differed (P<or=0.05) among treatment groups: PGE(1)>PGE(2)>Vehicle-treated ewes. Concentrations of PGF(2)alpha and PGE in uterine venous plasma on day-16 were similar (P>or=0.05) in the three treatment groups. Luteal mRNA for LH receptors and unoccupied and occupied LH receptors were similar (P>or=0.05) in day-10 control ewes and day-16 ewes treated with PGE(2) and were lower (P<or=0.05) in day-16 Vehicle-treated ewes. PGE(2) prevented loss (P<or=0.05) of day-16 luteal mRNA for LH receptors and occupied and unoccupied LH receptors. Luteal and caruncular tissue mRNA for LH receptors and occupied and unoccupied LH receptors were greater (P<or=0.05) on day-16 of PGE(1)-treated ewes than any treatment group. mRNA for LH receptors and occupied and unoccupied receptors for LH in caruncules were greater (P<or=0.05) in day-16 Vehicle or PGE(2)-treated ewes than in day-10 control ewes. It is concluded that PGE(1) and PGE(2) share some common mechanisms to prevent luteolysis; however, only PGE(1) increased luteal and endometrial mRNA for LH receptors and occupied and unoccupied LH receptors. PGE(2) prevents a decrease in luteal mRNA for LH receptors and occupied and unoccupied receptors for LH without altering endometrial mRNA for LH receptors or occupied and unoccupied receptors for LH.
绵羊发情周期末期黄体孕酮分泌的丧失是通过子宫 PG F(2)alpha 分泌实现的。然而，在绵羊妊娠早期，子宫 PG F(2)alpha 分泌并没有减少。相反，胚胎赋予了 PG F(2)alpha 抗性。在绵羊妊娠早期，子宫内膜和子宫静脉血中的前列腺素 E(PGE; PGE(1)+PGE(2))增加，以防止黄体溶解。在非繁殖绵羊中，慢性宫内输注 PGE(1)或 PGE(2)可防止自发性或 IUD、雌二醇-17β或 PG F(2)alpha 诱导的黄体过早溶解。目的是确定慢性宫内输注 PGE(1)或 PGE(2)是否影响黄体和 caruncular 子宫内膜中 LH 受体、LH 占据和未占据受体的 mRNA 以及黄体功能。在发情周期的第 10 天至第 16 天，通过安装在含有黄体的卵巢同侧子宫腔中的导管，每天每 4 小时向绵羊输注载体、PGE(1)或 PGE(2)。每天采集颈静脉血分析孕酮，在第 16 天采集子宫静脉血分析 PG F(2)alpha 和 PGE。在第 10 天预黄体溶解的对照绵羊和第 16 天用载体、PGE(1)或 PGE(2)治疗的绵羊中采集黄体和 caruncular 子宫内膜，用于分析 LH 受体和 LH 占据和未占据受体的 mRNA。在接受 PGE(1)或 PGE(2)治疗的绵羊和第 10 天对照绵羊的第 16 天黄体重量相似(P>or=0.05)，但高于第 16 天载体治疗的绵羊(P<or=0.05)。第 10-16 天的孕酮谱在治疗组之间存在差异(P<or=0.05)：PGE(1)>PGE(2)>载体治疗的绵羊。第 16 天子宫静脉血浆中 PG F(2)alpha 和 PGE 的浓度在三组治疗中相似(P>or=0.05)。第 10 天对照绵羊和第 16 天接受 PGE(2)治疗的绵羊的黄体 LH 受体和未占据和占据的 LH 受体的 mRNA 相似(P>or=0.05)，而第 16 天载体治疗的绵羊的 mRNA 则较低(P<or=0.05)。PGE(2)防止第 16 天黄体 LH 受体和占据和未占据的 LH 受体的丢失(P<or=0.05)。PGE(1)治疗的绵羊的黄体和 caruncular 组织中 LH 受体和占据和未占据的 LH 受体的 mRNA 更大(P<or=0.05)。在第 16 天，载体或 PGE(2)治疗的绵羊的 caruncles 中的 LH 受体和占据和未占据的 LH 受体的 mRNA 大于第 10 天的对照绵羊(P<or=0.05)。结论是 PGE(1)和 PGE(2)具有一些共同的机制来防止黄体溶解;然而，只有 PGE(1)增加了黄体和子宫内膜的 LH 受体和占据和未占据的 LH 受体的 mRNA。PGE(2)防止黄体 LH 受体和占据和未占据的 LH 受体的减少，而不改变子宫内膜的 LH 受体或占据和未占据的 LH 受体的 mRNA。
