Study for mechanism of retained placenta in cattle

第一项研究的目的是评价牛胎盘组织中孕酮、雌二醇-17 β、前列腺素E2（PGE 2）、前列腺素F2α（PGF 2 α）、催产素（OT）、催产素受体（OT-R）、内皮素-1和血管紧张素II（Ang II）的激素浓度与胎膜滞留（RFM）发生之间的关系。在分娩后立即（0 h）和6 h收集胎盘组织。通过酶免疫测定法测定RFM、非RFM和对照奶牛母体和胎仔胎盘组织中的激素浓度。RFM组、非RFM组和对照组之间P4和E2浓度无差异。RFM组胎盘母体部分的平均PGF 2 α浓度低于非RFM组和对照组。在母体组织中，RFM组的OT和OT-R浓度低于非RFM组分娩后0和6 h的浓度。此外，Ang II浓度 ...更多信息 RPM组胎盘组织中母体和胎儿部分的α 1/β 2有高于其他组的趋势。总之，目前的结果表明，ET-1和Aug II可能在胎盘单位中发挥不同的组织特异性作用，可能放大涉及OT的局部内分泌级联反应，OT-第二项研究的目的是确定妊娠期间胎盘组织中类固醇生成酶和蛋白水解酶的mRNA表达与妊娠期胎盘组织中类固醇生成酶和蛋白水解酶的表达之间的关系。牛分娩后释放胎膜的过程。根据分娩后胎膜的释放时间，将标本分为：1）早期组，即分娩后6 h内胎膜释放; 2）晚期组，即分娩后6 - 12 h胎膜释放。另外，对屠宰场的胎盘组织进行了检查，作为妊娠期样品，其胎龄通过冠臀长确定为第1个（0-3个月）、第2个（4-6个月）和第3个（7-9个月）三个月。子叶中甾体合成酶的mRNA表达量明显高于肉阜组织，P450 SCC和星星的mRNA表达模式在两种胎盘组织中趋于平行。另一方面，虽然在肉阜和子叶组织中的TIMP-2 mRNA的表达水平是相似的，MMP-2和MMP-9 mRNA的表达水平在妊娠期间和产后肉阜中比子叶组织高约10倍。此外，观察到在肉阜组织中的mmp-2和mmp-9以及在子叶组织中的mmp-9和timp-2在前和产后期间之间的八哥表达模式的显著变化。我们的研究结果表明，类固醇生成酶和mmps/timp-2的mRNA表达之间的关系可能有一个关键的作用，在维持妊娠和分娩后胎膜脱落。少

The aim of the first study was to evaluate the relationship between the occurrence of retention of the fetal membranes (RFM) and the hormonal concentrations of progesterone, estradiol-17β, prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α), oxytocin (OT), oxytocin receptor (OT-R), endothelin-1 and angiotensin II (Ang II) in the placental tissues of cattle. The placental tissues were collected immediately (0 h) and at 6 h after parturition. The hormonal concentrations were measured by enzyme immunoassay in maternal and fetal placental tissues from RFM, non-RFM and control cows. There were no differences in P4 and E2 concentrations among the RFM, non-RFM and control groups. The mean PGF2α concentration of the RFM group was lower than those of the non-RFM and control groups in the maternal part of the placenta. In maternal tissues, the OT and OT-R concentrations in the RFM group were lower than those at 0 and 6 h after parturition in the non-RFM group. Additionally, the Ang II concentrati … More on of the RPM group in both the maternal and fetal parts of placental tissues tended to be higher than those of the other groups. In conclusion, the present results suggest that ET-1 and Aug II may play differential tissue-specific roles in the placental unit that may amplify the local endocrinological cascade involving OT, OT-R and PGF2α interactions which are necessary for normal placental separation in the cow.The aim of the second study was to determine the relationship between mRNA expressions of steroidogenic and proteolytic enzymes in placentomes during gestation and the process of releasing fetal membranes after parturition in cattle. Based on the releasing time of fetal membranes after parturition, the specimens were classified as : 1)the early group, whereby the fetal membranes were released within 6 h after parturition ; and 2)the late group, whereby the fetal membranes were released 6 to 12 h after parturition. Placentomes from a slaughterhouse were additionally examined as samples for the gestation period, whose fetal age was determined as the 1st (0-3 months), 2nd (4-6 months) and 3rd (7-9 months) trimesters by crown rump length. Rather higher mRNA expressions of steroidogenic enzymes in cotyledon than caruncle tissues were observed, and the mRNA expression patterns of P450scc and star tended to be parallel in both placental tissues. On the other hand, although the expression levels of timp-2 mRNA in both caruncle and cotyledon tissues were similar, expression levels of mmp-2 and mmp-9 mRNA were approximately 10 times higher in caruncle than cotyledon tissue during gestation and postpartum. Moreover, marked changes in myna expression patterns between pre- and postpartum periods were observed in mmp-2 and mmp-9 in caruncle tissues and mmp-9 and timp-2 in cotyledon tissues. Our results suggest that the relationship between mRNA expressions of steriodogenic enzymes and mmps/timp-2 may have a critical role in the maintenance of pregnancy and fetal membrane detachment after parturition. Less