Do high progesterone concentrations decrease pregnancy rates in embryo recipients synchronized with PGF2α and eCG?
Do high progesterone concentrations decrease pregnancy rates in embryo recipients synchronized with PGF2α and eCG?
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DOI：
10.1016/j.theriogenology.2003.07.012
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发表时间：
2004-05-01
期刊：
影响因子：
2.8
通讯作者：
Barros, CM
中科院分区：
文献类型：
--
作者：
Nogueira, MFG;Melo, DS;Barros, CM
本研究旨在评价马绒毛膜促性腺激素（eCG）处理对杂交母牛冷冻解冻（1.5 M乙二醇）胚胎移植后诱导副黄体（CL）数量、血浆孕酮浓度和妊娠率的影响。所有受试者在发情周期的随机阶段（第0天）接受500杯PGF2alpha (dl-氯前列醇，i.m)，观察7天的发情情况。第14天，将经PGF2alpha治疗后2 ~ 7天处于发情状态的母牛随机分为4组（每组83头），分别给予0（对照组）、200、400、600 IU eCG。2天后（第16天）给予PGF2a，观察其发情情况。发情后6 ~ 8 d，采集血浆测定孕酮浓度，超声观察卵巢结构。多胎或单胎直径小于15毫米的小母牛直接移植胚胎。优质的胚胎解冻后由同一位兽医移植给受者。胚胎移植（ET）后21天和83天分别行超声诊断和经直肠触诊证实妊娠。对照组、200组、400组和600组转移当天（发情周期第7天）血浆黄体酮浓度分别为3.9 +/- 0.7、4.2 +/- 0.4、6.0 +/- 0.4和7.8 +/- 0.6 ng/ml（对照组与治疗组P = 0.009； 200组与400组和600组P = 0.0001； 400组与600组P = 0.012）。对照组、200组、400组和600组的受孕率分别为41.9、50.0%、25.0%和20.9%（200组对400组和600组P = 0.0036）。综上所述，心电图治疗引起的孕酮浓度升高并不能提高ET受者的妊娠率。相反，血浆孕酮浓度最高的动物受孕率下降。(C) 2003 Elsevier Inc.版权所有。
The objective of this study was to evaluate the effects of equine chorionic gonadotropin (eCG) treatment on the number of induced accessory corpora lutea (CL), plasma progesterone concentrations and pregnancy rate in cross-bred heifers after transfer of frozen-thawed (1.5 M ethylene glycol) embryos. All recipients received 500 mug PGF2alpha (dl-cloprostenol, i.m.) at random stages of the estrous cycle (Day 0) and were observed for estrus for 7 days. On Day 14, heifers detected in estrus between 2 and 7 days after PGF2alpha treatment were randomly allocated to four groups (n = 83 per group) and given 0 (control), 200, 400, or 600 IU of eCG. Two days later (Day 16), these recipients were given PGF2a and observed for estrus. Six to eight days after detection of estrus, plasma samples were collected to determine progesterone concentration and ultrasonography was performed to observe ovarian structures. Heifers with multiple CL or a single CL >15 mm in diameter received an embryo by direct transfer. Embryos of excellent and good quality were thawed and transferred to the recipients by the same veterinarian. Pregnancy was diagnosed by ultrasonography and confirmed by transrectal palpation 21 and 83 days after embryo transfer (ET), respectively. Plasma progesterone concentrations on the day of transfer (Day 7 of the estrous cycle) were 3.9 +/- 0.7, 4.2 +/- 0.4, 6.0 +/- 0.4, and 7.8 +/- 0.6 ng/ml for groups Control, 200, 400, and 600, respectively (Control versus treated groups P = 0.009; 200 versus 400 and 600 groups P = 0.0001; and 400 versus 600 P = 0.012). Conception rates 83 days after ET were 41.9, 50.0, 25.0, and 20.9% for groups Control, 200, 400, and 600, respectively (200 versus 400 and 600 groups P = 0.0036). In conclusion, an increase in progesterone concentration, induced by eCG treatment, did not improve pregnancy rates in ET recipients. Conversely, there was a decline in conception rates in the animals with the highest plasma progesterone concentrations. (C) 2003 Elsevier Inc. All rights reserved.