Okada Carolina T C, Kaps Martim, Perez Quesada Javier, Gautier Camille, Aurich Jörg, Aurich Christine
Platform Artificial Insemination and Embryo Transfer, Department for Small Animals and Horses, Vetmeduni Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Section for Obstetrics, Gynaecology and Andrology, Department for Small Animals and Horses, Vetmeduni Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Animals (Basel). 2020 Nov 30;10(12):2249. doi: 10.3390/ani10122249.
Spontaneous prolongation of the luteal phase has been described in horses, but the underlying causes are still unclear. The present study investigated details of gonadotrophin and progestogen secretion in pregnant mares (n = 11) with or without experimentally reduced early postovulatory luteal function. From days 0 to 3 after ovulation, they were treated with the prostaglandin F (PGF) analogue cloprostenol or left untreated. After conceptus collection on day 34, they were assigned to the opposite treatment. Mares were affiliated to the group primary corpus luteum (n = 6) or diestrous corpus luteum (n = 5) depending on diestrous corpus luteum (CL) detection in the PGF pregnancy. For statistical comparisons, a -value < 0.05 was significant. There was an effect of treatment ( < 0.01), but not of group on progestogen concentration. The concentration of LH was higher in PGF-treated than in untreated pregnancies ( < 0.05), but did not differ between groups. The FSH concentration did not differ between groups nor treatments. The total luteal tissue area was greater in mares with a diestrous ovulation during the PGF treatment pregnancy. Low progestogen concentration in the early postovulatory phase diminish the negative feedback on the hypothalamic-pituitary axis in early pregnancy and, thus, stimulate a luteal tissue response. Detection of secondary CL at the time of pregnancy examination in mares may reflect that early post-ovulatory progestogen concentrations were low.
马的黄体期自发性延长已有报道，但潜在原因仍不清楚。本研究调查了有或无实验性降低排卵后早期黄体功能的怀孕母马（n = 11）中促性腺激素和孕激素分泌的细节。在排卵后的第0至3天，给它们注射前列腺素F（PGF）类似物氯前列醇或不进行治疗。在第34天收集胚胎后，将它们分配到相反的治疗组。根据PGF处理的怀孕母马中黄体期黄体（CL）的检测情况，母马被分为原发性黄体组（n = 6）或动情期黄体组（n = 5）。为进行统计学比较，P值<0.05具有显著性。治疗对孕激素浓度有影响（P<0.01），但组间无影响。接受PGF治疗的怀孕母马中促黄体生成素（LH）的浓度高于未治疗的怀孕母马（P<0.05），但组间无差异。促卵泡生成素（FSH）浓度在组间和治疗组之间均无差异。在PGF处理的怀孕母马中，动情期排卵的母马黄体组织总面积更大。排卵后早期孕激素浓度低会减弱妊娠早期下丘脑 - 垂体轴的负反馈，从而刺激黄体组织反应。母马妊娠检查时检测到继发性黄体可能反映排卵后早期孕激素浓度较低。
