The Paul Mellon Laboratory of Equine Reproduction (formerly The Equine Fertility Unit), 3 Tower Stables, Cheveley Park, Newmarket, Suffolk, UK.
Equine Vet J. 2009 Sep;41(7):678-84. doi: 10.2746/042516409x429428.
Fillies completely devoid of endometrial glands (uterine gland knockout; UGKO) would make ideal experimental models in which to study the role of endometrial histotroph in embryogenesis and early fetal development in the mare.
Administration of a synthetic progestagen plus oestrogen to newborn filly foals and, thereafter, at regular intervals to age 6 months, would permanently suppress endometrial gland development.
Nine half-sister Thoroughbred filly foals were treated, in 3 groups, with: A) the weakly active progestagen, norgestomet, administered from birth to age 6 months, in subcutaneous implant form plus oestradiol valerate and norgestomet i.m. at fortnightly intervals; B) the strongly active oral progestagen, altrenogest, administered daily from birth to age 6 months plus fortnightly injections of oestradiol valerate and norgestomet; C) nothing (untreated controls). Endometrial biopsies were recovered from all fillies at ages 6 months and 2 years to assess the degree of endometrial gland morphogenesis and to determine immunohistochemically the presence or absence of oestrogen and progesterone receptors in the endometrial tissues.
Groups B and C showed no endometrial gland development, whereas Group A fillies showed a high degree of endometrial gland development, plus strong staining for both oestrogen and progesterone receptors at age 6 months. All 9 fillies showed full normal endometrial gland morphogenesis, development and function at age 2 years.
While the administration of a strongly active progestagen over-rode the actions of the concomitantly administered oestrogen and suppressed endometrial gland development during the period of administration, treatment with oestradiol valerate together with a weakly active progestagen, stimulated precocious endometrial gland development. Neither steroid was able to create the desired UGKO experimental model and all fillies showed normal endometrial gland development and fertility after puberty. Hence, ovarian oestrogen, not progesterone, appears to be the basic stimulus for endometrial gland morphogenesis in the horse.
完全缺乏子宫内膜腺体的小母马（子宫内膜腺敲除；UGKO）将成为研究马胚胎发生和早期胎儿发育中子宫内膜组织在胚胎发生和早期胎儿发育中的作用的理想实验模型。
向新生小母马驹和此后每隔 6 个月定期给予合成孕激素加雌激素治疗，将永久抑制子宫内膜腺的发育。
9 头半姐妹纯血小母马驹分为 3 组，分别接受以下治疗：A）弱活性孕激素，norgestomet，从出生到 6 个月以皮下植入物形式给予，外加雌二醇戊酸酯和 norgestomet 每两周肌肉注射一次；B）强活性口服孕激素，altrenogest，从出生到 6 个月每天给予，外加每两周注射雌二醇戊酸酯和 norgestomet；C）无治疗（未治疗对照）。所有小母马驹在 6 个月和 2 岁时取子宫内膜活检，评估子宫内膜腺形态发生的程度，并通过免疫组织化学确定子宫内膜组织中雌激素和孕激素受体的存在或缺失。
B 组和 C 组均未出现子宫内膜腺发育，而 A 组小母马驹在 6 个月时表现出高度的子宫内膜腺发育，并且雌激素和孕激素受体染色强烈。所有 9 头小母马驹在 2 岁时均表现出正常的子宫内膜腺形态发生、发育和功能。
虽然给予强活性孕激素会抵消同时给予的雌激素的作用并抑制孕激素的作用在给药期间子宫内膜腺的发育，但用雌二醇戊酸酯与弱活性孕激素联合治疗会刺激早期子宫内膜腺的发育。这两种类固醇都不能创建所需的 UGKO 实验模型，所有小母马驹在青春期后均表现出正常的子宫内膜腺发育和生育能力。因此，卵巢雌激素而不是孕激素似乎是马子宫内膜腺形态发生的基本刺激物。
