Martensz N D, Baird D T, Scaramuzzi R J, van Look P F
J Endocrinol. 1976 May;69(2):227-37. doi: 10.1677/joe.0.0690227.
Androstenedione and oestradiol were measured by radioimmunoassay in the utero-ovarian venous plasma of two ewes during anoestrus. The concentrations of both steroids were significantly higher than the corresponding concentrations in peripheral plasma, indicating that androstenedione and oestradiol are secreted by the ovary during anoestrus. The concentration of LH during anoestrus was measured by radioimmunoassay in jugular venous plasma of control ewes, ewes immunized against 11alpha-OH-androstenedione-bovine serum albumin and ewes that had been ovariectomized and hystrectomized 9 months previously. During a 12 h sampling period, discharges of LH occurred more frequently in the immunized ewes than in the control group but less frequently than in the ovariectomized group. The frequency of discharge was positively correlated with the titre of androstenedione antibodies in the immunized animals. After injection of 25 mug oestradiol benzoate (OB) all controls, 3 out of 5 immunized and 4 out of 5 ovariectomized-hysterectomized ewes showed positive feedback. No positive feedback occurred in the two ewes with the highest antibody titres to androstenedione, but negative feedback in response of OB apperaed to function normally in all the androstenedione immunized sheep. It is postulated that androstenedione, or one of its metabolites, normally modulates the effects of oestradiol in the control of gonadotrophin secretion in the ewe.
采用放射免疫分析法测定了两只处于乏情期母羊子宫 - 卵巢静脉血浆中的雄烯二酮和雌二醇。两种甾体激素的浓度均显著高于外周血浆中的相应浓度，表明雄烯二酮和雌二醇在乏情期由卵巢分泌。采用放射免疫分析法测定了对照组母羊、用11α - 羟基雄烯二酮 - 牛血清白蛋白免疫的母羊以及9个月前已切除卵巢和子宫的母羊颈静脉血浆中乏情期促黄体生成素（LH）的浓度。在12小时的采样期内，免疫母羊中LH的释放频率高于对照组，但低于卵巢切除组。释放频率与免疫动物体内雄烯二酮抗体的滴度呈正相关。注射25微克苯甲酸雌二醇（OB）后，所有对照组母羊、5只免疫母羊中的3只以及5只卵巢切除 - 子宫切除母羊中的4只均表现出正反馈。对雄烯二酮抗体滴度最高的两只母羊未出现正反馈，但在所有雄烯二酮免疫的绵羊中，OB引起的负反馈似乎正常发挥作用。据推测，雄烯二酮或其一种代谢产物通常在母羊促性腺激素分泌的控制中调节雌二醇的作用。
