Tang B Y, Adams N R
J Endocrinol. 1978 Aug;78(2):171-7. doi: 10.1677/joe.0.0780171.
The binding of [3H]oestradiol-17beta to the hypothalamus and pituitary gland of clover-affected permanently infertile and control ovariectomized ewes was compared in vivo and in vitro. When [3H]oestradiol-17beta was infused into the carotid artery (10 ng/min), the total homogenate and the nuclear and protamine-precipitable cytosol fractions of hypothalami and pituitary glands from clover-affected ewes bound significantly more[3H]oestradiol than those of the controls. Cytoplasmic oestradiol-17beta receptors from the pituitary glands of clover-affected ewes showed a significantly lower apparent association constant and a higher number of binding sites/mg protein in vitro. It is suggested that the hypothalami and pituitary glands of ewes made permanently infertile by oestrogenic clover are less sensitive to feedback regulation of oestradiol-17beta at physiological levels.
在体内和体外比较了[3H]雌二醇-17β与受三叶草影响的永久性不育母羊及对照去卵巢母羊的下丘脑和垂体的结合情况。当将[3H]雌二醇-17β以10纳克/分钟的速度注入颈动脉时，受三叶草影响的母羊下丘脑和垂体的总匀浆、核及鱼精蛋白可沉淀细胞溶质部分结合的[3H]雌二醇明显多于对照组。受三叶草影响的母羊垂体的细胞质雌二醇-17β受体在体外显示出明显较低的表观缔合常数和较高的每毫克蛋白结合位点数。提示因含雌激素的三叶草而永久性不育的母羊的下丘脑和垂体对生理水平的雌二醇-17β的反馈调节敏感性较低。
