Foldes A, Hoskinson R M, Scaramuzzi R J, Hinks N T, Maxwell C A
Neuroendocrinology. 1983 Nov;37(5):378-85. doi: 10.1159/000123578.
The effects of active immunization against a range of gonadal steroids on pineal beta-adrenoceptors were studied in cycling Merino ewes. In selected cases, the effects of exogenous steroids were also investigated. Immunization against progesterone had no detectable effect on pineal beta-adrenoceptor density or ligand binding affinity. Immunization against estrone or 17 beta-estradiol significantly increased binding affinity and decreased beta-receptor density. Testosterone immunization in ewes caused similar effects but to a lesser degree. In contrast, immunization against androstenedione resulted in a decreased affinity and an increase in receptor density in ewes. In subsequent experiments, some parameters of pineal function in intact cycling and ovariectomized ewes were compared; a significant decrease in beta-receptor density and an increase in binding affinity were noted in the ovariectomized animals. Androstenedione-releasing implants decreased beta-receptor density and increased beta-receptor affinity in pineals from intact ewes, but these implants had no effect on pineal parameters in ovariectomized ewes. Immunization of ewes against 17 beta-estradiol had no significant effects on basal or isoprenaline-stimulated N-acetyltransferase or adenyl cyclase activities. Immunization of ewes against melatonin, or in vitro incubation of pineal glands with the hormone had no effects on the pineal parameters studied. It is concluded that estrogens affect the pinealocyte beta-receptors in ewes, while specific androgens may act indirectly on these receptors to modify their interaction with estrogens.
在发情期的美利奴母羊中，研究了针对一系列性腺类固醇进行主动免疫对松果体β-肾上腺素能受体的影响。在特定情况下，还研究了外源性类固醇的作用。针对孕酮进行免疫对松果体β-肾上腺素能受体密度或配体结合亲和力没有可检测到的影响。针对雌酮或17β-雌二醇进行免疫显著增加了结合亲和力并降低了β-受体密度。对母羊进行睾酮免疫也产生了类似的效果，但程度较轻。相比之下，针对雄烯二酮进行免疫导致母羊的亲和力降低和受体密度增加。在随后的实验中，比较了完整发情期和去卵巢母羊松果体功能的一些参数；在去卵巢动物中，观察到β-受体密度显著降低，结合亲和力增加。植入释放雄烯二酮的植入物降低了完整母羊松果体中的β-受体密度并增加了β-受体亲和力，但这些植入物对去卵巢母羊的松果体参数没有影响。对母羊进行17β-雌二醇免疫对基础或异丙肾上腺素刺激的N-乙酰转移酶或腺苷酸环化酶活性没有显著影响。对母羊进行褪黑素免疫，或在体外将松果体与该激素一起孵育，对所研究的松果体参数没有影响。得出的结论是，雌激素影响母羊的松果体细胞β-受体，而特定的雄激素可能间接作用于这些受体，以改变它们与雌激素的相互作用。
