The porcine ovarian follicle: III. Development of chorionic gonadotropin receptors associated with increase in adenyl cyclase activity during follicle maturation.
The porcine ovarian follicle: III. Development of chorionic gonadotropin receptors associated with increase in adenyl cyclase activity during follicle maturation.
复制标题
猪卵巢卵泡：III．
作者：
C. Y. Lee
已经研究了人绒毛膜促性腺激素 (hCG) 和小 (1-2 mm)、中 (3-5 mm) 和大 (6-12 mm) 猪卵巢卵泡颗粒细胞的 hCG 敏感腺苷酸环化酶的特异性结合。每个细胞的 hCG 结合位点数量 (n) 在卵泡成熟过程中增加，但结合亲和力没有变化。小滤泡细胞的 n 值为 300-400，中滤泡细胞的 n 值为 1,000-1,600，大滤泡细胞的 n 值为 8,200-10,000。所有细胞的解离常数均为 2.4 X 10(-10)M。 hCG 敏感的腺苷酸环化酶在猪颗粒细胞中得到证实。在卵泡发育过程中，颗粒细胞的腺苷酸环化酶系统对 hCG 刺激的反应越来越敏感。对于小、中和大滤泡细胞，hCG (1 mug/ml) 最大腺苷酸环化酶激活分别为 240、750 和 7,000 个环 AMP 分子/秒/细胞。对于大和中型卵泡细胞，给予半最大刺激的 hCG 浓度（1.0 X 10(-9)M）相似。结论是：1) 在猪卵巢卵泡成熟过程中，每个细胞的 hCG 受体位点增加，而结合亲和力没有变化；2) hCG 受体数量的增加与卵泡发育过程中 hCG 敏感的腺苷酸环化酶活性密切相关。
Specific binding of human chorionic gonadotropin (hCG), and the hCG-sensitive adenyl cyclase of granulosa cells from small (1-2 mm), medium (3-5 mm), and large (6-12 mm) porcine ovarian follicles have been studied. The number of hCG-binding sites per cell (n) increases during follicle maturation without a change in the binding affinity. The values for n were 300-400 for small, 1,000-1,600 for medium, and 8,200-10,000 for large-follicle cells. The dissociation constant is 2.4 X 10(-10)M for all cells. hCG-sensitive adenyl cyclase was demonstrated in porcine granulosa cells. The adenyl cyclase system of granulosa cells becomes increasingly responsive to hCG stimulation during follicle development. Maximal adenyl cyclase activation by hCG (1 mug/ml) was 240, 750, and 7,000 molecules of cyclic AMP formed/sec/cell, respectively, for small, medium, and large follicle cell. The concentration of hCG giving half-maximal stimulation (1.0 X 10(-9)M) was similar for both large and medium follicle cells. It is concluded that: 1) an increase in hCG receptor sites per cell occurs during maturation of the porcine ovarian follicle without change of binding affinity, and 2) the increase in the number of hCG receptors correlates well with hCG-sensitive adenyl cyclase activity during follicle development.