Adenylate cyclase of porcine granulosa cells: differential response to gonadotropins during follicle maturation.
Adenylate cyclase of porcine granulosa cells: differential response to gonadotropins during follicle maturation.
复制标题
猪颗粒细胞的腺苷酸环化酶：卵泡成熟过程中对促性腺激素的差异反应。
作者：
C. Y. Lee
本文研究了猪小（1-2 mm）、中（3-5 mm）和大（6- 1-2 mm）卵泡颗粒细胞中人FSH（hFSH）和人LH（hLH）/hCG介导的腺苷酸环化酶活性。小卵泡细胞的腺苷酸环化酶对hFSH高度敏感，比基础活性增加8至13倍，而hCG对酶活性的影响很小（仅增加2倍）。hFSH的刺激不能用hLH污染来解释，因为hFSH的刺激效应更大，半最大刺激的表观浓度（表观Km，370 ng/ml）低于hLH（表观Km，1700 ng/ml）。随着卵泡的发育，颗粒细胞的腺苷酸环化酶对hCG和hLH的反应性逐渐增强。饱和浓度的hCG刺激酶活性，在中等卵泡细胞中增加4倍，在大卵泡细胞中增加10- 14倍，而表观Km无变化。促黄体生成素的刺激作用类似于
The human FSH (hFSH)- and human LH (hLH)/hCG-mediated adenylate cyclase activities of granulosa cells from small (1–2 mm), medium (3–5 mm), and large (6–12 mm) porcine ovarian follicles were studied. The adenylate cyclase of small follicle cells was highly sensitive to hFSH with an 8- to 13-fold increase over the basal activity, whereas hCG had little effect (only a 2-fold increase) on the enzyme activity. The stimulation by hFSH cannot be accounted for by hLH contamination, since hFSH had a larger stimulatory effect and a lower apparent concentration for half-maximal stimulation (apparent Km, 370 ng/ml) than that of hLH (apparent Km, 1700 ng/ml). The adenylate cyclase of granulosa cells became increasingly responsive to hCG and hLH as the follicles developed. hCG at the saturating concentration stimulated the enzyme activity with a 4-fold increase in medium follicle cells and with a 10- to 14-fold increase in large follicle cells without change in the apparent Km. hLH had a stimulatory effect similar to ...