环磷酸腺苷参与哺乳动物卵泡发育的研究进展

Research progress of cyclic adenosine monophosphate in mammalian follicular development

环磷酸腺苷(cyclic adenosine monophosphate, cAMP)是哺乳动物体内重要且保守的第二信使之一,可通过转导细胞外信号参与调节多种器官和组织的发育及生理功能。已有研究显示,雌性哺乳动物卵母细胞减数分裂进程与cAMP的水平变化密切相关且受到严格调控。卵母细胞中cAMP主要由腺苷酸环化酶3 (adenylyl cyclase 3, AC3)合成,其降解则受磷酸二酯酶3A (phosphodiesterase 3A, PDE3A)调控,这两者共同协调卵母细胞cAMP水平,从而使其在雌性卵巢的卵泡发育和卵子发生过程中发挥关键性作用。研究证明,处于生长卵泡中的卵母细胞胞质内高水平的cAMP可维持卵母细胞第一次减数分裂长期处于阻滞状态,只有当cAMP的合成被下调或其被PDE3A降解时,卵母细胞才能恢复减数分裂并成熟。而新近的研究显示,cAMP在卵子发生的其他阶段也发挥着重要的生理功能。为了能更全面地了解cAMP参与哺乳动物配子发生的调节作用及机制,本文综述了近年来国内外cAMP调节哺乳动物卵泡发育的相关研究成果,以期为深入理解cAMP与生殖细胞发生、发育的关系提供参考。

Cyclic adenosine monophosphate(cAMP) is one of the significant and conserved second messengers in mammals, and it participates in regulating the developmental and physiological functions of various organs and tissues through transducting extracellular signals.Studies have shown that the process of meiosis in female mammalian oocytes is closely related to the level of cAMP and strictly regulated.In oocytes, cAMP is mainly synthesized by adenylate cyclase 3(AC3) and degraded by phosphodiesterase 3A(PDE3A), both of which jointly regulate the level of cAMP in oocytes and play important roles in the follicular development and oogenesis of female ovaries.It has been well illuminated that high level of cAMP in the cytoplasm of oocytes in growing follicles could maintain the arrest of the first meiotic of oocytes for a long time.The oocytes will resume meiosis and mature either when the synthesis of cAMP is down-regulated, or when cAMP is degraded by PDE3A.In recent years, the novo physiological functions of c AMP in oogenesis have been reported.To better understand the regulatory role and mechanism of cAMP in mammalian gametogenesis, this paper reviews the relevant research regarding the relationship between cAMP and germ cell development.