CONCENTRATION OF CYCLIC-AMP DURING THE MATURATION OF PIG OOCYTES IN-VIVO AND IN-VITRO
CONCENTRATION OF CYCLIC-AMP DURING THE MATURATION OF PIG OOCYTES IN-VIVO AND IN-VITRO
复制标题
DOI：
10.1530/jrf.0.1000403
复制
发表时间：
1994-03-01
期刊：
影响因子：
--
通讯作者：
SEREN, E
中科院分区：
文献类型：
--
作者：
MATTIOLI, M;GALEATI, G;SEREN, E
测定了猪卵母细胞在体内和体外成熟过程中胞内cAMP的浓度。用500 iu hCG对用孕马血清促性腺激素（PMSG）处理的后备母猪进行体内成熟诱导。虽然PMSG不影响cAMP浓度（基础值，每个卵母细胞1.69 +/- 0.28 fmol），但hCG诱导了瞬时升高（hCG注射后12小时，每个卵母细胞8.86 +/- 1.15 fmol）。同样，如果卵母细胞（是否被卵丘细胞包围）在LH存在下与卵泡壁共培养，则在体外成熟的卵母细胞中cAMP浓度升高。当裸露的卵母细胞与壁颗粒细胞共培养时，cAMP也得到了同样的增加。泡囊细胞仅表现出中等活性，而卵丘细胞完全无效。暴露于LH的颗粒细胞在培养24小时后失去了刺激作用。在FSH的存在下，卵母细胞产生的cAMP不受任何类型的卵泡细胞的影响。用双丁酰cAMP研究了cAMP在卵母细胞成熟控制中的作用。二丁酰cAMP的存在以剂量依赖性方式阻止减数分裂的恢复，但当它仅在培养的前12小时内存在时，减数分裂进程加速（培养24小时后，在用二丁酰cAMP处理的组和对照组中，分别有0和47%的卵母细胞具有萌发囊泡）。结果表明：（i）在减数分裂恢复之前，卵母细胞内cAMP浓度短暂增加;（ii）cAMP浓度的增加依赖于卵母细胞腺苷酸环化酶的刺激，可能是由LH处理的卵泡细胞产生的可溶性因子引起的;（iii）cAMP的增加可能局限于成熟的前10-20小时，这是由于LH处理的体细胞的刺激作用逐渐减弱;和（iv）在整个成熟过程中高浓度的cAMP维持减数分裂停滞，并且瞬时增加可促进减数分裂。
Intracellular concentrations of cyclic AMP (cAMP) were measured in pig oocytes maturing in vivo or in vitro. Maturation in vivo was induced with 500 iu hCG administered to gilts treated with pregnant mares' serum gonadotrophin (PMSG). Although PMSG did not affect cAMP concentrations (basal values, 1.69 +/- 0.28 fmol per oocyte), hCG induced a transient rise (8.86 +/- 1.15 fmol per oocyte 12 h after hCG injection). Similarly, the cAMP concentration rose in oocytes maturing in vitro if the oocytes (surrounded or not by cumulus cells) were co-cultured with the follicle wall in the presence of LH. The same increase in cAMP was obtained when denuded oocytes were co-cultured with mural granulosa cells. Theca cells exhibited only a moderate activity, while cumulus cells were totally ineffective. Granulosa cells exposed to LH lost their stimulating influence after 24 h of culture. In the presence of FSH, cAMP production by the oocyte was unaffected by any type of follicle cell. The role of cAMP in the control of oocyte maturation was investigated using dibutyryl cAMP. The presence of dibutyryl cAMP prevented the resumption of meiosis in a dose-dependent manner, but when it was present during the first 12 h of culture only, meiotic progression was accelerated (0 versus 47% of oocytes had germinal vesicles in groups treated with dibutyryl cAMP and control groups, respectively, after 24 h of culture). The results demonstrate that: (i) cAMP concentrations increase transiently in oocytes before the resumption of meiosis; (ii) increased concentrations of cAMP depend on the stimulation of oocyte adenylyl cyclase, possibly by a soluble factor produced by follicle cells exposed to LH; (iii) the increase in cAMP is probably confined to the first 10-20 h of maturation owing to the progressive reduction of the stimulating influence of LH-treated somatic cells; and (iv) a high concentration of cAMP throughout maturation maintains meiotic arrest and a transient increase may facilitate meiosis.