PACAP mRNA在大鼠排卵过程中的表达与调节

Expression and regulation of PACAP mRNA during periovulation in the rat ovary

目的探讨垂体腺苷酸环化酶激活肽(pituitary adenylate cyclase-activating polypeptide,PACAP)mRNA在排卵过程中的表达情况与调节其表达的因素.方法采用RT-PCR对PACAP mRNA在使用外源性激素诱导的大鼠排卵过程中的表达变化进行研究,并在体外培养的排卵前卵泡颗粒细胞中分析了不同处理因素对其表达的影响.结果对预先用孕马血清(PMSG)处理的未成年大鼠给予hCG发现,给予hCG 4～12h期间,PACAP转录水平持续升高,其表达水平在给予hCG4h后达高峰.对体外培养的排卵前卵泡颗粒细胞的研究结果分析显示,与对照组相比hCG和hCG+PAF能提高颗粒细胞PACAP mRNA水平.结论 PACAP mRNA在排卵前卵泡呈瞬时性高表达,提示了PACAP可能在排卵过程中发挥重要作用.hCG能促进PACAP的转录,并且PAF可加强这种促进作用.

Objective To investigate the expression of PACAP mRNA during periovulation and the factors that regulate it. Methods We studied the changes of PACAP mRNA expression during periovulation in exogenous gonadotropin-induced ovaries of rat by RT-PCR, and furthermore analyzed the effect of different factors on granulosa cells of preovulatory follicles cultured in vitro. Results The expression of PACAP mRNA remained high from 4h to 12h after hCG treatment in the ovaries of PMSG-primed immature rats, reaching a maximum at 4 h. The result of cultured granulosa cells of preovulatory follicles in vitro showed that PACAP mRNA levels were elevated in the cells cultured with hCG and hCG ＋ PAF compared with control group. Conclusion Transient high levels of PACAP mRNA in preovulatory follicles suggest that PACAP may play an important rote during periovulation, hCG can induce PACAP transcripts and PAF can enhance it.