Johnson A L, Tilly J L
Department of Animal Sciences, Rutgers State University, New Brunswick, New Jersey 08903.
Biol Reprod. 1988 Mar;38(2):296-303. doi: 10.1095/biolreprod38.2.296.
Studies were conducted to evaluate the effects of vasoactive intestinal peptide (VIP) on steroidogenesis and plasminogen-activator (PA) activity in isolated granulosa cells of the largest preovulatory (F1) follicle of the hen. Vasoactive intestinal peptide, but not avian pancreatic polypeptide, the chicken VIP fragment (16-28) or the VIP congener, PHM-27, induced a dose-related increase in progesterone and androgen secretion, with an apparent median effective dose (ED50) of 5.9 X 10(-7) and 5.7 X 10(-7) M, respectively. The effects of VIP were, at least in part, mediated by the adenylyl cyclase system in that cotreatment of cells with VIP and the phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX), potentiated the steroidogenic effects. However, the time course of action for VIP on steroidogenesis was considerably slower than that for the gonadotropin, luteinizing hormone (LH), and this was attributed to a slower induction of cyclic adenosine 3',5'-monophosphate (cAMP) formation within granulosa cells. Finally, VIP was found to be a potent inhibitor of PA activity, and this inhibition was potentiated by coincubation of VIP with IBMX. We suggest that, in the hen, VIP has a direct and specific action on both steroidogenesis and PA activity, and that these actions are mediated, at least in part, by the adenylyl cyclase system. The comparatively slow induction of cAMP formation by VIP suggests that this peptide is involved in the control of cell differentiation and development rather than the ovulatory process.
开展了多项研究，以评估血管活性肠肽（VIP）对母鸡最大排卵前（F1）卵泡的分离颗粒细胞中类固醇生成及纤溶酶原激活物（PA）活性的影响。血管活性肠肽可诱导孕酮和雄激素分泌呈剂量依赖性增加，而禽胰多肽、鸡VIP片段（16 - 28）或VIP同类物PHM - 27则无此作用，其表观半数有效剂量（ED50）分别为5.9×10⁻⁷和5.7×10⁻⁷ M。VIP的作用至少部分是由腺苷酸环化酶系统介导的，因为用VIP和磷酸二酯酶抑制剂3 - 异丁基 - 1 - 甲基黄嘌呤（IBMX）共同处理细胞可增强类固醇生成效应。然而，VIP对类固醇生成的作用时间进程比对促性腺激素促黄体生成素（LH）的作用时间进程要慢得多，这归因于颗粒细胞内环状腺苷3',5'-单磷酸（cAMP）形成的诱导较慢。最后，发现VIP是PA活性的有效抑制剂，VIP与IBMX共同孵育可增强这种抑制作用。我们认为，在母鸡中，VIP对类固醇生成和PA活性都有直接且特异性的作用，并且这些作用至少部分是由腺苷酸环化酶系统介导的。VIP诱导cAMP形成相对较慢，这表明该肽参与细胞分化和发育的调控，而非排卵过程。
