Quilliam L A, Dobson P R, Brown B L
Biochem Biophys Res Commun. 1985 Jun 28;129(3):898-903. doi: 10.1016/0006-291x(85)91976-x.
4 beta phorbol-12, 13-dibutyrate (PDBu) stimulated cyclic AMP accumulation in GH3 pituitary tumour cells in the presence of isobutylmethylxanthine. This effect persisted after preincubation of cells with cholera or pertussis toxins. In contrast, vasoactive intestinal polypeptide (VIP)-stimulated cyclic AMP accumulation was inhibited by PDBu in a dose dependent fashion (IC50 = 5.1 nM). Thyroliberin (TRH) had a similar, but non-additive, stimulatory effect on cyclic AMP accumulation with PDBu, however it did not inhibit VIP stimulation. These results suggest that TRH may stimulate cyclic AMP accumulation through protein kinase C and that stimulation of adenylate cyclase by PDBu and TRH may occur distal to the guanine nucleotide binding regulatory proteins, Ns and Ni.
在异丁基甲基黄嘌呤存在的情况下，4-β-佛波醇-12,13-二丁酸酯（PDBu）刺激了GH3垂体肿瘤细胞中环磷酸腺苷（cAMP）的积累。在用霍乱毒素或百日咳毒素对细胞进行预孵育后，这种效应仍然存在。相反，血管活性肠肽（VIP）刺激的cAMP积累以剂量依赖性方式被PDBu抑制（IC50 = 5.1 nM）。促甲状腺素释放激素（TRH）对cAMP积累与PDBu有类似但非相加的刺激作用，然而它并不抑制VIP刺激。这些结果表明，TRH可能通过蛋白激酶C刺激cAMP积累，并且PDBu和TRH对腺苷酸环化酶的刺激可能发生在鸟嘌呤核苷酸结合调节蛋白Ns和Ni的远端。
