Dix C J, Habberfield A D, Cooke B A
Biochem J. 1987 Apr 15;243(2):373-7. doi: 10.1042/bj2430373.
The phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) was shown to mimic luteinizing hormone (LH; lutropin) in causing desensitization of LH-mediated cyclic AMP production in tumour Leydig cells. However, there were differences between LH- and TPA-induced desensitization: (1) TPA induced a more rapid effect than LH; (2) adenosine did not inhibit TPA-induced desensitization, whereas it completely inhibited the LH-induced desensitization; (3) adenylate cyclase activity in plasma membranes from TPA-desensitized cells was not decreased, whereas similar preparations from LH-desensitized cells lost their response to LH and to LH plus guanosine 5'-[beta gamma-imido]triphosphate; TPA-, but not LH-, treated cells had a decreased capacity to respond to cholera toxin and forskolin. These results indicate that LH and phorbol esters induce desensitization of adenylate cyclase in rat tumour Leydig cells by different mechanisms.
佛波酯12 - O -十四烷酰佛波醇13 - 乙酸酯（TPA）已被证明可模拟促黄体生成素（LH；促性腺激素），使肿瘤间质细胞中LH介导的环磷酸腺苷（cAMP）生成发生脱敏。然而，LH诱导的脱敏和TPA诱导的脱敏之间存在差异：（1）TPA诱导的效应比LH更快；（2）腺苷不抑制TPA诱导的脱敏，而它完全抑制LH诱导的脱敏；（3）TPA脱敏细胞的质膜中腺苷酸环化酶活性没有降低，而LH脱敏细胞的类似制剂失去了对LH以及对LH加鸟苷5'-[βγ-亚氨基]三磷酸的反应；用TPA而非LH处理的细胞对霍乱毒素和福斯高林的反应能力降低。这些结果表明，LH和佛波酯通过不同机制诱导大鼠肿瘤间质细胞中腺苷酸环化酶的脱敏。
