Jordan V, Dieguez C, Lafaffian I, Rodriguez-Arnao M D, Gomez-Pan A, Hall R, Scanlon M F
Clin Endocrinol (Oxf). 1986 Mar;24(3):291-8. doi: 10.1111/j.1365-2265.1986.tb03270.x.
In order to establish the influence of dopaminergic, alpha-adrenergic and cholinergic pathways on GRF-mediated GH release we have studied the GH responses to GRF 1-29 (100 or 50 micrograms as i.v. bolus) alone and in combination with metoclopramide (MCP, 10 mg, i.v.), thymoxamine (THYM, 210 micrograms/min, 150 min infusion), and atropine (1.2 mg, i.v.). We have also investigated any possible interaction between TRH and GRF in view of the reported inhibitory effects of TRH infusion on stimulated GH release. Dopaminergic and alpha-adrenergic blockade with MCP and THYM respectively, did not have any effect on the GH responses to GRF. This lack of effect strongly suggests that any action which these neurotransmitters may exert on GH secretion is not at a pituitary level. TRH did not modify the GH response to GRF suggesting that the inhibitory effect on stimulated GH secretion is exerted at a hypothalamic level. In contrast, GH responses to GRF were significantly reduced by prior administration of atropine. These data support the view that cholinergic pathways play an important role in the regulation of GH secretion and such control may be exerted at both hypothalamic and pituitary levels.
为了确定多巴胺能、α-肾上腺素能和胆碱能途径对生长激素释放因子（GRF）介导的生长激素（GH）释放的影响，我们研究了单独给予GRF 1-29（静脉推注100或50微克）以及联合给予甲氧氯普胺（MCP，10毫克，静脉注射）、百里胺（THYM，210微克/分钟，输注150分钟）和阿托品（1.2毫克，静脉注射）时的GH反应。鉴于有报道称输注促甲状腺激素释放激素（TRH）对刺激的GH释放有抑制作用，我们还研究了TRH与GRF之间可能存在的相互作用。分别用MCP和THYM阻断多巴胺能和α-肾上腺素能，对GH对GRF的反应没有任何影响。这种无效应强烈表明，这些神经递质可能对GH分泌产生的任何作用并非在垂体水平。TRH并未改变GH对GRF的反应，这表明对刺激的GH分泌的抑制作用是在下丘脑水平发挥的。相反，预先给予阿托品可显著降低GH对GRF的反应。这些数据支持这样一种观点，即胆碱能途径在GH分泌的调节中起重要作用，并且这种调节可能在下丘脑和垂体水平均发挥作用。
