Todd J F, Edwards C M, Ghatei M A, Bloom S R
Endocrine Unit, Imperial College of Science, Technology and Medicine Hammersmith Hospital, London W12 ONN, United Kingdom.
Am J Physiol Endocrinol Metab. 2000 Jun;278(6):E1060-6. doi: 10.1152/ajpendo.2000.278.6.E1060.
Intravenous injection of galanin increases plasma growth hormone (GH) and prolactin (PRL) concentrations. In the rat, the effects of galanin on GH appear to be mediated via the hypothalamic galanin receptor GAL-R(1), at which galanin-(3-29) is inactive. In contrast, the effect of galanin on PRL is mediated via the pituitary-specific galanin receptor GAL-R(W), at which galanin-(3-29) is fully active. We investigated the effects of an intravenous infusion of human galanin (hGAL)-(1-30) and -(3-30) on anterior pituitary hormone levels in healthy females. Subjects were infused with saline, hGAL-(1-30) (80 pmol. kg(-1). min(-1)), and hGAL-(3-30) (600 pmol. kg(-1). min(-1)) and with boluses of gonadotropin-releasing hormone, thyrotropin-releasing hormone, and growth hormone-releasing hormone (GHRH). Both hGAL-(1-30) and -(3-30) potentiated the rise in GHRH-stimulated GH levels [area under the curve (AUC), saline, 2,810 +/- 500 vs. hGAL-(1-30), 4,660 +/- 737, P < 0.01; vs. hGAL-(3-30), 6, 870 +/- 1,550 ng. min. ml(-1), P < 0.01]. In contrast to hGAL-(1-30), hGAL-(3-30) had no effect on basal GH levels (AUC, saline, -110 +/- 88 vs. hGAL 1-30, 960 +/- 280, P < 0.002; vs. hGAL-(3-30), 110 +/- 54 ng. min. ml(-1), P = not significant). These data suggest that the effects of galanin on basal and stimulated GH release are mediated via different receptor subtypes and that the human equivalent of GAL-R(W) may exist.
静脉注射甘丙肽可提高血浆生长激素（GH）和催乳素（PRL）的浓度。在大鼠中，甘丙肽对GH的作用似乎是通过下丘脑甘丙肽受体GAL-R(1)介导的，而甘丙肽-(3-29)对此受体无活性。相反，甘丙肽对PRL的作用是通过垂体特异性甘丙肽受体GAL-R(W)介导的，甘丙肽-(3-29)对此受体具有完全活性。我们研究了静脉输注人甘丙肽（hGAL）-(1-30)和-(3-30)对健康女性垂体前叶激素水平的影响。受试者分别接受生理盐水、hGAL-(1-30)（80 pmol·kg⁻¹·min⁻¹）、hGAL-(3-30)（600 pmol·kg⁻¹·min⁻¹）输注，并静脉推注促性腺激素释放激素、促甲状腺激素释放激素和生长激素释放激素（GHRH）。hGAL-(1-30)和-(3-30)均增强了GHRH刺激的GH水平升高[曲线下面积（AUC），生理盐水组为2,810±500，hGAL-(1-30)组为4,660±737，P<0.01；hGAL-(3-30)组为6,870±1,550 ng·min·ml⁻¹，P<0.01]。与hGAL-(1-30)不同，hGAL-(3-30)对基础GH水平无影响（AUC，生理盐水组为-110±88，hGAL 1-30组为960±280，P<0.002；hGAL-(3-30)组为110±54 ng·min·ml⁻¹，P=无显著性差异）。这些数据表明，甘丙肽对基础和刺激状态下GH释放的作用是通过不同的受体亚型介导的，并且可能存在与GAL-R(W)等效的人类受体。
