Madaus S, Schusdziarra V, Seufferlein T, Classen M
Department of Internal Medicine II, Technical University of Munich, Germany.
Life Sci. 1988;42(23):2381-7. doi: 10.1016/0024-3205(88)90192-0.
Galanin has been shown to be present in the gastrointestinal tract, pancreas and CNS. In the rat stomach, immunohistochemical studies have revealed the presence of galanin in the intrinsic nervous system suggesting a function as putative neurotransmitter or neuromodulator which could affect neighbouring exo- or endocrine cells. Therefore this study was performed to determine the effect of galanin on the secretion of gastrin and somatostatin-like immunoreactivity (SLI) from the isolated perfused rat stomach. The stomach was perfused via the celiac artery and the venous effluent was collected from the portal vein. The luminal content was kept at pH 2 or 7 Galanin at a concentration of 10(-10), 10(-9) and 10(-8) M inhibited basal gastrin release by 60-70% (60-100 pg/min; p less than 0.05) at luminal pH 7. At luminal pH 2 higher concentrations of galanin (10(-9) and 10(-8) M) decreased basal gastrin secretion by 60-70% (60-100 pg/min; p less than 0.05). This inhibitory effect was also present during infusion of neuromedin-C, a mammalian bombesin-like peptide that stimulates gastrin release. SLI secretion remained unchanged during galanin administration. The inhibitory action of galanin on gastrin secretion was also present during the infusion of tetrodotoxin suggesting that this effect is not mediated via neural pathways. The present data demonstrate that galanin is an inhibitor of basal and stimulated gastrin secretion and has to be considered as an inhibitory neurotransmitter which could participate in the regulation of gastric G-cell function.
甘丙肽已被证明存在于胃肠道、胰腺和中枢神经系统中。在大鼠胃中，免疫组织化学研究显示，内在神经系统中存在甘丙肽，这表明它可能作为一种假定的神经递质或神经调节剂发挥作用，进而影响邻近的外分泌或内分泌细胞。因此，进行本研究以确定甘丙肽对离体灌注大鼠胃中胃泌素分泌和生长抑素样免疫反应性（SLI）的影响。胃通过腹腔动脉进行灌注，静脉流出液从门静脉收集。管腔内容物的pH值保持在2或7。在管腔pH值为7时，浓度为10^(-10)、10^(-9)和10^(-8) M的甘丙肽可使基础胃泌素释放减少60 - 70%（60 - 100 pg/min；p < 0.05）。在管腔pH值为2时，较高浓度的甘丙肽（10^(-9)和10^(-8) M）可使基础胃泌素分泌减少60 - 70%（60 - 100 pg/min；p < 0.05）。在输注神经介素C（一种刺激胃泌素释放的哺乳动物铃蟾肽样肽）期间，这种抑制作用也存在。在给予甘丙肽期间，SLI分泌保持不变。在输注河豚毒素期间，甘丙肽对胃泌素分泌的抑制作用也存在，这表明这种作用不是通过神经途径介导的。目前的数据表明，甘丙肽是基础和刺激状态下胃泌素分泌的抑制剂，必须被视为一种抑制性神经递质，它可能参与胃G细胞功能的调节。
