蛙皮素样肽调控胰岛素分泌机制研究进展

哺乳动物蛙皮素样肽(BLP)主要包括胃泌素释放肽(GRP)、神经肽C(NMC)和神经肽B(NMB),主要通过GRP-R和NMB-R 2种受体亚型介导生物学效应。其受体BRS-3的内源性配体尚未发现。BLP已经被证明具有促进胰岛素分泌的作用。从组织定位来看,BLP及其受体在胰腺均有分布,其调控胰岛素的分泌主要通过GRP-R介导,其效能与动物的种属、血糖和能量水平有关。BLP可能作为胰腺内神经递质直接促进胰岛β细胞或间接通过激活副交感神经促进胰岛素分泌。BLP还可激活三磷酸肌醇等途径,增加胞外Ca2+内流或者动员胞内钙库,促进胰岛素分泌。BLP对胰岛素分泌的研究不仅补充调控胰岛素分泌机制的理论,也为临床糖尿病的治疗提供新的思路。

Progress on Regulatory Mechanisms of Bombesin-like Peptides on Insulin Secretion

Mammalian bombesin-like peptides (BLPs)include gastrin-releasing peptide (GRP),neurome-din C (NMC)and neuromedin B (NMB).Two main receptor subtypes,the GRP-receptor and the NMB-receptor,mediate the biological functions of BLPs.BLPs and their receptors histologically localize in the pancreas.BLPs have been reported to stimulate the secretion of insulin mediated by the GRP-receptor.The efficiency of BLP on insulin secretion is affected by animal species,blood glucose level and energy level. BLPs may act as a neurotransmitter to directly stimulate pancreatic isletβ-cells,or indirectly activate the parasympathetic neuron to increase the secretion of insulin.Moreover,BLPs may activate the inositol triphosphate and promote the secretion of insulin when the cytosolic Ca2 + concentration increased through promoting extracellular Ca2 + influx and mobilization of intracellular calcium stores.The inositol triphos-phate pathway may mediate the BLPs-induced insulin secretion.Studies of BLPs on insulin secretion not only complement the theoretical mechanism of regulation of insulin secretion,but also provide a novel idea for clinical treatment of diabetes.