Nitric oxide synthase activity in rat gastric mucosa contributes to mucin synthesis elicited by calcitonin gene-related peptide
Nitric oxide synthase activity in rat gastric mucosa contributes to mucin synthesis elicited by calcitonin gene-related peptide
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DOI：
10.2220/biomedres.27.117
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发表时间：
2006-06-01
影响因子：
1.2
通讯作者：
Ishihara, Kazuhiko
中科院分区：
文献类型：
--
作者：
Ichikawa, Takafumi;Kusakabe, Tatsumi;Ishihara, Kazuhiko
胃内降钙素基因相关肽（calcitonin gene-related peptide，CGRP）的研究主要集中在胃粘膜下血流，而对胃粘膜上皮功能的研究较少。在这项研究中，我们研究了CGRP神经的年龄相关性变化及其对粘液代谢的影响。我们比较了CGRP在7周龄大鼠（年轻）和52周龄动物（中年）的胃粘膜中的免疫反应性。用青年和中年大鼠胃比较CGRP对粘蛋白生物合成的影响。测定胃体表层和深层粘膜一氧化氮合酶（NOS）活性。与青年大鼠相比，中年大鼠固有层和粘膜下层的CGRP神经纤维密度减少。CGRP刺激7周龄大鼠培养的粘膜体中粘蛋白的生物合成，但不刺激52周龄大鼠。与青年大鼠相比，中年大鼠胃粘膜表层总NOS活性明显降低。这些发现表明CGRP诱导的粘蛋白生物合成的年龄依赖性减少，以及在大鼠胃中的CGRP纤维的密度。老龄大鼠胃粘膜表层NOS活性降低也可能是CGRP对粘蛋白生物合成缺乏调节的主要原因。
The majority of research for the calcitonin gene-related peptide (CGRP) in the stomach has been devoted to the submucosal blood flow, and only slight attention has been paid to its involvement in the gastric epithelial function. In this study, we examined the age-related change in the CGRP-containing nerves and its effects on the mucus metabolism. We compared the immunoreactivity for CGRP in the gastric mucosa of 7-week-old rats (young) to that of 52-week-old animals (middle-aged). The effects of CGRP on the mucin biosynthesis were compared using the stomachs from both young and middle-aged rats. The nitric oxide synthase (NOS) activity was measured in the surface and deep mucosa of the gastric corpus. The density of the CGRP nerve fibers was reduced in both the lamina propria and submucosa of the middle-aged rats compared to the young rats. CGRP stimulated the mucin biosynthesis in the cultured corpus mucosa from the 7-week-old rats, but not from the 52-week-old rats. The total NOS activity of the surface layer in the corpus mucosa was markedly reduced in the middle-aged rats compared to the young rats. These findings demonstrate the age-dependent reduction in the CGRP-induced mucin biosynthesis, as well as in the density of the CGRP fibers in the rat stomach. The decreased NOS activity in the surface layer of the oxymic mucosa in the aged rats may also be a principal cause for the lack of regulation of the mucin biosynthesis by CGRP.