Effects of calcitonin gene-related peptide on the adenylate cyclase system in cultured rat skeletal muscle cells.
Effects of calcitonin gene-related peptide on the adenylate cyclase system in cultured rat skeletal muscle cells.
复制标题
降钙素基因相关肽对培养大鼠骨骼肌细胞腺苷酸环化酶系统的影响。
DOI：
10.1016/0024-3205(89)90058-1
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发表时间：
1989
期刊：
影响因子：
6.1
通讯作者：
Hiroshi Yoshida
中科院分区：
文献类型：
--
作者：
Kazuya Hashimoto;Shuji Uchida;Hiroshi Yoshida
从新生大鼠分离的骨骼肌细胞中，腺苷酸环化酶（AC）活性随着培养时间的增加而增加，表明存在异源超敏感性，就像体内去神经支配的情况一样。研究了在培养的骨骼肌细胞中添加降钙素生成肽（CGRP）对细胞AC活性的影响。CGRP （1 μM）作用24小时后，CGRP、异丙肾上腺素、NaF和forskolin刺激的AC活性升高均受到抑制，其中CGRP刺激的AC活性下降幅度最大。AC活性降低或增加的程度取决于CGRP浓度和暴露时间。CGRP刺激的AC活性在暴露于dbc-AMP 24小时后也有所下降。肌细胞暴露于CGRP 3天后，NaF、forskolin和CGRP刺激的AC活性无显著差异。这些结果表明，暴露于CGRP 1天主要引起CGRP受体的同源脱敏，而暴露于CGRP 3-4天引起AC催化单元的异源脱敏，可能是通过提高细胞中c-AMP的水平。这些结果提示位于运动神经末梢的CGRP可能作为骨骼肌的生理营养因子发挥作用。
Adenylate cyclase (AC) activity in skeletal muscle cells isolated from new born rats was increased with time in culture, indicating the presence of heterologous supersensitivity as in the case of denervation in vivo. The effect of addition of calcitonin generelated peptide (CGRP) to the cultures of skeletal muscle cells on increase in the AC activity was studied. The increases in AC activity stimulated by CGRP, isoproterenol, NaF and forskolin were depressed by exposure to CGRP (1 μM) for 24 hours, depression of CGRP-stimulated AC activity being the greatest. The extent of reduction in increase in AC activity depended on the concentration of CGRP and duration of exposure. The AC activity stimulated by CGRP was also decreased by exposure to dbc-AMP for 24 hours. When muscle cells were exposed to CGRP for 3 days, no significant difference among the AC activity stimulated by NaF, forskolin and CGRP was seen. These results suggest that exposure to CGRP for one day caused mainly homologous desensitization of the CGRP receptor, whereas exposure for 3–4 days caused heterologous desensitization of the AC catalytic unit, perhaps by elevating the c-AMP level in the cells. These results imply that CGRP, which is located in the motor nerve terminal, may play a role as a physiological trophic factor on skeletal muscle.