咖啡因引起离体大鼠脊髓降钙素基因相关肽释放

CAFFEINT CAUSED THE RELEASE OF CALCITONIN GENE-RELATED PEPTIDE FROM THE SLICES OF RAT SPINAL CORED IN VITRO

目的：探讨咖啡因是否可直接引起离体大鼠脊髓释放降钙素基因相关肽（Ｃａｌｃｉｔｏｎｉｎｇｅｎｅ－ｒｅｌａｔ－ｅｄｐｅｐｔｉｄｅ，ＣＧＲＰ）及其作用机制。方法：采用离体大鼠脊髓切片孵育，以放射免疫法则定ＣＧＲＰ的释放。结果：咖啡因（１～１０ｍｍｏｌ／Ｌ）浓度依赖性地引起大鼠脊髓ＣＧＲＰ释放。无钙液不影响加入咖啡因０～１０ｍｉｎ时ＣＧＲＰ的释放，但减少１０～２０ｍｉｎ时的ＣＧＲＰ释放。钌红或Ｒｙａｎｏｄｉｎｅ预孵育可分别抑制咖啡因引起的ＣＧＲＰ释放。结论：咖啡因通过激活细胞内对Ｒｙａｎｏｄｉｎｅ敏感的钙池钙离子释放，从而直接引起大鼠脊髓释放ＣＧＲＰ。

Objective:Effects of caffeine on the release of calcitonin gene-related peptide(CGRP)from rat spinal cord in vitro and its mechanism were determined.Methods:Spinal cord slices in rats and ra-dioimmunoassay of CGRP,Results:Caffeine(1～10 mmol/L)caused concentration-dependent release of CGRP from rat spinal cord in vitro. In the absence of calcium in the Krebs solution the effect of caf-feine was not changed at 0～10 min,but decreased at 10～20 min. Caffeine induced-CGRP release was inhibited by pretreatment with ruthenium red or ryanodine,respectively.Conclusion:The data sug-gested that caffeine directly evokes CGRP release by triggering calcium release from ryanodine-sensitive intracellular calcium store in rat spinal cord.