检索历史 清除

摘要免疫系统的重要成份——单核细胞和粒细胞，均来源于骨髓粒单系祖细胞（CFU-GM）。松果体能够通过昼夜节律性分泌褪黑激素（MT）而影响CFU-GM的增殖。本实验初步探讨其作用机制，发现CFU-GM的增殖呈昼夜节律性，高峰在夜间0点；改变光照条件，则CFU-GM也随之改变：于持续黑暗时增高，持续光照时减低；MT体外对CFU-GM未见有促进作用，考虑MT可能通过中间环节而起作用。因此，我们将阿片受体阻滞剂纳洛酮给小鼠皮下注射，结果发现CFU-GM的增殖明显受抑，提示松果体对CFU-GM的调节可能有内源性阿片肽参与。

abstractsIt has been suggested that the pineal gland as a neuroendocrine organ exerts an immunomodulatory effect through the circadian release of its main hormone melatonin. The present study was to further investigate the mechanisms mediating this effect. For this purpose progenitor cells for glanulocytes and monocytes (CFU-GM) were selected as main mmunological parameters. C57BL/6J mice were kept under controlled environmental lighting (12 h light/12 h dark) from 6:00 to 18:00. Bone marrow cells were harvested at 0:00, 6:00, 12:00 and 18:00 and assayed immediately for CFU-GM. It was observed that CFU-GM possessed a circadian rhythmicity with acrophase at 0:00, and the melatonin presented the highest concentration in serum at the same time. When mice were kept under persistent dark environment for 3 weeks, CFU-GM were prominently higher than the ones under persistent light environment. Administration of melatonin had no augmenting effects in vitro. These data suggest that variations of CFU-GM rely on the concentration of melatonin in serum and perhaps some intermatter might exist between melatonin and CFU-GM. We investigated the effect of naloxone, a specific opioid antagonist, on CFU--GM in vivo and found that naloxone can suppress CFU-GM at night. It means that melatonin might modulate CFU-GM through endogenous opioid system. As we know that endogenous opioid peptides are important neuropeptides in neuroimmunomodulation. Our finding points to a fundamental immunoregulatory role of circadian melatonin and to an activity of the neurohormone via opioid peptides.