Zagon I S, McLaughlin P J
Brain Res. 1987 May 26;412(1):68-72. doi: 10.1016/0006-8993(87)91440-5.
The role of endogenous opioid systems in modulating the proliferation of developing cerebellar cells was examined autoradiographically in 6-day-old rats. The blockade of endogenous opioid-opioid receptor interaction by naltrexone, a potent opioid antagonist, was accompanied within 1-2 h by an increased proportion of cells incorporating [3H]thymidine. When high doses of naltrexone (50 mg/kg) were administered this index was still elevated 12 h later; however, when low doses of naltrexone (1 mg/kg) were administered the index of labeled cells was decreased markedly. Injection of methionine-enkephalin, an endogenous opioid peptide, also resulted in a decrease in the proportion of cells incorporating [3H]thymidine. Concomitant injection of 1 mg/kg naloxone, however, blocked the inhibitory effects of methionine-enkephalin on cell division but did not itself affect cell generation. These studies demonstrate that endogenous opioid systems can regulate the proliferation of cell populations in the developing nervous system and do so through an inhibitory mechanism.
利用放射自显影技术，在6日龄大鼠中研究了内源性阿片系统在调节发育中小脑细胞增殖方面的作用。强效阿片拮抗剂纳曲酮对内源性阿片-阿片受体相互作用的阻断，在1-2小时内伴随着掺入[3H]胸腺嘧啶核苷的细胞比例增加。给予高剂量纳曲酮（50mg/kg）时，该指标在12小时后仍升高；然而，给予低剂量纳曲酮（1mg/kg）时，标记细胞的指标显著下降。注射内源性阿片肽甲硫氨酸脑啡肽，也导致掺入[3H]胸腺嘧啶核苷的细胞比例降低。然而，同时注射1mg/kg纳洛酮可阻断甲硫氨酸脑啡肽对细胞分裂的抑制作用，但纳洛酮本身并不影响细胞生成。这些研究表明，内源性阿片系统可通过抑制机制调节发育中神经系统细胞群的增殖。
