褪黑素对吗啡戒断大鼠海马神经细胞内游离钙和钙调蛋白的影响

Effects of melatonin on intracellular free calcium and CaM of nerve cells in hippocampus of morphine withdrawal rats

目的 探讨褪黑素对吗啡戒断大鼠海马神经细胞内游离钙 ( [Ca2 +]i)和钙调蛋白 (CaM)的影响。方法 以剂量递增法连续 5d皮下注射吗啡成瘾模型。用流式细胞术测定海马神经细胞内游离钙和钙调蛋白活性。结果 ①与对照组比较 ,吗啡成瘾大鼠海马神经细胞内游离钙含量和钙调蛋白活性明显升高 (P <0 0 1)。纳洛酮催促戒断后细胞内游离钙含量迅速下降 (P <0 0 1) ,但钙调蛋白相对活性无显著变化 (P >0 0 5 )。②与纳洛酮催促组比较 ,褪黑素可以抑制吗啡戒断大鼠海马神经细胞内CaM活性和游离钙含量的迅速下降 (P <0 0 5 )。结论 吗啡成瘾及戒断直接影响大鼠海马神经细胞内游离钙含量和钙调蛋白活性。

Objective To explore the effects of melatonin on intracellular free calcium ([Ca 2+ ]i) and calmodulin (CaM) of nerve cells in hippocampus of morphine withdrawal rats Methods Morphine addiction model in rats was induced by subcutaneous injection of morphine in daily increasing doses for 5 days The [Ca 2+ ]i and CaM activity in hippocampus was assayed with flow cytometry Results ① Compared with control group,morphine addiction significantly increased the [Ca 2+ ]i and CaM activity of nerve cells in hippocampus( P <0 01) Following naloxone precipitation,[Ca 2+ ]i rapidly decreased ( P <0 01),there were no significant changes in the CaM activity (P>0 05) ②Compared with naloxone group,rapid drop of [Ca 2+ ]i and CaM activity in hippocampus of the morphine withdrawal rats were significantly inhibited by ip MT ( P <0 05) Conclusions The morphine addiction and withdrawal may involve [Ca 2+ ]i contents and CaM activity of nerve cells in hippocampus The mechanism of the inhibitory effect of melatonin on abstinence syndrome of morphine dependent rats may be related to the regulation of [Ca 2+ ]i contents and CaM activity of nerve cells in hippocampus