褪黑激素对小鼠脑细胞内游离钙浓度的抑制作用

目的 研究褪黑激素（Ｍｅｌ）对老年小鼠大脑皮层突触体内钙含量以及激动剂动诱发的新生小鼠脑细胞（Ｃａ＾２＋）升高的影响，以探讨Ｍｅｌ抗衰老的作用机理。方法 钙离子荧光染料Ｆｕｒａ－２ＡＭ负载已制备的突触体或细胞，ＲＦ－５０００型双波长荧光分光光度计测定（Ｃａ＾２＋）ｉ，结果：长期使用Ｍｅｌ抑制老年小鼠大脑皮层Ｃａ＾２＋超负荷，Ｍｅｌ也降低钙通道激活剂Ｂａｙ－Ｋ８６４４，高浓度氯化钾（ＫＣｌ）和谷氨酸

Inhibitory effects of melatonin on free intracellular calcium in mouse brain cells.

AIM: To study the effects of melatonin (Mel) on cortical intrasynaptosomal calcium concentration in old mice and on Ca2+]i elevation induced by Bay-K-8644, KCl, and sodium l-glutamate in isolated brain cells of neonatal mouse, and to determine the antiaging mechanism of Mel. METHODS: Ca2+]i was measured in an RF-5000 recording spectrofluorophotometer by preloading the synaptosomes or cells with Fura 2-AM. RESULTS: Long term of administrating Mel inhibited the overload of Ca2+]i in old mouse cerebral cortex. The Ca2+]i in both high (20 mg.L-1) and low dose (1 mg.L-1) of Mel groups was reduced from (434 +/- 32) nmol. L-1 (the older control group) to (330 +/- 41) and (313 +/- 56) nmol.L-1, respectively, P < 0.01. Mel 0.01, 0.1, 1, and 3 mumol.L-1 remarkably reduced Ca2+]i elevations in isolated newborn mouse brain cells induced by Bay-K-8644, KCl, and Glu. CONCLUSIONS: The inhibitory effect of Mel on neuronal Ca2+]i overload is involved in its antiaging effect.