垂体腺苷酸环化酶激活肽减轻谷氨酸对海马神经元的损伤并抑制胞内钙升高

对原代培养７～９ｄ的海马神经元给予谷氨酸处理，２４ｈ后，神经元的存活率降低。预先给予垂体腺苷酸环化酶激活肽（ＰＡＣＡＰ）能显著减少谷氨酸引起的海马神经元死亡。谷氨酸呈剂量依赖性增加海马神经元细胞内钙离子含量，ＰＡＣＡＰ能抑制谷氨酸引起的海马神经元细胞内钙离子浓度的升高，特异性ＰＡＣＡＰ Ⅰ型受体拮抗剂ＰＡＣＡＰ ６－３８能完全阻断ＰＡＣＡＰ减轻谷氨酸所致海马神经元损伤及降低谷氨酸所致神经元细胞内钙

Pituitary adenylate cyclase activating polypeptide ameliorates the damage and inhibits the increase of intracellular calcium concentration in cultured hippocampal neurons induced by glutamate

Hippocampal neurons cultured from 7 to 9 d in vitro were used to observe the effect of glutamate. Treatment of glutamate for 24 h greatly decreased neuronal survival and pretreatment with pituitary adenylate cyclase activating polypeptide (PACAP) significantly attenuated hippocampal neuron death induced by glutamate. Moreover, glutamate dose-dependently increased the intracellular calcium concentration in cultured hippocampal neurons, while PACAP inhibited the increase of intracellular calcium concentration induced by glutamate. PACAP 6-38, a specific PACAP type I receptor antagonist, completely inhibited the amelioration of glutamate induced death and the decrease of intracellular calcium concentration induced by PACAP in cultured hippocampal neurons. The data suggest that PACAP has a neuroprotective effect on the hippocampal neuronal damage induced by glutamate, which is related to an inhibition of glutamate-induced increase of intracellular calcium concentration and mediated by PACAP type I receptor.