Reimer M, Moller K, Sundler F, Hannibal J, Fahrenkrug J, Kanje M
Department of Animal Physiology, University of Lund, Sweden.
Neuroscience. 1999 Jan;88(1):213-22. doi: 10.1016/s0306-4522(98)00240-1.
The expression and axonal transport of pituitary adenylate cyclase-activating polypeptide (PACAP) was studied in the cultured vagus nerve of the rat by immunocytochemistry and in situ hybridization. The number of neurons immunoreactive for PACAP increased markedly within the nodose ganglion during a 24-48 h culture period, as did the number of cells containing messenger RNA for PACAP. PACAP was found to be axonally transported and accumulated at the site of a crush injury. The peptide was also released at this site. Addition of PACAP to regenerating nerves in culture did not affect axonal outgrowth, neither did antibodies against PACAP. Separate experiments showed that neither PACAP-27 nor PACAP-38 affected proliferation of non-neuronal cells measured as the incorporation of [3H]thymidine. In contrast, forskolin, another potent stimulator of adenylate cyclase besides PACAP, dramatically decreased [3H]thymidine incorporation. The results showed that, during regeneration of peripheral nerves, PACAP expression increases and the peptide is transported into the regenerating nerve, where it is released. The functional significance of this release is unknown, but it does not seem to be directly related to the initiation of proliferation of Schwann cells or initial axonal outgrowth.
通过免疫细胞化学和原位杂交技术，在大鼠培养的迷走神经中研究了垂体腺苷酸环化酶激活多肽（PACAP）的表达及轴突运输。在24 - 48小时的培养期内，结状神经节中对PACAP免疫反应阳性的神经元数量显著增加，含有PACAP信使核糖核酸的细胞数量也显著增加。发现PACAP通过轴突运输并在挤压伤部位积聚。该肽也在此部位释放。在培养的再生神经中添加PACAP不影响轴突生长，抗PACAP抗体也不影响。单独的实验表明，PACAP - 27和PACAP - 38均不影响以[3H]胸苷掺入量衡量的非神经元细胞增殖。相比之下，除PACAP外另一种有效的腺苷酸环化酶刺激剂福司可林显著降低了[3H]胸苷掺入量。结果表明，在周围神经再生过程中，PACAP表达增加且该肽被运输到再生神经中并在其中释放。这种释放的功能意义尚不清楚，但似乎与雪旺细胞增殖的起始或初始轴突生长没有直接关系。
