Axons containing the growth associated protein GAP-43 specifically target rat corticotrophs following adrenalectomy.
Axons containing the growth associated protein GAP-43 specifically target rat corticotrophs following adrenalectomy.
复制标题
含有生长相关蛋白 GAP-43 的轴突专门针对肾上腺切除术后的大鼠促肾上腺皮质激素。
DOI：
10.1046/j.1365-2826.1998.00252.x
复制
发表时间：
1998
影响因子：
3.2
通讯作者：
Kuhl,JM
中科院分区：
文献类型：
--
作者：
Paden,CM;Babcock,C;Conner,KA;Duong,DK;Kuhl,JM
大鼠垂体前叶（AP）内存在广泛的神经纤维网络，对神经元生长相关蛋白GAP-43（GAP-43-IR）具有免疫反应性，据报道，肾上腺切除术（ADX）后4天，这些纤维的密度增加。在本研究中，我们采用共聚焦双标记免疫荧光显微镜来确定GAP-43-IR纤维是否在ADX后的不同时间段与促肾上腺皮质激素细胞特异性相关。在ADX后4天，GAP-43-IR的密度明显增加，并且这种增加在ADX后7天和14天持续。与GAP-43-IR轴突明显接触的促肾上腺皮质激素细胞的百分比在ADX后4天为87%，在14天为92%。此外，在任一组中，少于15%的GAP-43-IR终末与除促肾上腺皮质激素细胞以外的细胞相关。在促肾上腺皮质激素细胞经历肥大和增生的时期期间，这些细胞的这种高度特异性靶向表明轴突发芽响应于ADX而发生。虽然完整大鼠AP中较低强度的GAP-43-IR排除了精确的定量分析，但这些动物中大多数促肾上腺皮质激素细胞似乎也被选择性神经支配。GAP-43-IR轴突选择性地接触促肾上腺皮质激素细胞，并且在ADX后GAP-43-IR轴突的靶向生长维持了神经支配的特异性和彻底性，这些观察结果强烈表明这些纤维具有功能意义。
An extensive network of nerve fibers immunoreactive for the neuronal growth associated protein GAP‐43 (GAP‐43‐IR) is present within the anterior pituitary (AP) of the rat, and the density of these fibers has been reported to increase 4 days after adrenalectomy (ADX). In the present study, we employed confocal dual‐label immunofluorescence microscopy to determine whether GAP‐43‐IR fibers are specifically associated with corticotrophs at various intervals after ADX. A dramatic increase in the density of GAP‐43‐IR was apparent 4 days after ADX, and this increase was sustained at 7 and 14 days post‐ADX. The percentage of corticotrophs in apparent contact with GAP‐43‐IR axons was 87% at 4 days after ADX and 92% at 14 days. In addition, fewer than 15% of GAP‐43‐IR terminals were associated with cells other than corticotrophs in either group. This highly specific targeting of corticotrophs during a period in which these cells are undergoing both hypertrophy and hyperplasia indicates that axonal sprouting is occurring in response to ADX. While the less intense GAP‐43‐IR in the AP of intact rats precluded precise quantitative analysis, the majority of corticotrophs also appeared to be selectively innervated in these animals. The observations that GAP‐43‐IR axons selectively contact corticotrophs, and that both the specificity and thoroughness of innervation are maintained by targeted growth of GAP‐43‐IR axons following ADX, strongly suggest that these fibers are of functional significance.