Number, size, conduction, and vasoconstrictor ability of unmyelinated fibers of the ovarian nerve in adult and aged rats
Number, size, conduction, and vasoconstrictor ability of unmyelinated fibers of the ovarian nerve in adult and aged rats
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DOI：
10.1016/j.autneu.2011.05.001
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发表时间：
2011-10-28
影响因子：
2.7
通讯作者：
Aikawa, Yoshihiro
中科院分区：
文献类型：
--
作者：
Hanada, Tomoko;Uchida, Sae;Aikawa, Yoshihiro
本实验观察了年龄对成年（4-7月龄）和老年（28-31月龄）大鼠卵巢动脉旁卵巢神经无髓纤维的数量、大小、传导速度和血管收缩功能的影响。电镜形态学观察表明，卵巢神经主要含有无髓纤维，只有一个小的百分比（小于4%）的有髓纤维在任何年龄组。与成年大鼠（801 +/- 48）相比，老年大鼠（717 +/- 59）的无髓纤维数量趋于减少，尤其是直径较小的纤维，尽管该差异无统计学显著性。成年大鼠（1.05 +/- 0.04 m/s）和老年大鼠（1.02 +/- 0.05 m/s）卵巢神经内无髓纤维的最大传导速度相似。在麻醉下，电刺激的远端部分切断卵巢神经减少卵巢血流量，通过激光多普勒血流仪测量，当刺激强度高于阈值的无髓C纤维。在2-20 Hz频率下以超最大强度（10 V）刺激卵巢神经，在成年和老年大鼠中产生卵巢血流量的频率依赖性减少。成年和老年大鼠之间的卵巢神经的电刺激频率相当，卵巢血流减少的幅度没有显着差异。总的来说，这些数据表明，卵巢神经中的无髓C纤维的数量，大小，传导能力和血管收缩功能在老年大鼠保持。(C)2011 Elsevier B. V.保留所有权利。
The effect of aging on the number, size, conduction velocity, and vasoconstrictive function of unmyelinated fibers in ovarian nerve accompanying the ovarian artery was studied in adult (4-7 mo) and aged (28-31 mo) rats. Morphological observation by electron microscopy showed that the ovarian nerve contains mainly unmyelinated fibers with only a small percentage (less than 4%) of myelinated fibers in either age group. The number of unmyelinated fibers tended to decrease in aged rats (717 +/- 59) compared to adult rats (801 +/- 48), especially in fibers of smaller diameter, although this difference was not statistically significant. The maximum conduction velocity of unmyelinated fibers within the ovarian nerve was similar when compared between adult (1.05 +/- 0.04 m/s) and aged (1.02 +/- 0.05 m/s) rats. Under anesthesia, electrical stimulation of the distal portion of a severed ovarian nerve reduced ovarian blood flow, as measured by laser Doppler flowmetry, when the stimulus intensity was above the threshold for unmyelinated C fibers. Stimulation of the ovarian nerve with supra-maximum intensity (10 V) at 2-20 Hz frequencies produced frequency-dependent reductions in ovarian blood flow in both adult and aged rats. There were no significant differences in magnitude of the reduction in ovarian blood flow with comparable frequencies of electrical stimulation of the ovarian nerve between adult and aged rats. Collectively, these data indicate that unmyelinated C fibers in ovarian nerve are maintained in number, size, conduction ability, and vasoconstrictor function in aged rats. (C) 2011 Elsevier B.V. All rights reserved.