Edvinsson L, Mulder H, Goadsby P J, Uddman R
Department of Internal Medicine, Lund University Hospital, Sweden.
J Auton Nerv Syst. 1998 May 28;70(1-2):15-22. doi: 10.1016/s0165-1838(98)00033-2.
Nitric oxide (NO) is a novel neurotransmitter candidate to which a large number of physiological roles has been ascribed. In the present study, immunocytochemistry was used to demonstrate NO synthase (NOS) and to investigate possible co-localization with other neurotransmitters. In the trigeminal ganglion of the cat, a moderate number of NOS immunoreactive nerve cell bodies was seen, of which the major part also expressed calcitonin gene-related peptide (CGRP). The nerve cell bodies expressing NOS in the trigeminal ganglion were predominantly of small to medium size; while numerous cell bodies of varying size contained CGRP. With in situ hybridization using oligonucleotide probes, CGRP mRNA was demonstrated in almost all trigeminal neurons of the cat. Stimulation of the nasociliary nerve resulted in a frequency-dependent increase in ipsilateral local cortical blood flow by 30 +/- 6%. Administration of the NOS inhibitor NG-nitro-L-arginine-methylester (L-NAME) did not significantly alter this response when applied intravenously or on the cortical surface. Local cortical administration of the CGRP blocker h-CGRP (8-37) did not alter the cerebral vasodilator response to hypercapnia or resting flow. However, the nasociliary nerve response was reduced by 50% after h-CGRP (8-37), with a general shift to the right of the frequency-response curve. These data suggest that although NOS is seen in several trigeminal ganglion cells and coexists with CGRP in a subpopulation of the sensory neurons, its role in trigeminally mediated vasodilatation was not significant.
一氧化氮（NO）是一种新型神经递质候选物，人们已赋予其大量生理功能。在本研究中，采用免疫细胞化学方法来证明一氧化氮合酶（NOS）并研究其与其他神经递质的可能共定位情况。在猫的三叉神经节中，可见数量适中的NOS免疫反应性神经细胞体，其中大部分还表达降钙素基因相关肽（CGRP）。三叉神经节中表达NOS的神经细胞体主要为中小尺寸；而许多大小各异的细胞体含有CGRP。使用寡核苷酸探针进行原位杂交，在猫的几乎所有三叉神经元中都证明了CGRP mRNA的存在。刺激鼻睫神经导致同侧局部皮质血流量以频率依赖性方式增加30±6%。静脉内或在皮质表面应用NOS抑制剂NG-硝基-L-精氨酸甲酯（L-NAME）时，并未显著改变这种反应。在皮质局部应用CGRP阻断剂h-CGRP（8-37）并未改变对高碳酸血症或静息血流的脑血管舒张反应。然而，h-CGRP（8-37）处理后，鼻睫神经反应降低了50%，频率-反应曲线总体右移。这些数据表明，尽管在几个三叉神经节细胞中可见NOS，且在感觉神经元的一个亚群中与CGRP共存，但其在三叉神经介导的血管舒张中的作用并不显著。
