Vanhatalo S, Parkkisenniemi U, Steinbusch H W, de Vente J, Klinge E
Department of Anatomy, Institute of Biomedicine, University of Helsinki, P.O. Box 9, 00014, Helsinki, Finland.
J Chem Neuroanat. 2000 Jun;19(2):81-91. doi: 10.1016/s0891-0618(00)00053-3.
The distribution of immunoreactivity (IR) for the neuropeptide vasoactive intestinal polypeptide (VIP) and neuronal nitric oxide synthase (nNOS) in the bovine retractor penis muscle (RP) and penile artery (PA) was studied by using two different methods. The distribution of these immunoreactivities was also compared with that of the immunoreactivity for cyclic guanosine monophosphate (cGMP). In both tissues the nerve fibers and terminals immunoreactive for VIP had a distribution that was completely different from that of the nerve fibers and terminals immunoreactive for nNOS. This contrasts with the previous observations in penile smooth muscle of other species. In the RP, as well as in the PA, many of the VIP-IR fibers were also immunoreactive for neurofilaments (NF), whereas the nNOS-IR fibers were consistently devoid of NF-IR. Stimulation with sodium nitroprusside, a nitric oxide donor, considerably increased cGMP-IR in the smooth muscle cells in both RP and PA, and in several nerve fibers in PA. Many of these cGMP-IR nerve fibers exhibited nNOS-IR, whereas none of them was immunoreactive for VIP. Our results suggest that the degree of coexistence of VIP-IR and nNOS-IR in the nerve fibers and terminals innervating penile smooth muscle show wide species differences. They also suggest that the mechanisms by which VIP could be involved in neurogenic penile erection may vary between species.
采用两种不同方法研究了神经肽血管活性肠肽（VIP）和神经元型一氧化氮合酶（nNOS）在牛阴茎退缩肌（RP）和阴茎动脉（PA）中的免疫反应性（IR）分布。还将这些免疫反应性的分布与环磷酸鸟苷（cGMP）的免疫反应性分布进行了比较。在这两种组织中，对VIP免疫反应的神经纤维和终末的分布与对nNOS免疫反应的神经纤维和终末的分布完全不同。这与之前在其他物种阴茎平滑肌中的观察结果形成对比。在RP以及PA中，许多VIP免疫反应纤维也对神经丝（NF）呈免疫反应，而nNOS免疫反应纤维始终缺乏NF免疫反应。用一氧化氮供体硝普钠刺激后，RP和PA的平滑肌细胞以及PA的一些神经纤维中的cGMP免疫反应性显著增加。许多这些cGMP免疫反应神经纤维表现出nNOS免疫反应，而它们中没有一个对VIP呈免疫反应。我们的结果表明，支配阴茎平滑肌的神经纤维和终末中VIP免疫反应和nNOS免疫反应的共存程度存在广泛的物种差异。它们还表明，VIP参与神经源性阴茎勃起的机制可能因物种而异。
