S. Ceccatelli et al., IMMUNOHISTOCHEMICAL DEMONSTRATION OF NITRIC-OXIDE SYNTHASE IN THE PERIPHERAL AUTONOMIC NERVOUS-SYSTEM, Brain research, 656(2), 1994, pp. 381-395
In the present immunohistochemical study the distribution of nitric ox
ide synthase (NOS) was studied in various autonomic ganglia and in rel
ated peripheral tissues of the rat. For comparison some other neuronal
markers including acetylcholinesterase and tyrosine hydroxylase as we
ll as several neuropeptides were analysed on adjacent or the same sect
ions. The distribution of NOS-like immunoreactivity (LI) and of these
other markers has been semiquantitatively summarized. In some parasymp
athetic ganglia such as the sphenopalatine and submandibular ganglia N
OS-LI was present in most ganglion cells, at least partly coexisting w
ith peptide histidine isoleucine (PHI), vasoactive intestinal polypept
ide (VIP) and neuropeptide tyrosine (NPY). In the pelvic ganglia a com
paratively smaller proportion of neurons was NOS-positive and they oft
en contained VIP-LI and less frequently NPY-LI. In the tissues innerva
ted by these ganglia, such as nasal mucosa and salivary glands, NOS-po
sitive fibers were observed around blood vessels and within the glandu
lar parenchyma, although generally less abundant than VIP/PHI nerves,
while in the uterus, vas deferens and penis a more close correlation w
as seen. NOS-positive fibers were also widely distributed in other tis
sues. In the sympathetic ganglia NOS-LI was mainly present in dense fi
ber networks, which disappeared after transection of the sympathetic t
runc central to the ganglion. Since many cell bodies in the sympatheti
c lateral column of the spinal cord also were NOS-positive, it is like
ly that the majority of preganglionic fibers innervating sympathetic g
anglia are NOS-positive. VIP-positive cells in stellate ganglia did no
t contain NOS-LI. The present results suggest that NO may be a messeng
er molecule both in parasympathetic postganglionic neurons and in preg
anglionic sympathetic neurons.