The neurons synthesizing nitric oxide (NO) that are part of the renal sympa
thetic pathways were located by double-staining for the neuronal isoform of
nitric oxide synthase (nNOS) using immunocytochemistry to identify NO-synt
hesizing neurons and transneuronal tracing following infection of the left
kidney with pseudorabies virus (PRV). Following kidney injection with PRV,
the animals survived 4-day post-inoculation prior to sacrifice and tissue p
rocessing. PRV-infected neurons that double-stained for nNOS were found in
the paraventricular hypothalamic nucleus (PVN), the raphe obscurus nucleus
(ROb), the ventromedial medulla (VMM), the rostral ventrolateral medulla (r
VLM) and the A5 cell group. In the thoracolumbar spinal cord, nNOS neurons
co-localized with PRV-infected cells in the dorsal horn in laminae I, III-V
ipsilateral to the injected kidney and in lamina X, the intermediolateral
cell column, the lateral funiculus, the intercalated nucleus and the centra
l autonomic area. We conclude that NO synthesizing cells may significantly
affect renal autonomic pathways in the rat by interacting with the renal se
nsory and sympathomotor circuitry at multiple sites. (C) 2001 Elsevier Scie
nce B.V. All rights reserved.