Nitroxidergic innervation of guinea pig cerebral arteries.
The presence and distribution of nitric oxide synthase (NOS)-immunoreactive nerve fibers associated with the guinea pig major cerebral arteries was studied by means of immunohistochemical, histochemical and ultrastructural techniques. Anterior arteries of the circle of Willis received a rich supply of perivascular nerve fibers containing NOS immunoreactivity while posteriorly localized arteries presented a moderate to sparse innervation. A double immunofluorescence staining technique revealed that NOS was localized in nerve fibers distinct from those displaying substance P or tyrosine hydroxylase. Combined immunofluorescence and histochemical staining of the same preparation indicated that NOS immunoreactivity was localized in putative cholinergic nerve fibers (identified by their acetylcholinesterase content) and that NADPH-diaphorase activity (a marker for NOS-containing neurons) was found in nerves which also possessed VIP immunoreactivity. The ultrastructural study revealed that NOS immunoreactivity was present in numerous nerve varicosities at the adventitial-medial border. These results suggest that NO and VIP co-exist in putative parasympathetic nerve fibers supplying the guinea pig cerebral arteries and may be release together in response to nervous stimulation.
Barroso
C P
CP
Department of Cell Biology, Gulbenkian Institute of Science, Oeiras, Portugal.
Edvinsson
L
L
Zhang
W
W
Cunha e Sá
M
M
Springall
D R
DR
Polak
J M
JM
Gulbenkian
S
S
D000110:Acetylcholinesterase / Q000032:analysis; D000818:Animals; D002536:Cerebral Arteries / Q000294:innervation*; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D009252:NADPH Dehydrogenase / Q000032:analysis / Q000502:physiology*; D009412:Nerve Fibers / Q000737:chemistry* / Q000201:enzymology / Q000648:ultrastructure; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D009569:Nitric Oxide; D014660:Vasoactive Intestinal Peptide; D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase; D000110:Acetylcholinesterase