Changes in the distribution of nitric oxide synthase immunoreactive nerve fibers in the chronically hypoxic rat carotid body.
The distribution of nitric oxide synthase (NOS) immunoreactive nerve fibers in the carotid body was compared between normoxic and chronically hypoxic rats (10% O2 and 3.0-4.0% CO2 for 3 months). NOS immunoreactive fibers appeared as thin processes with many varicosities. They were distributed predominantly around small arteries and arterioles, and around clusters of glomus cells. When expressed by the density of varicosities per unit area in the parenchyma, the density of NOS fibers associated with the vasculature and with the glomus cells in the chronically hypoxic carotid bodies was significantly decreased. Because nitric oxide (NO) is an inhibitory neuronal messenger in the normoxic carotid body, the present findings suggest that the sensory mechanisms in the hypoxic carotid body may be involved in 'disinhibition' resulting from reduced NO synthesis.
Kusakabe
T
T
Department of Anatomy, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
Matsuda
H
H
Harada
Y
Y
Hayashida
Y
Y
Gono
Y
Y
Kawakami
T
T
Takenaka
T
T
D000818:Animals; D000906:Antibodies; D001808:Blood Vessels / Q000201:enzymology; D002344:Carotid Body / Q000098:blood supply / Q000201:enzymology*; D002628:Chemoreceptor Cells / Q000201:enzymology; D000860:Hypoxia / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D009252:NADPH Dehydrogenase / Q000032:analysis / Q000276:immunology; D009412:Nerve Fibers / Q000201:enzymology*; D019001:Nitric Oxide Synthase / Q000032:analysis* / Q000276:immunology; D051381:Rats
D000906:Antibodies; D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase