Inducible and endothelial nitric oxide synthase expression in human atherogenesis: an immunohistochemical and ultrastructural study.
BACKGROUND
Nitric oxide has been proven to play an important role in the maintenance of vascular tone and structure. Impairment of nitric oxide production is an early indicator of atherosclerosis, but not much is known about the real mechanisms underlying this phenomenon.


METHODS
In the present study, immunocytochemical methods have been used to analyze the patterns of expression of endothelial nitric oxide synthase and inducible nitric oxide synthase proteins in healthy and atherosclerotic human aortae using both confocal laser scanning microscopy and electron microscopy.


RESULTS
Induction of the expression of endothelial nitric oxide synthase and inducible nitric oxide synthase proteins was observed in smooth muscle cells of atherosclerotic human aortae. Altered nitric oxide synthase expression was reported in atheromatous plaques and in apparently normal vascular tissues adjacent to the lesions.


CONCLUSIONS
Our data confirm and extend previous findings of a direct relationship between dysregulation of nitric oxide pathway and atherosclerosis, suggesting another possible mechanism by which nitric oxide synthase system abnormalities may promote vascular dysfunction during human atherogenesis. Changes in nitric oxide production might be the primary step in the development of atheroma.
Perrotta
Ida
I
Department of Ecology, University of Calabria, Arcavacata di Rende, Cosenza, Italy. idaperrotta@yahoo.it
Brunelli
Elvira
E
Sciangula
Alfonso
A
Zuccalà
Valeria
V
Donato
Giuseppe
G
Tripepi
Sandro
S
Martinelli
Gian Luca
GL
Cassese
Mauro
M
D000368:Aged; D001011:Aorta / Q000378:metabolism* / Q000648:ultrastructure; D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000648:ultrastructure; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis*
C496319:NOS2 protein, human; C496314:NOS3 protein, human; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III