EFFECT OF SYMPATHECTOMY ON THE PHENOTYPE OF SMOOTH-MUSCLE CELLS OF MIDDLE CEREBRAL AND EAR ARTERIES OF HYPERLIPIDEMIC RABBITS

This study was carried out to determine whether sympathectomy influenc es the phenotypic modulation of smooth muscle cells in the peripheral and cerebral arteries of heritable hyperlipidaemic rabbits. Unilateral superior cervical ganglionectomy (common origin of innervation to the middle cerebral artery and the central ear artery) was performed on f our Watanabe heritable hyperlipidaemic rabbits. Cross-sections of the ipsi- (sympathectomized) and the contralateral (intact) cerebral and e ar arteries were prepared 2 months later and labelled with monoclonal antibodies against vimentin and desmin, two markers of the differentia tion of smooth muscle cells, and alpha-smooth muscle actin, a marker o f these cells. Sections from control and sympathectomized arteries wer e analysed with a confocal laser scanning microscope. Compared with co ntralateral intact ear arteries, the sympathectomized ear artery devel oped a thickened intima with dedifferentiated smooth muscle cells, exp ressing alpha-smooth muscle actin but no desmin, whereas the middle ce rebral artery remained unchanged. These results suggest that sympathec tomy may favour the progression of atherosclerosis in peripheral but n ot in cerebral arteries of Watanabe heritable hyperlipidaemic rabbits.