Expression of cytoskeletal proteins and ATPase activity in bovine femoral artery and vein intima

Abstract

Intima1 cells play an important role in the biology of the vascular wall. Variability in the metabolic activity of intimal smooth muscle cells (SMC), as well as the differential expression of cellular cytoskeletal proteins depend on factors such as degree of differentiation, aging, atherosclerosis, etc. Myosin ATPase activity and cytoskeletal proteins were studied in the intima of bovine femoral arteries and veins of mature animals. In some arteries the intima was thickened and two distinct layers - inner elastic hyperplastic (EHL) and outer, musculo-elastic (MEL) were observed. ATPase activity was well defined in endothelial cells (EC) as well as in SMC. However, differential enzymatic expression was observed in thickened intimas. SMC in the EHL were ATPase negative, while in the MEL they were ATPase positive. Al1 EC and SMC in the «normal» intimas were vimentin positive, desmin and cytokeratin negative. In vessels with thickened intimas, the EHL showed intensive vimentin positivity; in the MEL desmin immunoreactive SMC were numerous as were as those in the media. Vimentin-positive SMC occupied their innermost part. Differences in the expression of ATPase activity and cytoskeletal proteins is discussed in terms of possible migration of media1 SMC andlor morphological modulation observed in vessels with altered vascular walls.