Showing papers on "Myofibroblast published in 1981"

Vascular smooth muscle cells differ from other smooth muscle cells: predominance of vimentin filaments and a specific alpha-type actin.

Abstract: Smooth muscle cells of the digestive, respiratory, and urogenital tracts contain desmin as their major, if not exclusive, intermediate-size filament constituent and also show a predominance of gamma-type smooth muscle actin. We have now examined smooth muscle tissue of different blood vessels (e.g., aorta, small arteries, arterioles, venules, and vena cava) from various mammals (man, cow, pig, rabbit, rat) by one- and two-dimensional gel electrophoresis of cell proteins and by immunofluorescence microscopy using antibodies to different intermediate-sized filament proteins. Intermediate-sized filaments of vascular smooth muscle cells contain abundant amounts of vimentin and little, if any, desmin. On gel electrophoresis, vascular smooth muscle vimentin appears as two isoelectric variants of apparent pI values of 5.30 and 5.29, shows the characteristic series of proteolytic fragments, and is one of the major cell proteins. Thus vimentin has been demonstrated in a smooth muscle cell present in the body. Vascular smooth muscle cells are also distinguished by the predominance of a smooth muscle-specific alpha-type actin, whereas gamma-type smooth muscle actin is present only as a minor component. It is proposed that the intermediate filament and actin composition of vascular smooth muscle cells reflects a differentiation pathway separate from that of other smooth muscle cells and may be related to special functions and pathological disorders of blood vessels.

The intermediate filament proteins of rabbit vascular smooth muscle: immunofluorescent studies of desmin and vimentin

Abstract: The localization of desmin and vimentin in rabbit vascular smooth muscle was studied using the fluorescent antibody technique. Desmin and vimentin were present in the smooth muscle cells of the portal anterior mesenteric vein, renal vein and renal artery. All endothelial cells and the smooth muscle cells of the abdominal aorta and main pulmonary artery contained only vimentin. The results suggest that desmin and vimentin are differentially distributed in rabbit vascular smooth muscle and that both may occur in a single blood vessel.

Use of colchicine to inhibit wound contraction.

Abstract: Rats and rabbits with full-thickness skin excisions were treated topically and systemically with colchicine. Wounds which had been covered by an occlusive plastic dressing and treated topically showed an inhibition of wound contraction, but only at the expense of local toxicity. Systemic colchicine had no significant effect on contraction in the doses tested. Electron microscopy of colchicine-treated wounds showed the presence of inflammatory cells and myofibroblasts containing microtubules. Colchicine inhibits wound contraction, probably by a local toxic effect rather than by any observable specific inhibition of myofibroblast structures.

Electron microscopic study of carcinoma of the colon.

Abstract: Summary During electron microscopic studies of 24 carcinomas of the colon the authors compared the ultrastructural characteristics of tumorous epithelial cells of various degrees of differentiation. Beside the epithelial elements, the myofibroblast reaction, considered to be a local immune reaction due to invasive tumour cells, observable in the stroma of tumours was also treated in detail. It was observed that myofibroblasts develop from the fibroblasts of the matrix of colonic mucosa.