THE SMOOTH MUSCLE CELL

TLDR

Smooth muscle cells isolated from the inner media and intima of immature guinea pig aorta were cultured for up to eight weeks. The cultured cells retained smooth‑muscle morphology, formed multilayered sheets, produced microfibrils and basement‑membrane–like material resembling elastic fiber components, demonstrating that aortic smooth muscle functions as a connective‑tissue synthetic cell.

Abstract

Smooth muscle derived from the inner media and intima of immature guinea pig aorta were grown for up to 8 wk in cell culture. The cells maintained the morphology of smooth muscle at all phases of their growth in culture. After growing to confluency, they grew in multiple overlapping layers. By 4 wk in culture, microfibrils (110 A) appeared within the spaces between the layers of cells. Basement membrane-like material also appeared adjacent to the cells. Analysis of the microfibrils showed that they have an amino acid composition similar to that of the microfibrillar protein of the intact elastic fiber. These investigations coupled with the radioautographic observations of the ability of aortic smooth muscle to synthesize and secrete extracellular proteins demonstrate that this cell is a connective tissue synthetic cell.