Isolation and characterization of guinea-pig tracheal smooth muscle cells that retain differentiated function in long-term subculture.

A simple 30-min enzyme digestion procedure has been used to release guinea-pig tracheal smooth muscle cells that retain differentiated function in long-term subculture. Primary cell cultures initially consist of numerous epithelial colonies and 70-1000 morphologically differentiated smooth muscle cells per 600 mg (wet weight) tracheal tissue depending on the age of the animal. Both cell types proliferate to form a confluent monolayer within 5-17 days. Pure subcultures of tracheal smooth muscle cells are obtained by limited trypsin digestion of the primary culture. Eighty percent of these subcultured smooth muscle cells retain the ability to contract in response to histamine (10(-6) M) and to form reaggregates even after 20 or more passages. Examination of these cells by electron microscopy reveals both biosynthetic and contractile components of smooth muscle. Analysis of this dual phenotype may provide valuable information about the regulation of tracheal smooth muscle cell growth and differentiation.