Iso ation and characterization of guinea-pig tracheal smooth muscle cells that retain differentiated function in long-te m

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 'a 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 inforabout the regulation of tracheal smooth muscle cell growth and differentiation .