Maintenance of contractility in dissociated smooth muscle: low-density cultures in a defined medium.

The loss of contractility in long-term cultures of dissociated smooth muscle is such an established observation that the lack of contractility of cultured smooth muscle cells is often not even noted. This report describes methods of dissociating and culturing smooth muscle cells from the avian amnion that maintain contractility for > 1 mo in a defined medium. Because contractility was assessed by monitoring the contractions of individual cells to neurotransmitter-related substances, it is clear that these cells maintained both contractility and pharmacological responsiveness. However, when amniotic smooth muscle cells were dissociated with enzymes containing impurities or cultured in the presence of serum, they flattened and lost contractility, as reported for many other types of smooth muscle.