Isolation of guinea pig gastric smooth muscle cells

A method of isolating guinea pig gastric smooth muscle cells was established in order to investigate gastric contractile mechanisms at the cellular level. Strips of gastric muscle were digested enzymatically with collagenase and dispase, and the smooth muscle cells isolated on a percoll density gradient, with a purity of 80-90%. The muscle cells were over 90% viable and demonstrated a remarkable contractile response to carbachol stimulation in a dose-dependent manner, from 10(-7) M to 10(-4) M. Intracellular Ca2+ concentration following carbachol stimulation was monitored, since Ca2+ is essential to the contractile process, and it was found to increase almost in parallel with contraction. These results suggest that the measurement of intracellular Ca2+ concentration is useful for analyzing the contractile mechanism of isolated smooth muscle cells.