[Studies on isolated smooth muscle cells. VI. Dispersion procedures for acetylcholine-sensitive smooth muscle cells of guinea pig (author's transl)].

Dispersion procedure of smooth muscle cells from collagenase-treated minces of guinea pig taenia coli and their response to acetylcholine were examined in order to apply the single smooth muscle cells to investigation of contraction mechanisms of smooth muscle. Pipetting the mince suspension was convenient procedure for the dispersion of single cells. For good yield of acetylcholine-sensitive cells, very mild pipetting was required although yield of single cells was lower. Under the condition, 10(3)-10(4) cells were obtained from 3-4 cm of taenia coli strip and about a half of the cells were responsive to acetylcholine. The cells became 40% of the original length by administration of 10 mM acetylcholine. Once the cells were dispersed and suspended in the physiological salt solution the cells lost the sensitivity to acetylcholine within 90 minutes while very mild pipetting of the mince suspension provided acetylcholine-sensitive cells over 3 hours. These single cells were applicable to investigation of contraction mechanisms of smooth muscle in addition to whole tissue as used so far. It was also suggested in the experiment that acetylcholine-sensitive site of cells might be damaged by exposure to physiological salt solution while it was well preserved in the tissue even though the tissue was digested by collagenase.