Studies on isolated smooth muscle cells. IV. Isolation and acetylcholine-contraction of single smooth muscle cells from taenia coli of guinea-pig.

Abstract

In order to investigate the mode of contraction of smooth muscle cells in taenia coli of guinea-pig, single cells were isolated and contraction of the cells by acetylcholine and carbachol was examined. To isolate the single cells, enzymatic digestion of the tissue with collagenase and elastase was useful to preserve responsiveness to the cholinergic agents. When the single cells were exposed to acetylcholine, phasic contraction followed by tonic contraction occurred and the phasic contraction completed within 1 sec at 35°. Degree of contraction of the single cells was dependent on concentration of acetylcholine. The results suggested that contraction of individual cells in the tissue might reflect the contraction of the whole tissue directly. However, not all of the single cells is responsive to acetylcholine. Examination with a piece of enzymically digested mince resulted occasionally that contraction by acetylcholine did not occur in all the cells of the mince synchronously but contraction propagated gradually to the other cells. This result suggested that some cells in the tissue were originally not responsive to the cholinergic agents but there were contracted by stimuli propagated from the other cells.