Isolation and contractile properties of single smooth muscle cells from guinea pig taenia caeci.

Abstract

A method for the isolation of single smooth muscle cells from guinea pig tenia ceci is described. The single cells were prepared by digestion with 0.3% collagenase and 0.6% trypsin inhibitor in Ca2+-free solution. This procedure produced a high yield of intact cells. Most cells obtained by this procedure were relaxed and showed large contractile responses to excitatory stimulus. Maximal responses of the single cells to acetylcholine (ACh), histamine and high K+ were attained within 20 s, and the percent decrease in cell length was 30-40%. Times for maximal responses of the single cells were shorter than those of the muscle strips. Single cells exhibited a dose-dependent graded response to Ca under depolarized conditions, ACh, histamine and high K+ and a voltage- and duration-dependent response to electrical stimulation. The ED50 of ACh in the single cells and in the muscle strips were about 2 .times. 10-8 and 1.5 .times. 10-7 M, respectively. The muscle strips had a lower sensitivity than the single cells to ACh. The generally smooth surface of the relaxed cell contrasted with the numerous evaginations present on the fully contracted cell. Evidently, single smooth muscle cells isolated from guinea pig using this techinque are, at present, better for physiological and pharmacological studies than are cells isolated using other techniques.