Isolation of epithelial cells from toad bladder.

The epithelial cells of the toad bladder have been isolated by brief exposure to ethylenediaminetetraacetic acid followed by treatment with collagenase, DNAse, and the application of shearing forces. This approach eliminates the need for scraping of the mucosal surface and reduces mechanical damage during harvesting of the epithelium. The method yields intact, isolated epithelial cells and few clumps. The three major types of epithelial cells described in the intact toad bladder were present in the final preparation. The cellular contents of nucleic acids and proteins (in pg/cell) were: DNA 22.5 +/- 1.1; RNA, 12.9 +/- 0.6; and protein, 192 +/- 9. The isolated cells possess rates of oxygen consumption and amino acid incorporation higher than those of epithelial sheets obtained by collagenase treatment and scraping of the intact bladder. However, the production of cyclic nucleotides in response to stimulation by vasopressin and carbachol is comparable in both preparations.