Primary culture of normal rat adrenocortical cells. II. Quantitation of steroid dehydrogenase stain

A simple, rapid procedure for the quantitation of the histochemical stain for Δ<SUP>5</SUP>-3β-dehydrogenase (3β-HSD) in cultured cells is described. Adrenocortical cells were stained for 3β-HSD and then solubilized with 0.5N NaOH. The absorbance of the solubilized cell solution was measured at 570 nm and a linear relationship was obtained between the number of cells and the intensity of the absorption. It is shown that the regulation of 3β-HSD activity in primary cultures of normal rat adrenocortical cells can be monitored by the quantitative histochemical assay. The results show a good correlation with the data obtained by a biochemical assay for the enzyme