Differential Androgen Modulation of Acid Phosphatase Isozymes in Primary Cultures of Rat Ventral Prostate Epithelial and Stromal Cells*

Abstract

The influence of androgen on prostate differentiated cell function was investigated using primary cultures of rat ventral prostate epithelial and stromal cells developed from sexually immature animals (21 days of age). As a biochemical marker of androgen action, total acid phosphatase activity, which comprises both the secretory and lysosomal isoforms, was measured. Testosterone increased total acid phosphatase activity approximately 2-fold in epithelial cell cultures. This increase occurred only after the cessation of cell proliferation (i.e. upon reaching a confluent monolayer). In contrast, stromal cells showed no significant change in total acid phosphatase activity in response to androgen. Polyacrylamide gel isoelectric focusing of total acid phosphatase activity from epithelial and stromal cell extracts revealed that secretory acid phosphatase activity was localized exclusively in the epithelial cells while lysosomal acid phosphatase activity was present in both cell types. Furthermore, the androgen-induced increases in epithelial total acid phosphatase activity were found to result from increases in the secretory isoform.