Multiple isozymes of Ca2+/phospholipid-dependent protein kinase (PKC) were isolated from the rat ventral prostate. The enzyme exists mainly as type II (β), and type III (α) forms, and it is possible that type II isozyme may comprise the subspecies β1 and β2. The total and specific activities of prostatic PKC isoforms were reduced in castrated animals; this decrease was specific since administration of androgens to castrated animals reversed such a decline. Also, there was a differential response to androgen deprivation so that type III isozyme declined at a faster rate than that of type II. Thus, our studies show for the first time that PKC of the rat ventral prostate comprises multiple isozymes, and that the activity of these various forms are differentially regulated by androgens.
