Creatine phosphokinase in prostatic tissue.

A histochemical study of creatine phosphokinase (CPK) in the rat ventral prostate revealed that the epithelial cells had a high cytoplasmic activity which was retained or even increased when the cells were atrophic as a consequence of castration. Both the fibromuscular stroma, which is prominent in the ventral prostate of castrated rats, and the secretion had a high level of activity. In human benign prostatic tissue where CPK was present in the epithelium, secretion and stroma, pronounced differences in activity could sometimes be observed between the epithelium of adjacent acini and also between cells in the same acinus. There was no obvious correlation between CPK activity and degree of epithelial hyperplasia. The activity in carcinomatous prostatic epithelial cells varied considerably between specimen from different patients but was uniform within a given specimen in contrast to the variation of epithelial CPK activity within non-carcinomatous tissue. Thus, a difference in the pattern of CPK activity was observed between malignant and non-malignant epithelial cells.