The objectives of the proposed investigative effort are directed toward the achievement of a precise definition of the culture environment required for the successful, repetitive, in vitro growth of prostatic cells that resemble the cell in its specific tissue of origin - the human prostate. Routine growth of primary prostatic-like cells has been achieved during the first 18 months of this contract. Accordingly, this renewal request involves an expansion of our efforts to fully characterize the identity and function of these cells, as well as to develop a microcarrier suspension culture system suitable for production and distribution of such cells to other laboratories. To fully characterize and identify these cultured cells will, of course, involve direct culture of cells from various prostate segments. This will be done to further our understanding of not only the conditions required for culture - type of hormonal media supplement - but also of the prostate itself in health and disease. Studies of the "calcium mobilization factor" as demonstrated in such cultures will be continued, as well as the isoenzymes of acid phosphatase and the kinetics of citrate secretion. Ultrastructural analyses will be integrated with the above studies.