Our broad objectives are to elucidate and to understand the mechanism by which the prostate gland performs the unique function of accumulating and secreting extraordinarily high levels of citric acid. Of particular importance is elucidation of the role of hormones in the regulation of prostate citrate production. In humans, prostatic neoplasms constitute the most prevalent neoplastic disease in man. Benign prostatic hypertrophy and prostatic carcinoma are characterized by major alterations in the ability to produce citrate. These studies will lead to the eventual understanding of the transformation of normal prostate cells to neoplastic cells and might provide a rational approach to the use of hormonal-related agents in the management of these neoplasms. This project focuses on the role of prolactin in the regulation of citrate production by lateral prostate of the rat. The lateral prostate is homologous to the lateral lobe of the human prostate. The studies will elucidate the effect of prolactin on citrate synthesis and citrate oxidation, and the mechanisms by which prolactin regulates citrate production. The program will elucidate the interaction among prolactin-zinc-citrate oxidation in prostate. Studies will also determine the mechanism by which prolactin regulates gene action associated with citrate synthesis. A comparative study with pig prostate will be conducted which will provide corroborating evidence that these relationships are likely applicable to human prostate.