9310866 Holzwarth The mechanisms by which the central nervous system controls growth and development of cells in endocrine organs is not well understood. Since there is an extensive growth in the number of cells in the remaining adrenal gland following unilateral adrenalectomy, this physiological system may provide an excellent model to examine these underlying mechanisms. While it is known that the compensatory growth of the remaining adrenal is mediated by afferent and efferent autonomic adrenocortical nerves, the cellular mechanisms by which these autonomic nerves initiate and regulate cell proliferation have not been elucidated. During previous NSF support, Dr. Holzwarth identified a potent growth factor in adrenal glands, basic fibroblast growth factor (bFGF). She will now determine whether the adrenocortical nerves activate this local factor which then initiates the cell growth. Using state-of-the-art anatomical and molecular techniques, she will assess the mechanisms responsible for the proliferation of adrenocortical cells in vivo. Dr. Holzwarth will determine whether the cell proliferation is inhibited by immunological blockage of the growth factor. She will also measure how much bFGF is formed and where it is localized during the initial stages of compensatory growth. Finally, Dr. Holzwarth will determine whether cellular receptors present are altered during this proliferation. These experiments will provide new insights into how the nervous system controls cellular processes of non-neuronal cells as well as the mechanisms by which cells process and utilized their endogenous growth-promoting factors. Information gained from this work may eventually prove important in developing methods to prevent abnormal cell proliferation. ***
