9511677 Mulroney Removal of one kidney (uninephrectomy) results in the rapid growth of the remaining kidney. Recent advances using whole animal, cellular, and molecular biologic techniques have shown that there are different mechanisms involved in this accelerated growth. Using this model of rapid renal growth, Dr. Mulroney has determined that different growth factors are stimulated in young and adult male animals, and they appear to govern the type of growth that occurs in the regenerating kidney, vis a vis hyperplasia (cell multiplication) and hypertrophy (enlargement of existing cells). Preliminary findings for the present proposal have found that there are also differences in the mechanism and renal growth response in adult female animals, compared with adult males. These age and sex differences have important implications regarding the cellular and molecular controls for cell growth in vivo and defining the mechanisms involved in these pathways could provide information on basic influencing the growth process. The broad objective of this proposal is to determine the effects of the gonadal (sex) steroids on the compensatory renal growth that occurs following uninephrectomy, and identify their importance in the final outcome of the type of growth that occurs. These studies should provide important basic information regarding the stimuli and mechanisms governing cell and organ growth. ***
