This is an International Scientific Meeting grant proposal to obtain support to cover part of the travel expenses for young scientists to attend the XIth meeting of the International Conferences on Calcium Regulating Hormones (ICCRH). The meeting will take place at the Palazzo dei Congressi and Centro Affari in Florence, Italy on April 24-29, l992. The ICCRH held its first meeting as the "Parathyroid Hormone Conference" in 1960 and has met regularly every 3 or 4 years since that time. The ICCRH is dedicated to international communication of new scientific findings and technologies related to the understanding of mineral ion and skeletal homeostasis and their clinical disorders. During its last three meetings (1983 Nice, France; 1986 Kobe, Japan; 1989 Montreal, Canada), the ICCRH has worked especially to foster active scientific interchange between younger scientists and trainees from several disciplines (biochemistry, molecular genetics, cell biology, and medicine) and their more senior colleagues in bone biology from around the world. The timing of the XIth ICCRH meeting is scientifically particularly propitious because major advances are occurring in the understanding of parathyroid hormone and calcitonin receptors; the roles of multiple cytokines in communication between osteoblasts and osteoclasts, in intracellular messenger systems in bone cells, in genetic factors in parathyroid tumors and the MEN I and II syndromes, in vitamin D receptors and actions, and in the pathogenesis and treatment of osteoporosis, to mention a few examples. Attendance at this meeting will enable an international group Of participants, who are engaged in developing the explosion of new knowledge in this area of basic biology and clinical medicine, to gain new insights and broad perspective on current research findings and directions. Funds are requested especially to enable the Organizing Committee to help support travel expenses for young investigator's who could not attend the meeting without assistance. Funding of this application will provide partial travel support and accommodation expenses in Florence for US and some foreign attendees. Preference will be given to those submitting abstracts for presentation who do not have sufficient resources to attend. The maximum travel grant made to an individual would be $1,000; other awards of $500 or $750 will be made on the basis of travel distance. Sponsorship by NIH will be acknowledged in the Program and Proceedings.