Grant: Research Tools and Instruments - Category 1 (<$150,000)

This application is for a multi-detector gamma counter for use in fish physiology research in the laboratories of J. Chang G. Goss and J. Stafford. Dr. Chang studies the control of growth hormone and gonadotropin release and synthesis in goldfish with emphasis on how intracellular signalling pathways integrate and mediate the differential effects of multiple neuroendocrine regulators on hormone synthesis and secretion in goldfish gonadotropes and somatotropes. The ability to accurately quantify hormone secretion and cellular hormone content by 125I-based radioimmunoassay is essential for this research program. Dr. Goss investigates how ionic, fluid and acid/base balance in freshwater and marine fish species are regulated. His research focuses include elucidating the identity and functional regulation of transporters involved, as well as how the differential localization of these transporters on different gill cell populations contribute to the maintenance of homeostasis under normal environmental challenges and when exposed to water-borne pharmaceuticals and nanoparticles. One key question is the regulation of Na+ flux and Na+ transporter systems. The ability to monitor 22Na flux is critical for such studies. Dr. Stafford studies the receptor-ligand systems regulating the innate immune response in fish and how these components regulate the ability of cytotoxic lymphocytes to eliminate infected cells. A 51Cr release assay is a standard technique to monitor cytotoxic lymphocyte responses required for his research. Our 18-yr old gamma counters are no longer functioning reliably. They also do not properly monitor Na and Cr isotopes. The Perkin Elmer Wizard 2470 applied for has the capacity to process the large number of hormone assays required for the Chang lab and is also designed to monitor 22Na and 51Cr. The replacement of the current counters with the one applied for is absolutely essential for the functioning and continual success of three highly productive research programs and is urgently needed.