Localization of calcium regulatory hormones in fish.
Immunocytochemical localization of hypocalcin, a hypocalcemic factor in the corpuscles of Stannius (CS), in American eels was examined at the light (ABC method) and electron microscopic (protein A-gold technique) levels with the specific antiserum raised against purified rainbow trout hypocalcin. Only type 1 cells in the CS were immunoreactive in the light microscopic immunocytochemistry. At the electron microscopic level, however, hypocalcin immunoreactivity was observed in secretory granules of both type 1 and type 2 cells. Our findings may indicate that type 1 cells are the main source of hypocalcin, but that type 2 cells also produce it, suggesting that the presence of two cell types reflects different physiological conditions of a single cell type, rather than functionally different cell types.In addition, we summarize our recent data on the localization of other calcium regulatory, or putative calcium regulatory, hormones in fish: parathyroid hormone, calcitonin and calcitonin gene-related peptide.
Department of Physiology, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.
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Kaneko
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Harvey
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Kline
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Pang