Paraphysectomy-induced stimulation of parathyroid glands in mature frogs (Rana catesbeiana): evidence for telencephalic regulation of parathyroid gland function.
The relationship of the paraphyseal-choroid plexus complex to parathyroid gland function was investigated in adult frogs. Light microscopy and morphometric analysis indicated that total parathyroid gland volume, cell volume and vascular volume doubled by 7-28 days after surgical removal of the paraphyseal-choroid plexus complex (paraphysectomy). This increase correlated with the appearance of large Golgi-associated vesicles, an increase in the apparent number of cytoplasmic dense-core granules, and PTH within the parenchymal cells as monitored by immunofluorescence. Twelve months after paraphysectomy, parathyroid glands became cystic with a central fluid-filled cavity surrounded by a stratified cuboidal cell layer. The parenchymal cells of cystic glands contained numerous cytoplasmic dense-core granules and were also positive for PTH. Radioimmunoassay of cystic parathyroid fluid indicated a PTH concentration of 2 micrograms/microliter; however, analysis by SDS-PAGE indicated a wide range of proteins in cystic fluid. The results of this study indicate that paraphysectomy induces stimulation of the parathyroid glands and suggest a role for the paraphyseal-choroid plexus complex in the regulation of amphibian parathyroid gland function.
D000818:Animals; D005260:Female; D005455:Fluorescent Antibody Technique; D008297:Male; D008854:Microscopy, Electron; D010280:Parathyroid Glands / Q000502:physiology*; D010281:Parathyroid Hormone / Q000032:analysis; D011863:Radioimmunoassay; D011892:Rana catesbeiana; D013687:Telencephalon / Q000502:physiology*
D010281:Parathyroid Hormone