Fine structural alterations of parathyroid glands in response to experimental and spontaneous changes of calcium in extracellular fluids

摘要: Abstract The parathyroid glands are composed of chief cells, in different stages secretory activity, arranged spherical groups joined by fine collagen fibers. Small, membrane-limited granules present the cytoplasm cells but fewer numbers than many other polypeptide-hormone-secreting cells. Fusion with plasma membrane and extrusion within cytoplasmic protuberances into perivascular space suggested a mechanism for secretion hormone After long-term hypercalcemia, were primarily inactive stage cycle atrophic cells; numerous accumulated some In response to hypocalcemia, actively secreting predominated glands; organelles concerned protein synthesis hormonal well developed depleted storage granules. Hyperactive vacuolated observed hypocalcemic stimulation, had large amounts glycogen.