Defective regulation of the cytosolic Ca2+ activity in parathyroid cells from patients with hyperparathyroidism.
The parathyroid hormone (PTH) release and cytosolic Ca2+ activity were determined in normal bovine parathyroid cells and parathyroid cells obtained from patients with hyperparathyroidism (HPT). There was a sigmoid relation between the cytosolic Ca2+ activity and the extracellular calcium concentration between 0.5 and 6.0 mmol/l. The PTH release was inhibited in parallel with the rise in the cytosolic Ca2+ activity. Both the hormone release and the cytosolic Ca2+ activity were lower in cells from human adenomas and hyperplastic glands, and in comparison with the bovine preparations these cells had higher set points for the cytosolic Ca2+ activity and PTH release. There was a close correlation between the individual set points for the cytosolic Ca2+ activity and PTH release in a material containing both normal and pathological cells. The results indicate that the abnormal PTH release characteristic of HPT is due to a defective regulation of the cytosolic Ca2+ activity.
D000236:Adenoma / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002417:Cattle; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D006961:Hyperparathyroidism / Q000378:metabolism*; D007700:Kinetics; D010280:Parathyroid Glands / Q000187:drug effects / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000378:metabolism; D010282:Parathyroid Neoplasms / Q000378:metabolism
D010281:Parathyroid Hormone; D002118:Calcium