title: Ca(2+)-induced Ca2+ oscillations in parathyroid cells.
abstract: Parathyroid cells from patients with hyperparathyroidism were first cultured in a growth cocktail supplemented version of Dulbecco's MEM/F12 medium and then used for measurements of the cytoplasmic Ca2+ concentration ([Ca2+]i). Elevation of extracellular Ca2+ from 0.5 to 1.5-3 mM often triggered rhythmic oscillations of [Ca2+]i. Whereas the amplitude of the oscillations remained constant their frequency (0.4-2.6 /min) increased with the Ca2+ concentration and there was sometimes transformation into sustained increase of [Ca2+]i at the highest extracellular Ca2+ concentration. The oscillations were abolished by the inorganic Ca2+ channel blocker Ce3+ and by K+ depolarisation, which lowered [Ca2+]i, as well as by thapsigargin, an inhibitor of the intracellular Ca(2+)-pumping ATPase. The data indicate that extracellular Ca2+ can trigger [Ca2+]i oscillations in parathyroid cells, dependent on mobilisation of the ion from intracellular Ca2+ stores and on influx through non-voltage dependent channels.
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology*; D002478:Cells, Cultured; D003470:Culture Media; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives; D006801:Humans; D006961:Hyperparathyroidism / Q000378:metabolism* / Q000473:pathology; D006965:Hyperplasia; D007700:Kinetics; D008856:Microscopy, Fluorescence; D009991:Oscillometry; D010280:Parathyroid Glands / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D010282:Parathyroid Neoplasms / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
chemical_list: D003470:Culture Media; D005456:Fluorescent Dyes; C049925:fura-2-am; D002118:Calcium; D016257:Fura-2