Calcium signal induced by mechanical perturbation of osteoclasts.
Multinucleated osteoclasts from rabbit long bone, 1-6 days in culture, respond to mechanical perturbation with a transient increase of intracellular calcium concentration ([Ca2+]i), as measured with the fluorescent indicator fluo-3 on a confocal laser scanning microscope. In experiments with different extracellular calcium concentrations (from 11.8 mM to calcium-free), the incidence, the magnitude, and the duration of [Ca2+]i responses decreases with decreasing bathing [Ca2+]. Following mechanical perturbation, a thapsigargin-induced [Ca2+]i response has a lower magnitude than the thapsigargin-induced response without mechanical perturbation. In thapsigargin-pretreated osteoclasts the mechanical perturbation-induced rise in [Ca2+]i is larger and longer than in control cells. Ni2+ inhibits the incidence and decreases both the magnitude and the duration of the responses, while nifedipine, verapamil, and Gd3+ have no effect. These measurements show that rabbit osteoclasts transduce a mechanical perturbation of the cell membrane into a [Ca2+]i signal via both a calcium influx and an internal calcium release.
Xia
S L
SL
Medical Research Council Group in Periodontal Physiology, Faculty of Dentistry, University of Toronto, Ontario, Canada.
Ferrier
J
J
D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media; D007425:Intracellular Membranes / Q000378:metabolism; D007473:Ion Channels / Q000037:antagonists & inhibitors; D008846:Micromanipulation; D018613:Microscopy, Confocal; D009994:Osmolar Concentration; D010010:Osteoclasts / Q000502:physiology*; D010812:Physical Stimulation; D011817:Rabbits; D015398:Signal Transduction; D013314:Stress, Mechanical; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin
D003470:Culture Media; D007473:Ion Channels; D013729:Terpenes; D019284:Thapsigargin; D000252:Calcium-Transporting ATPases; D002118:Calcium