Activation and inactivation of the osteoclast Ca2+ receptor by the trivalent cation, La3+.
We report changes in the cytosolic Ca2+ concentration ([Ca2+]i) of single rat osteoclasts in response to Ca2+ receptor activation by micromolar concentrations of the lanthanide metal cation, La3+. The extracellular application of La3+ induced a concentration-dependent elevation of cytosolic [Ca2+]. Prior conditioning of osteoclasts with La3+ resulted in a concentration-dependent reduction of the response to a subsequent application of a maximally effective concentration of Ni2+, a known agonist of the osteoclast Ca2+ receptor. The results establish that the osteoclast Ca2+ receptor is highly sensitive to activation and inactivation by the trivalent cation, La3+.
Shankar
V S
VS
Bone and Mineral Metabolism Unit, St. George's Hospital Medical School, London.
Alam
A S
AS
Bax
C M
CM
Bax
B E
BE
Pazianas
M
M
Huang
C L
CL
Zaidi
M
M
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000187:drug effects / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D007811:Lanthanum / Q000494:pharmacology*; D009532:Nickel / Q000494:pharmacology; D010010:Osteoclasts / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013050:Spectrometry, Fluorescence
D002135:Calcium-Binding Proteins; D007811:Lanthanum; D009532:Nickel; D002118:Calcium