Osteoclasts from medullary bone of egg-laying Japanese quail do not express the putative calcium 'receptor'.
The present study reports the contrasting effects of extracellular calcium ([Ca2+]e) elevation on cytosolic free calcium levels ([Ca2+]i) of osteoclasts, freshly isolated either from medullary bone of the egg-laying Japanese quail or from rat cortical bone. [Ca2+]i was measured in single osteoclasts using the Ca(2+)-sensitive fluorochrome, Indo-1. We found that elevation of [Ca2+]e failed to induce a rise of [Ca2+]i in quail osteoclasts, whilst causing an elevation of [Ca2+]i in rat osteoclasts. The calcium ionophore, ionomycin, led to a sustained elevation of [Ca2+]i in both cell types. These findings suggest that osteoclasts isolated from egg-laying quail do not possess the calcium sensor or 'receptor' that appears to be vital for the survival and function of rat osteoclasts.
Bascal
Z A
ZA
Division of Pharmacology, School of Pharmacy and Biomedical Sciences, Portsmouth Polytechnic.
Moonga
B S
BS
Dacke
C G
CG
Zaidi
M
M
D000818:Animals; D001842:Bone and Bones / Q000166:cytology*; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D003370:Coturnix; D005109:Extracellular Matrix / Q000737:chemistry; D005260:Female; D015759:Ionomycin / Q000494:pharmacology; D008297:Male; D010010:Osteoclasts / Q000737:chemistry / Q000648:ultrastructure*; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000032:analysis* / Q000378:metabolism; D013050:Spectrometry, Fluorescence
D011956:Receptors, Cell Surface; D015759:Ionomycin; D002118:Calcium