Existence of parathyroid hormone binding sites on murine hemopoietic blast cells.
We demonstrated that 125I-labeled human parathyroid hormone (1-34;8,18-Nle,34-Tyr)[[125I]hPTH(1-34)] bound specifically to hemopoietic blast cells supported by granulocyte-macrophage colony-stimulating factor. Half-maximal inhibition of binding was achieved at concentrations of unlabeled hPTH(1-34) of about 5 x 10(-9)M. Insulin and hPTH(39-68) did not compete for PTH binding sites. Specific binding of hPTH(1-34) was detected in neither macrophages nor multinucleated cells (MNC's). Furthermore, treatment of hemopoietic blast cells with hPTH(1-34) stimulated MNC formation, and the range of concentrations (10(-10)-10(-8)M) over which hPTH(1-34) caused these effects was similar to that which inhibited the binding of [125I]hPTH(1-34). These findings suggest the presence of a PTH receptor on osteoclast precursors and the direct effect of PTH on them, resulting in osteoclast-mediated bone resorption.
Hakeda
Y
Y
Department of Oral Anatomy, Meikai University School of Dentistry, Saitama, Japan.
Hiura
K
K
Sato
T
T
Okazaki
R
R
Matsumoto
T
T
Ogata
E
E
Ishitani
R
R
Kumegawa
M
M
D000818:Animals; D001667:Binding, Competitive; D002116:Calcitonin / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000378:metabolism*; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D018016:Receptors, Parathyroid Hormone; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D007328:Insulin; D010281:Parathyroid Hormone; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; D018016:Receptors, Parathyroid Hormone; D002116:Calcitonin