title: Combined effect of calcitonin and glucocorticoid hormone on calcium content of cultured bone cells.
abstract: The combined effect of calcitonin and triamcinolone acetonide on Ca2+ content in cultured bone cells was studied. Cultures were first preincubated with 45Ca for 24 hrs thus achieving a steady state between the extracellular and intracellular 45Ca2+. Calcitonin was added for 24 hrs and subsequently, triamcinolone acetonide was added for time intervals ranging from 1 to 24 hrs. Calcitonin induced a significant increase in the content of cellular exchangeable Ca2+. When triamcinolone was added to cultures pretreated with calcitonin a marked efflux activity was noted. Concomitant ultrastructural histochemical examinations, using the K-pyroenthymonate fixation method, further substantiated the above finding: calcitonin treated cells revealed increased number of Ca-pyroenthymonate precipitates, whereas the combined treatment led to the disappearance of such Ca-aggregates.
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism*; D002116:Calcitonin / Q000494:pharmacology*; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D002462:Cell Membrane / Q000032:analysis; D002478:Cells, Cultured; D003593:Cytoplasm / Q000032:analysis; D051381:Rats; D014221:Triamcinolone / Q000494:pharmacology*
chemical_list: D014221:Triamcinolone; D002116:Calcitonin; D002118:Calcium