Glucocorticoid and 1,25-Dihydroxyvitamin D Modulate the Degree of Adenosine 3′,5′-Monophosphate- Dependent Protein Kinase Isoenzyme I and II Activation by Parathyroid Hormone in Rat Osteosarcoma Cells*

摘要: Abstract Glucocorticoid increases and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] decreases PTH activation of adenylate cyclase cAMP-dependent protein kinase in rat osteosarcoma cells (ROS 17/2.8). Since selective isoenzyme may account for specific physiological hormonal responses, we investigated steroid effects on isoenzymes I II response to using a new ion exchange separation procedure. Pretreatment 2 days with the glucocorticoid triamcinolone acetonide (TRM) or 1,25-(OH)2D3 altered degree by accordance their modulation intracellular cAMP accumulation, but did not alter amount each present order which were activated. In all treatment groups was preferentially activated low doses PTH, while high concentrations both isoenzymes, as predicted relative affinities isoenz...