The effect of phenytoin on parathyroid hormone stimulated cAMP activity in cultured murine osteoblasts.
Cells were isolated by sequential collagenase digestion from the parietal segments of one day old mice (Swiss albino BNL strain) and characterized for osteoblast parameters by alkaline phosphatase histochemistry and bovine parathyroid hormone (bPTH-(1-34] induced cAMP activity (protein binding assay). Phenytoin (DPH) reduced PTH stimulated cAMP activity nearly 3-fold in the presence and nearly 1.5-fold in the absence of added calcium. In the absence of PTH, DPH exerted no significant effect. Bay-K-8644, a calcium channel activator, appeared to approximate the PTH stimulation of cAMP activity, even in the presence of DPH. This study demonstrates that DPH has a direct effect on PTH stimulated cAMP activity in cultured murine osteoblasts.
Auszmann
J M
JM
Department of Histology and Cell Biology, David B. Kriser Dental Center, New York University College of Dentistry, New York 10010.
Vernillo
A T
AT
Fine
A S
AS
Rifkin
B R
BR
D000469:Alkaline Phosphatase; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D006651:Histocytochemistry; D007124:Immunoenzyme Techniques; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010672:Phenytoin / Q000494:pharmacology*
D010281:Parathyroid Hormone; D010672:Phenytoin; D000242:Cyclic AMP; D000469:Alkaline Phosphatase; D002118:Calcium