OBJECTIVETo observe regulation of nitric oxide on c-fos expression in osteoblastic cells in response to changes in wall-shear stress in vitro.

METHODSIsolated and purified osteoblastic cells from the calvaria of newborn SD rats were cultured and passaged. The third generation cells, pre-treated with 10% FBS DMEM, 0.3 mmol/L L-NMMA DMEM and 0.1 mmol/L SNP DMEM separately, were subjected to wall-shear stress of 1.2 Pa. Gene expression of the c-fos and NOS activity were studied before (0 min) and 10 min, 15 min, 30 min, 60 min after treated with wall-shear stress.

RESULTThe expression of c-fos mRNA was increased transiently after application of 1.2 Pa wall-shear stress in osteoblastic cells and peaked at 15 min. The expression of c-fos mRNA was decreased after pre-application with L-NMMA and increased after use of SNP.

CONCLUSIONChanges in the osteoblastic cells mechanical environment may cause a dramatic induction of NO and c-fos expression.