Effect of parathyroid hormone on proliferation and apoptosis of rat glomerular mesangial cells cultured in vitro

Objective To investigate the effect of PTH on proliferation and apoptosis of rat mesangial cells glomerular(GMC)cultured in vitro and explore its possible mechanism.Methods Rat GMCs were incubated with different concentrations of PTH and different times.Cell proliferation was assessed by MTT colorimetric assay.Cell cycle and apoptosis was analyzed by flow cytometry. Form of apoptosis was examined by vital staining of alcidine orange.The expression of c jun and c fos was determined by immunocytochemistry and computed video text analysis system.Results Incubation with 10-11～10-9mol/L PTH for 6 h and 12 h promoted the proliferation of GMC(P 0 05)and the most remarkable proliferation effect was observed by 10-9mol/L for 12 h.It also decreased the cell in G0～G1 phase and increased the cell in S+G2M phase ,and markedly promoted expression of c Jun and c fos(P 0 01). No obvious effects were found in 10-8mol/L for 6～12 h and in each concentration at 24 h,while GMC proliferation was significantly inhibited at 48 h(P 0 01),and cells were blocked at G0～G1 stage.In addition,PTH could markedly inhibit the expression of c jun and c fos(P 0 01),and could not induce apoptosis of GMC. Conclusions PTH possesses an effect on proliferation of rat GMC cultured in vitro,which was associated with time and dose. It can stimulate the proliferation in lower concentration and shorter time, and inhibit the proliferation in longer time. These effects,which can affect cell cycle,may be related to the expression of c Jun and c fos. PTH dose not induce apoptosis of rat GMCs cultured in vitro. Hyperparathyroidism may take part in the pathologic progress in remnant renal function of the chronic kidney disease.