Effect of beta-alanyl-L-histidinato zinc on osteoblastic MC3T3-E1 cells: increases in alkaline phosphatase and...

The effect of beta-alanyl-L-histidinato zinc (AHZ) on bone metabolism was investigated in osteoblastic MC3T3-E1 cells. Cells were cultured for 3 days at 37 degrees C in a CO2 incubator in plastic dishes containing alpha-modified minimum essential medium supplemented with 10% fetal bovine serum. After the cultures, the medium was exchanged for that containing 0.1% bovine serum albumin plus various concentrations of AHZ or zinc sulfate, and the cells were cultured further for appropriate periods of time. The presence of AHZ (10(-6)-10(-4) mol/l) stimulated proliferation of cells. AHZ increased alkaline phosphatase activity in a dose-related manner up to 10(-5) mol/l; the increase was about 2-fold over the control value. Studies on the effect of actinomycin D or cycloheximide treatment indicated that AHZ may enhance de novo synthesis of the enzyme. AHZ also increased deoxyribonucleic acid (DNA) content dose dependently (10(-6)-10(-4) mol/l). This increase was completely blocked by treatment with cycloheximide. The AHZ (10(-5) mol/l)-induced increases in alkaline phosphatase activity and DNA content were entirely abolished by the presence of dipicolinate (10(-4) mol/l), a chelator of zinc, indicating that the effect of AHZ needs zinc. However, AHZ had a potent effect, more than that of zinc sulfate, on alkaline phosphatase activity and DNA content. The present results indicate that AHZ has a direct specific anabolic effect on osteoblastic cells in vitro and that this effect is related to protein synthesis.