Beta-alanyl-L-histidinato zinc enhances various bone-regulating factors' effects on bone alkaline phosphatase...

The present investigation was undertaken to clarify the interaction of beta-alanyl-L-histidinato zinc (AHZ) and other bone-regulating factors on bone alkaline phosphatase in tissue culture. Calvariae were removed from weanling rats (3-week-old males) and cultured for periods up to 48 h in Dulbecco's modified Eagle medium. The experimental cultures contained 10(-5) mol/l AHZ which reveals in maximum effect on bone formation. Bone alkaline phosphatase activity was significantly increased by the presence of AHZ (10(-5) mol/l), insulin (10(-8) mol/l), sodium fluoride (10(-2) mol/l), aluminium sulfate (2 x 10(-3) mol/l), while the enzyme activity was not altered by estradiol (10(-9) mol/l), calcitonin (3 x 10(-8) mol/l), hydrocortisone (10(-8) mol/l), indomethacin (10(-6) mol/l) and imidazole (10(-3) mol/l). The presence of AHZ (10(-5) mol/l) clearly enhanced the calcitonin-, sodium fluoride- or diltiazem-increased bone alkaline phosphatase activity. Meanwhile, AHZ did not interact for the effects of other hormones and reagents. Moreover, the presence of cycloheximide (10(-6) mol/l), an inhibitor of protein synthesis, completely blocked the enhancement of bone alkaline phosphatase activity by AHZ. These findings suggest that AHZ has an effect different from bone cellular response for other bone-regulating factors, and that bone protein synthesis was a necessary component for AHZ action.