Abstract
The capability of β-alanyl-L-histidinato zinc (AHZ) to increase alkaline phosphatase activity in the femoral diaphysis from elderly rats was investigated. The femoral-diaphyseal tissues were removed from weanling (3-week-old) and elderly (10-month-old) female rats. Bone tissues were cultured in Dulbecco's modified Eagle medium (high glucose, 4.5%) supllemented with antibiotics and bovine serum alubumin. Among various other bone-stimulating factors (AHZ ; 10-5M, zinc sulfate ; 10-4M, sodium fluoride ; 10-3M, insulin ; 10-8M, and β-estradiol ; 10-9M), AHZ had a potent effect on increasing alkaline phosphatase activity in the diaphyseal tissues from both rat groups. In the bone tissues from elderly rats, the effect was concentration dependent (10-7-10-5M). At 10-5M the effect of AHZ was seen for a longer time during 72-h culture, although the zinc sulfate (10-5M) effect was no longer. The effect of AHZ to increase bone alkaline phosphatase activity was completely abolished by the presence of cycloheximide (10-6M). AHZ thus appears able to directly stimulate alkaline phosphatase activity dependent on protein synthesis in the bone tissues from elderly rats.
