Effect of zinc on bone metabolism in fetal mouse limb culture.

ABSTRACT

OBJECTIVE: To determine the effects of zinc-deficiency and zinc-excess on bone metabolism. METHODS: We developed the culture model of fetal mouse limbs (16th day) cultivated in self-made rotator with continuing flow of mixed gas for six days in vitro. The cultured limbs were examined by the techniques of 45Ca tracer and X-roentgenography. RESULTS: The right limbs cultivated had longer bone length, higher bone density than the left limbs uncultivated from the same embryo; and histologically, the right limbs had active bone cell differentiation, proliferation, increased bone trabecula, clearly calcified cartilage matrix, and osteogenic tissue. Compared with the control group, the zinc-deficient group and zinc-excess (Zn2+ 120 mumol/L) group contained less osteocalcin (BGP) and 45Ca content, and lower AKP activity; whereas zinc-normal (Zn2+ 45 mumol/L and Zn2+ 70 mumol/L) groups contained more BGP and 45Ca contents, and higher AKP (alkaline phosphatase) activity. CONCLUSION: Both zinc-deficiency and zinc-excess can alter bone growth and normal metabolism. The results indicate that the culture model of fetal mouse limbs (16th day) in vitro can be used as a research model of bone growth and development.