| Objective: In this paper we investigated whether the advanced glycosylate end products(AGE) could activate the bone resorption function of osteoclasts in vitro and explored its mechanisms in order to obtain the direct evidences of AGE involved in the processes of bone metabolism and the development of osteoporosis. Methods: The human AGE proteins were prepared by incubating human serum albumin and glucose in constant temperature and determined by fluorescence spectrophotometer. The osteoclasts were isolated from human iliac spongy bone with collagenase II and purified on the basis of the difference of the attachment velocity. The isolated osteoclasts were identified by the observation of cell modality, histochemical and immuno-electromicroscopy analysis of tartrate- resistant acid phosphatase as well as immunofluorescence determination of vitronectin receptor. The tartrate-resistant acid phosphatase activity and the intracellular H~ measurement were carried out to evaluate the effects of AGE on osteoclasts. The area and number of the resorption pits were also measured on the Leica Quantimet 500 system stained with toluidine blue. Results: The formation of AGE were found to be both positive glucose dose- and time-dependent. The osteoclast isolation procedure conducted were proved to be feasibility and the typical characteristics of osteoclast were positive. Lower dose of AGE can induce increment of the intracellular H~ of osteoclasts(p<0.05) and the effect was dose- 4 dependent, but the changes of ACP and TRACP were little and the resorption pits modified with no difference. Higher dose of AGE can significantly increase ACP and TRACP activity of the osteoclasts (p< 0.01) and effectively enhance the formation of bone resorption pits(p<0.05). Conclusion: AGE can promote acidification in osteoclasts and accelerate the bone resorption function of osteoclast in vitro, suggested that AGE maybe the common etiological basis of geratic and diabetic osteoporosis.
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