[The effects of platelet-derived growth factor-AA on the osteoclasts].

OBJECTIVE: To study the effects of platelet-derived growth factor (PDGF)-AA on the osteoclasts. METHODS: The PDGF receptor alpha (PDGFR-alpha) was detected on the osteoclastic membrane with immunoelectronmicroscopy. Acid phosphatase (ACP) and tartrate-resistant acid phosphatase (TRAP) activities were measured kinetically and the introcellular hydrogen ions were calculated on the confocal laser scanning microscope (CLSM) stained with SNAFL. Stained by toluidine blue, the area and number of the resorption pits were determined with the Leica Quantimet 500 system. RESULTS: The colloidal gold precipitated on the cellular membrane, and the TRAP activity had no difference (P > 0.05). Hydrogen ions rose significantly but their release could not be promoted by PDGF-AA. The changes of the resorption pits were not significant. CONCLUSIONS: The PDGF-AA could promote hydrogen ions yielding but not stimulate osteoclastic bone resorption due to the significant TRAP changes of TRAP activities.