OPG protein levels in MG-63 cells after particle and alpha-CGRP treatment. Time courses of OPG protein levels in MG-63 osteoblast-like cells stimulated by UHMWPE particles and alpha-CGRP using Western blot analysis. (A) Representative Western blot for OPG in untreated group and the alpha-CGRP-incubated groups. Densitometric quantification of OPG in (B) a cell-particle ratio of 1:100 and (C) a cell-particle ratio of 1:500 with and without alpha-CGRP-incubation. OPG protein levels are expressed relatively to GAPDH. Data are reported as mean ± standard deviation (n = 5). ((a) P < 0.05).