Fig. 4.

CGRP temporarily augments particle- and LPS-induced OPG secretion in MG-63 osteoblasts cultured alone. THP-1 macrophage-like cells co-cultured with MG-63 osteoblasts were stimulated with LPS or UHMWPE particles. The effects of CGRP (10⁻⁸ M) treatment on co-cultured cells were analyzed. OPG secretion, as normalized to the unstimulated control, of co-cultures and controls activated by a high levels of LPS (100 ng/ml) or b UHMWPE (cell-to-particle ratio of 1:500) for 6 h of incubation as compared to the respective OPG fold secretion of activated cells treated with the neuropeptide CGRP. *p < 0.05; **p < 0.01