Effects of NGF on CGRP expression. (A) NGF deprivation. Using real-time PCR the effects of anti-NGF antibody treatment on CGRP expression were evaluated in LPS-stimulated monocytes after 24 hours of culture. The induction of CGRP expression as a response to LPS (LPS) is abolished by anti-NGF treatment (LPS+abNGF) and is comparable to the basal CGRP expression found in unstimulated monocytes (Us). No similar effect was obtained when using isotypic IgG (LPS+IgG). The results are expressed as fold increase in arbitrary units and represent the mean plus or minus the standard error of the mean (SEM) of 3 independent experiments, each performed in triplicate. (LPS vs Us and LPS+aNGF vs LPS+IgG, ^*P < .01 according to Tukey-Kramer test). (B) NGF addition. Ethidium bromide staining of RT-PCR-amplified CGRP gene transcripts of unstimulated (Us) and LPS-stimulated human monocytes (LPS) treated for 24 hours with 100 ng/mL NGF. These ethidium bromide-stained gels are representative of 4 independent experiments.