Figure 4: Tyrosine phosphorylation of NR2B took part in chronic migraine through CGRP in rats after 24 hours of treatment. Western blots of NR2B-pTyr and CGRP showed that treatment with genistein decreased expression of CGRP (c) and NO release (d). Treatment of recombinant CGRP increased the expression of CGRP (c) and NO release (d) but did not improve NR2B-pTyr levels. The level of NO was tested by the nitric acid reductase method. for each group. versus CM-vehicle; versus CM-genistein (300 ng/g)-vehicle.