CGRP assay
Firstly, affinity sorbent (A19482, SPI Bio, Bertin Pharma) was used with
a pool of different sources of plasma to prepare CGRP-free plasma. Then,
the samples were analyzed using a commercially available kit by
following the manufacturer’s procedures: CGRP (A05482, SPI Bio, Bertin
Pharma). The concentration of CGRP is measured using Ellman’s Reagent to
detect the enzymatic activity of the AChE. The intensity of the yellow
color formed is proportional to the amount of CGRP present in that
sample [11]. The absorbance was read at 405 nm on SpectraMax I3
(Molecular Devices, San Jose, California, USA). The absorbance values of
the standards were used to plot a standard curve, from which absorbance
values of experimental samples were interpolated to determine their
concentrations. The sensitivities of the assay were 2 pg/ml using
quality control. This test was performed in mice plasma of 7th-day
post-stress induction.