Dyes, Peptides, and Antagonists in Neurological Studies

Evans blue dye (50 mg/ml saline; Sigma-Aldrich, St. Louis, MO, United States), human calcitonin gene-related peptide (CGRP; 1 mg/ml saline; Bachem, Torrance, CA, United States; a 37-amino acid peptide), and α-CGRP 8-37 (1 mg/ml distilled water, Bachem, Torrance, CA, United States; a CGRP receptor antagonist) were used in this study (Shen et al., 2001 (link)). Substance P acetate salt hydrate (SP; 0.5 mg/ml saline; Sigma-Aldrich; a SP receptor agonist) and (+)-(2S,3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine (CP-99994; 33 mmol/ml saline; Sigma-Aldrich; an SP receptor antagonist) were also used (McLean et al., 1993 (link)). Resiniferatoxin (RTX; 100 μg/ml vehicle; Sigma-Aldrich), an ultrapotent Capsaicin analog known to block small diameter afferent fibers containing transient receptor potential vanilloid type 1 receptor (TRPV1) (Suter et al., 2009 (link)), was dissolved in a vehicle that contained 0.3% Tween 80, 10% DMSO and saline. Capsaicin (0.05 and 0.1%; Sigma-Aldrich; a TRPV1 agonist) was dissolved in a vehicle consisting of 10% alcohol and 10% Tween 80 in saline (Knotkova et al., 2008 (link)), and FITC-conjugated isolectin B4 (FITC IB4 tracer; 1%, 3 μl, Vector Laboratories, Burlingame, CA, United States) was used.