Naloxone hydrochloride

2-AP, glutamate, and MK-801 were purchased from Sigma (St. Louis, MO, USA). Formaldehyde 37% (Vetec, Brazil), morphine hydrochloride (Vetec, Brazil), caffeine (Merck, USA), and naloxone hydrochloride (Cristália, Brazil) were also purchased and used in this study. All drugs were diluted in distilled water except 2-AP which required Tween 80 and distilled water. The other solvents and chemicals used in this study were purchased from Sigma-Aldrich® (São Paulo, São Paulo, Brazil).

The following drugs and reagents were acquired in Sigma-Aldrich® (St. Louis, MO, United States): 5-fluorouracil (5-FU), diazepam, naloxonazine, cyclophosphamide, and Tween 80. The anesthetics ketamine and xylazine were obtained from Konig S.A. (Brazil), and MSD Saúde Animal (Brazil), respectively. Other drugs, reagents, and kits comprise: heparin (HEPAMAXS®), ELISA Kit (eBioscience®, Inc. Science Center Drive, San Diego, CA, United States), kits for hematological and biochemical analysis (LABTEST; Lagoa Santa, MG, Brazil), morphine hydrochloride (Merck®), naloxone hydrochloride (Cristália®), formaldehyde 37% (Vetec), dimethylsulfoxide - DMSO (Mallinckrodt Chemicals - Phillipsburg, NJ, United States). The acridine derivative N’-(6-chloro-2-methoxy-acridin-9-yl)-2-cyanoacetohydrazide (ACS-AZ) was synthesized as previously described (Silva et al., 2018 (link)).

The following materials were used: acetic acid and absolute ethyl alcohol (Neon, São Paulo, Brazil), L-glutamic acid (glutamate) (Vetec, Rio de Janeiro, Brazil), capsaicin, cinnamaldehyde, indomethacin (Sigma-Aldrich, St. Louis, MO, USA), ketamine hydrochloride, xylazine hydrochloride (Syntec, São Paulo, Brazil), naloxone hydrochloride (Cristália, São Paulo, Brazil), formalin (Dinâmica, São Paulo, Brazil), sodium hydroxide (Nuclear, São Paulo, Brazil), menthol (A Essência, Santa Catarina, Brazil), and tween 80 (Labsynth, São Paulo, Brazil). The drugs were dissolved in 0.9% NaCl solution (saline) before administration, except cinnamaldehyde (1% tween 80 in saline), glutamate (saline solution at pH 7), and menthol (1.6% absolute ethyl alcohol + 0.01% tween 80 in saline). capsaicin was prepared from a 0.5% capsaicin stock solution dissolved in absolute ethyl alcohol, and the 0.1% solution was prepared at the time of use by mixing the stock solution with tween 80 and 2:1:7 saline solution.