AN ASSESSMENT OF POSSIBLE PROTECTIVE ROLES OF MORPHINE AND NALOXONE ON THE ACUTE TOXICITY OF T-2 TOXIN

The efficacy of naloxone and morphine on acute toxicity of T-2 toxin, a potent cytotoxic trichothecene mycotoxin, was investigated. In this study, mice received naloxone (4 or 8 mg/kg, sc) or morphine (5 or 15 mg/kg, sc) 24, 18, 1 hr before and 6 hr after ip injection of 2 or 1.8 mg/kg of T-2 toxin, respectively. In addition, naloxone (8 mg/kg, sc) were administered at 13, 7, 1 hr before, and 5 hr after T-2 toxin adm inistration (1.8 mg/kg, ip). The acute lethal toxicity and change in b ody and organ weights (including liver, spleen, and kidneys) were eval uated. The acute lethal toxicity of T-2 toxin was reduced by administr ation of the first regimen of naloxone (8 mg/kg, sc). It also caused a protective effect against T-2 toxin-induced weight changes. On the ot her hand, morphine increased T-2 toxin-induced lethality (although not statistically significant). It could be concluded that opioid agonist s may exacerbate the lethal toxicity of T-2 toxin-induced shock and op ioid antagonists such as naloxone could antagonize this shock.