Effects of coenzyme Q10 and N-acetylcysteine on experimental poisoning by paracetamol in Wistar rats.

Paracetamol (PAR) is a drug widely used in human and veterinary medicine as an analgesic and antipyretic, often involved in cases of intoxication. The most common clinical signs result from damage to red blood cells and hepatocytes, and this intoxication is considered a model for the induction of acute liver failure. In the present study, the hepatoprotective effects of coenzyme Q10 (CoQ10) and N-acetylcysteine (NAC) against experimental paracetamol (PAR) poisoning were analysed. Thirty-five adult Wistar rats (Rattus novergicus albinus) were randomly assigned to five groups, and thirty-one of these survived the treatments. Negative control group (CON-) received 1mL of 0.9% NaCl orally (PO). Other groups received 1.2g/kg of PAR (PO). Positive control group (CON+) received only PAR. NAC group received 800 mg/kg intraperitoneally (IP) of NAC 1h after the administration of PAR and at 12 h received 1mL of 0.9% NaCl, IP. The fourth group (CoQ10) received 1h and 12 h after intoxication, CoQ10 (10mg/kg IP). And the fifth group (NAC+CoQ10) received NAC (800mg/kg, IP) and CoQ10 (10mg/kg, IP). After 12 hours, the rats were euthanized and necropsied to collect liver and kidney tissues for histopathological evaluation and electronic microscopy. A single dose of PAR caused severe acute hepatitis. NAC couldn't reverse the liver and kidney damages. The group that received CoQ10 and NAC had moderate liver damage, while the group that received only CoQ10 had lower values of liver enzymes and mild liver and kidney damage. Animals that received treatment with CoQ10 or NAC+CoQ10 presented normal hepatocyte mitochondria and nuclei. Although CoQ10 couldn't reverse PAR organ damage, results indicate promising hepatoprotection in Wistar rats.

Fatal metaldehyde poisoning in a dog confirmed by gas chromatography.

BACKGROUND: Metaldehyde is a toxic pesticide used mainly as a molluscicide, responsible for intoxication and deaths in both humans and animals. Accidental exposure to metaldehyde in dogs is considered rare, but severe. Data concerning clinical and veterinary forensic toxicology are largely incomplete, especially regarding case reports in dogs. The present work reports a complete and detailed description of a case from the history, clinical evolution, pathological exams and toxicological diagnosis in an accidental case of metaldehyde poisoning in dog. CASE PRESENTATION: An eleven-month-old, 3.0 kg, male German Spitz was presented for emergency care with acute vomiting and seizures 3 hours after suspected accidental ingestion of commercial molluscicide containing 3% metaldehyde (Lesmax®). The animal was in lateral recumbency and showed stuporous mentation, salivation, tonic-clonic status epilepticus, systemic tremors, bilateral miosis, absent palpebral, corneal, oculovestibular and gag reflexes, severely depressed spinal reflexes, dyspnea and tachycardia. Despite treatment, the patient progressed to comatose mentation and died. Necropsy examination revealed discrete lesions in the liver and central nervous system, while stomach examination revealed content of feed, activated charcoal and blue-green granules, compatible to the commercial formula of metaldehyde. Histology examination revealed extensive hemorrhage and severe centrolobular necrosis of the liver and tumefaction of Kupfer cells. Brain samples showed discrete hemorrhage and hyperemia. In order to confirm the diagnosis, samples from feces, stomach content, spleen, liver, heart, kidneys and brain were submitted gas chromatography analysis. Results confirmed the presence of metaldehyde in all samples. We describe clinicopathological abnormalities of a fatal case of metaldehyde poisoning in a dog, as well as postmortem diagnosis using gas chromatography. CONCLUSION: Metaldehyde poisoning is rarely reported, since the diagnosis is often difficult and the notifications scarce. To our knowledge, this is the first report describing clinical signs, pathological findings and chromatographic diagnosis. This report aims to contribute to the understanding of the pathogenesis of metaldehyde intoxication, to further explore veterinary forensic toxicology diagnosis.