Determination of acute toxicity parameters of the drug ‘MEGASTOP for dogs’ on white rats and mice

Abstract

The experiments were performed on 58 males of nonlinear white rats 3–4 months old and weighing 180–200 g and 64 females of nonlinear white mice 2.5–3 months old and weighing 18–22 g. In the main experiment on rats, six experimental groups were formed, the animals of which were injected intragastrically with the drug ‘MEGASTOP for dogs’ (by absolute weight) in doses of 1,000.0, 2,000.0, 3,000.0, 4,000.0, 5,000.0, and 6,000.0 mg/kg body weight; in the main experiment on mice, seven experimental groups were formed, the animals of which were administered the drug in doses of 100.0, 500.0, 1,000.0, 1,500.0, 2,000.0, 2,500.0, and 3,000.0 mg/kg body weight. Control rats and mice were injected with 2.0 cm3 and 0.2 cm3 of polyethylene glycol-400, respectively. Clinical symptoms of poisoning with the drug ‘MEGASTOP for dogs’ of white rats (at doses of 2,000.0–6,000.0 mg/kg body weight) and mice (at doses of 1,000.0–3,000.0 mg/kg body weight) were refusals of food and water, loss of coordination, sitting in one place, a dose-dependent increase in depression with subsequent complete depression, lack of response to external stimuli and death on the first or fourth day after administration. During autopsy in rats and mice that died as a result of poisoning with the drug ‘MEGASTOP for dogs’, we recorded pallor of the mucous membranes of the mouth, trachea, pharynx, and esophagus; increase in heart volume, atrial blood supply; pulmonary hyperemia; uncoagulated blood; increase in liver volume, dark cherry color, flabby consistency; catarrhal inflammation of the mucous membrane of the small intestine. According to the results of determining the parameters of acute toxicity of the drug ‘MEGASTOP for dogs’ in the case of a single intragastric injection, LD50 for male rats is 3,384.98 ± 444.94 mg/kg, and for female mice — 2,025.88 ± 279.46 mg/kg body weight, which allows to classify it to class IV by the toxicity — low-toxic substances (LD50 — 501–5,000 mg/kg) and by the degree of danger to class III— moderately dangerous substances (LD50 — 151–5,000 mg/kg)