[A 13-week subacute oral toxicity study of 6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl) amino] benzoate dimethanesulfonate (FUT-187) in dogs.

A subacute oral toxicity study of 6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl) amino] benzoate dimethanesulfonate (FUT-187), a new protease-inhibiting agent, was carried out in beagle dogs of both sexes. FUT-187 was administered to dogs at daily oral doses of 15, 50 and 150 mg/kg. Dogs in 150 mg/kg group were given twice a day in a.m. and p.m.. The results were as follows: 1. Changes of physical sign attributed to FUT-187, consisted of vomiting, diarrhea, salivation, decrease of locomotor activity, sedation and hyperemia of eye mucosa. These changes expect vomiting vanished within about 2 hours after treatment. One male given 150 mg/kg died on day 19 and two females given 150 mg/kg were sacrificed on day 55 and 67 due to deterioration of systemic conditions. 2. Body weight gain was suppressed in males given 150 mg/kg and females given 50 mg/kg or more. 3. In hematological examinations, some changes suggesting anemia or inflammation were observed in a few animals received 50 mg/kg or more 4. In serum biochemical examinations, dogs given 50 mg/kg or more had decrease of albumin, total protein, A/G ratio and total cholesterol, increase of GPT activity. In liver function test, decrease of function was observed in a few animals in 150 mg/kg group. These changes diminished by the end of recovery period. 5. In autopsy findings, ulcer formation and desquamation of mucosa in the digestive tract were observed in dead or sacrificed animals and survived animals given more than 50 mg/kg. In sacrificed animals, liver was yellow in color and intussusception was seen. 6. Plasma levels of intact FUT-187 and metabolites on the day 37 or 83 were higher than that on the first day of administration. 7. In histopathological examinations, ulcer formation, desquamation, degeneration and/or atrophy of mucosa in the digestive tract were observed in the animals from 50 mg/kg and 150 mg/kg groups. In addition, fatty deposition in hepatocytes was observed in one dead animal and two sacrificed animals.(ABSTRACT TRUNCATED AT 400 WORDS)