| Abstract: | Acute toxicity of diphenylhydantoin (DPH) was studied in 241 male albino rats aged 7, 12, 18, 25 and 90 days. Single intraperitoneal dose of DPH (from 200 to 1000 mg/kg) induced only ataxia and loss of righting reflex in 25-day-old and adult rats. In rats aged 18 days or less ataxia of hindlimbs was also marked. In all these age groups generalized convulsions appeared; they were formed by wild running followed by a clonic phase. The dose of DPH necessary for elicitation of seizures was lowest in 7-day-old rats (75 mg/kg) and increased with age up to 200 mg/kg in 18-day-old rats. The 1000 mg/kg dose was lethal for 25- and 12-day-old rats, but not for 7-day-old ones. The uneven development of excitatory and inhibitory action of DPH is suggested. |
