title: Toxicity to heavy metals and relationship to seizure thresholds.
abstract: The present study was designed to provide information on the effects of lead, mercury, and nickel on lethality, body weight, and brain excitability in the adult rat. Both short- (2 days) and long-term (6 wk) drug administrations were carried out in adult male albino rats (Sprague-Dawley, Zivic-Miller). Based on the mg/kg/day of drug given over a 2-day period, the LD50 values were as follows: Pb(Ac)2, 215; Pb(NO3)2, 65.9; MMC, 11.9; HgCl2, 4.5; Ni(Ac)2, 35-40; NiSO4, 35-40. High doses of each of the metals administered acutely caused a drop in body weight but had an inconsistent effect on flurothyl-induced seizure thresholds. Pb(Ac)2, 200 mg/kg/day for 2 days, produced a statistically significant anticonvulsant effect, while 50 mg/kg Pb(NO3)2 resulted in a fall in threshold. Both NiSO4 and Ni(Ac)2, 30 mg/kg, increased seizure threshold. Neither the organic nor inorganic mercury altered thresholds. Long-term administration of Pb(Ac)2, MMC, or HgCl2 resulted in marked effects on body weight but no significant change in brain excitability.
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007854:Lead / Q000633:toxicity*; D007928:Lethal Dose 50; D008297:Male; D008628:Mercury / Q000633:toxicity*; D009532:Nickel / Q000633:toxicity*; D051381:Rats; D012640:Seizures / Q000139:chemically induced*; D013997:Time Factors
chemical_list: D007854:Lead; D009532:Nickel; D008628:Mercury