title: Potentiation of methylmercury toxicity by piperonyl butoxide.
abstract: Methylmercury (MeHg) is an extremely potent neurotoxin about 25% of which is degraded in vivo to inorganic mercury. Piperonyl butoxide (PB) is a widely used pesticidal synergist which inhibits many mammalian detoxification reactions. In a preliminary experiment with the high doses of PB and MeHg, PB induced a 12% decrease in mean survival time and a 20% decrease in mean latency time to neurotoxicity. The weight loss in PB-MeHg group was far greater than the control MeHg group. In a dose response experiment, mean survival times in rats fed 40 ppm MeHg-C1 were 5.75, 5.3, and 5.0 weeks at 0, 0.5, and 1% PB, respectively. By the ninth week 25% of rats fed 20 ppm MeHg-C1 showed neurotoxicity and 63% of the 0.5% PB fed showed neurotoxicity with some mortality. In experiments at 20 ppm MeHg-C1 both  PB fed groups weighted considerably less than corresponding controls.
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D004357:Drug Synergism; D008297:Male; D008767:Methylmercury Compounds / Q000633:toxicity*; D010882:Piperonyl Butoxide / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors
chemical_list: D008767:Methylmercury Compounds; D010882:Piperonyl Butoxide