title: The effect of lead on the eruption rates of incisor teeth in rats.
abstract: The effects of lead on the continuously erupting rat incisors under normo-, hyper- and hypofunctional conditions were investigated. Left lower incisors of 20 rats were rendered unimpeded (hypofunctional) by cutting them out of occlusion every 2 days; the right lower incisors of these rats were considered hyperfunctional. Measurements on normally growing teeth (normofunctional) were carried out in a group of ten rats whose teeth were not cut but only marked every 2 days. On day 7 of the experiment, half of the rats from these two groups were given a single intraperitoneal injection of lead acetate (40 mg/kg), and the other half received sodium acetate (22 mg/kg). Another group of 15 rats was used to obtain blood samples for lead determination 1 h, and 10, 20, and 30 days after lead administration. Animals were killed on day 32. Hypofunctional incisors from lead-treated rats erupted more slowly than control ones (P<0.05). These results show a previously unreported toxic effect of heavy metals.
authors.affiliation: Departamento de Morfologia, Faculdade de Odontologia de Piracicaba, UNICAMP, Avenida Limeira 901, CEP: 13414-018, SP, Piracicaba, Brazil.
authors.forename: R F
authors.initials: RF
authors.lastname: Gerlach
authors.forename: D B
authors.initials: DB
authors.lastname: Toledo
authors.forename: P D
authors.initials: PD
authors.lastname: Novaes
authors.forename: J
authors.initials: J
authors.lastname: Merzel
authors.forename: S R
authors.initials: SR
authors.lastname: Line
mesh_terms: D000818:Animals; D001835:Body Weight; D003766:Dental Occlusion; D005500:Follow-Up Studies; D007180:Incisor / Q000187:drug effects* / Q000254:growth & development; D007274:Injections, Intraperitoneal; D007854:Lead / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D008297:Male; D009942:Organometallic Compounds / Q000008:administration & dosage / Q000494:pharmacology; D010513:Periodontal Ligament / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D019346:Sodium Acetate / Q000008:administration & dosage / Q000494:pharmacology; D013223:Statistics as Topic; D014078:Tooth Eruption / Q000187:drug effects*
chemical_list: D009942:Organometallic Compounds; D007854:Lead; D019346:Sodium Acetate; C008261:lead acetate