The effect of lead on the eruption rates of incisor teeth in rats.
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.
Gerlach
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RF
Departamento de Morfologia, Faculdade de Odontologia de Piracicaba, UNICAMP, Avenida Limeira 901, CEP: 13414-018, SP, Piracicaba, Brazil.
Toledo
D B
DB
Novaes
P D
PD
Merzel
J
J
Line
S R
SR
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*
D009942:Organometallic Compounds; D007854:Lead; D019346:Sodium Acetate; C008261:lead acetate