In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) affects tooth development in rhesus monkeys.
We thought to validate the current tolerable daily intake (TDI) value for dioxin (4 pg/kg) in Japan. Pregnant rhesus monkeys received an initial dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 0, 30, or 300 ng/kg subcutaneously) on day 20 of gestation; the dams received additional injection of 5% of the initial dose every 30 days until day 90 after delivery. The teeth of stillborn, postnatally dead, and surviving offspring (now approximately 4 years old) were evaluated. None of the offspring in the 0 and 30 ng/kg groups (n=17 and 15, respectively) had tooth abnormalities, whereas 10 of 17 in the 300 ng/kg had them. These findings suggest the lowest-observed adverse-effect level (LOAEL) for TCDD in the rhesus monkey is between 30 and 300 ng/kg, and probably is close to that for rodents (86 ng/kg) on which the current TDI was based. It is reasonable to conclude that the current TDI needs no immediate modification.
Yasuda
Iku
I
Department of Advanced Prosthodontics, Division of Cervico-Gnathostomatology, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8553, Japan.
Yasuda
Mineo
M
Sumida
Hiroshi
H
Tsusaki
Hideshi
H
Arima
Akihiro
A
Ihara
Toshio
T
Kubota
Shunichiro
S
Asaoka
Kazuo
K
Tsuga
Kazuhiro
K
Akagawa
Yasumasa
Y
D000014:Abnormalities, Drug-Induced; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008253:Macaca mulatta; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D014070:Tooth / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development; D014071:Tooth Abnormalities / Q000139:chemically induced* / Q000196:embryology; D018675:Toxicity Tests
D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins