An aromatase inhibitor and tamoxifen decrease plasma levels of o,p'-DDT and its metabolites in Nile tilapia (Oreochromis niloticus).
The objective of this study was to determine if tamoxifen or an aromatase inhibitor (4-hydroxyandrostenedione; 4-OHA) affected plasma concentrations of o,p' -DDT and its metabolites, o,p'-DDD and o,p'-DDE, in mature tilapia. Male and female tilapia were injected 6 times intraperitoneally with o,p'-DDT (40 mg/kg) alone or in combination with 4-OHA (2 mg/kg) over a 12 day period. An additional group of male fish was injected with tamoxifen (5 mg/kg) plus o,p'-DDT. At the end of the treatment period, plasma samples were extracted and analyzed by GC/ECD. Females injected only with o,p'-DDT had significantly higher levels of o,p'-DDT compared with males. Interestingly, females and males treated concomitantly with o,p'-DDT and 4-OHA or tamoxifen had significantly lower concentrations of plasma o,p'-DDT (about 50%) compared with fish treated with only o,p'-DDT. These initial results suggest that an interaction between endocrine-active compounds occurs in vivo in tilapia and may involve alterations in metabolism of o,p'-DDT.
Leaños-Castañeda
Olga
O
Departamento de Recursos del Mar, CINVESTAV Unidad Mérida, Carretera Antigua a Progreso km. 6, Ap. Postal 73 "Cordemex", Mérida, Yucatán 97310, México.
Gold-Bouchot
Gerardo
G
Van Der Kraak
Glen
G
Lister
Andrea
A
Ceja-Moreno
Victor
V
Simá-Alvarez
Raul
R
D000735:Androstenedione / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D047072:Aromatase Inhibitors; D001711:Biotransformation / Q000187:drug effects; D002849:Chromatography, Gas; D023681:Cichlids / Q000097:blood*; D003634:DDT / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D005260:Female; D008297:Male; D012737:Sex Factors; D013629:Tamoxifen / Q000494:pharmacology*
D047072:Aromatase Inhibitors; D013629:Tamoxifen; D000735:Androstenedione; D003634:DDT; C016340:o,p'-DDT; C014594:formestane