TY - JOUR
T1 - Hepatic DNA adduct dosimetry in rats fed tamoxifen
T2 - A comparison of methods
AU - Schild, Laura J.
AU - Phillips, David H.
AU - Osborne, Martin R.
AU - Hewer, Alan
AU - Beland, Frederick A.
AU - Churchwell, Mona I.
AU - Brown, Karen
AU - Gaskell, Margaret
AU - Wright, Elizabeth
AU - Poirier, Miriam C.
N1 - Funding Information:
We thank I.R.Hardcastle, Institute for Cancer Research, Sutton, UK for synthesizing the α-hydroxy-TAM. This study was supported by Cancer Research UK, and the intramural research programs of the National Center for Toxicological Research and the National Cancer Institute, NIH.
PY - 2005/3
Y1 - 2005/3
N2 - Liver homogenates from rats fed tamoxifen (TAM) in the diet were shared among four different laboratories. TAM-DNA adducts were assayed by high pressure liquid chromatography-electrospray tandem mass spectrometry (HPLC-ES-MS/MS), TAM-DNA chemiluminescence immunoassay (TAM-DNA CIA), and 32P- postlabeling with either thin layer (32P-P-TLC) or liquid chromatography (32P-P-HPLC) separation. In the first study, rats were fed a diet containing 500 p.p.m. TAM for 2 months, and the values for measurements of the (E)-α-(deoxyguanosin-N2-yl)-tamoxifen (dGr-N2-TAM) adduct in replicate rat livers varied by 3.5-fold when quantified using 'in house' TAM-DNA standards, or other approaches where appropriate. In the second study, rats were fed 0, 50, 250 or 500 p.p.m. TAM for 2 months, and TAM-DNA values were quantified using both 'in house' approaches as well as a newly synthesized [N-methyl-3H]TAM-DNA standard that was shared among all the participating groups. In the second study, the total TAM-DNA adduct values varied by 2-fold, while values for the dG-N 2-TAM varied by 2.5-fold. Ratios of dG-N2-TAM:(E)-α- (deoxyguanosin-N2-yl)-N-desmethyltamoxifen (dG-N2-N- desmethyl-TAM) in the second study were ∼1:1 over the range of doses examined. The study demonstrated a remarkably good agreement for TAM-DNA adduct measurements among the diverse methods employed.
AB - Liver homogenates from rats fed tamoxifen (TAM) in the diet were shared among four different laboratories. TAM-DNA adducts were assayed by high pressure liquid chromatography-electrospray tandem mass spectrometry (HPLC-ES-MS/MS), TAM-DNA chemiluminescence immunoassay (TAM-DNA CIA), and 32P- postlabeling with either thin layer (32P-P-TLC) or liquid chromatography (32P-P-HPLC) separation. In the first study, rats were fed a diet containing 500 p.p.m. TAM for 2 months, and the values for measurements of the (E)-α-(deoxyguanosin-N2-yl)-tamoxifen (dGr-N2-TAM) adduct in replicate rat livers varied by 3.5-fold when quantified using 'in house' TAM-DNA standards, or other approaches where appropriate. In the second study, rats were fed 0, 50, 250 or 500 p.p.m. TAM for 2 months, and TAM-DNA values were quantified using both 'in house' approaches as well as a newly synthesized [N-methyl-3H]TAM-DNA standard that was shared among all the participating groups. In the second study, the total TAM-DNA adduct values varied by 2-fold, while values for the dG-N 2-TAM varied by 2.5-fold. Ratios of dG-N2-TAM:(E)-α- (deoxyguanosin-N2-yl)-N-desmethyltamoxifen (dG-N2-N- desmethyl-TAM) in the second study were ∼1:1 over the range of doses examined. The study demonstrated a remarkably good agreement for TAM-DNA adduct measurements among the diverse methods employed.
UR - http://www.scopus.com/inward/record.url?scp=21044450818&partnerID=8YFLogxK
U2 - 10.1093/mutage/gei015
DO - 10.1093/mutage/gei015
M3 - Article
C2 - 15755801
AN - SCOPUS:21044450818
SN - 0267-8357
VL - 20
SP - 115
EP - 124
JO - Mutagenesis
JF - Mutagenesis
IS - 2
ER -