Linked Life Data

2119250

Source:http://linkedlifedata.com/resource/pubmed/id/2119250

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1990-10-19
pubmed:abstractText
Pregnancy and development are known to modify carcinogenesis. Little is known about the mechanism for the modulation. These studies investigated the relative sensitivity of nonpregnant, pregnant, and fetal mice to the induction of covalent DNA modifications and micronucleated erythrocytes by 4-nitroquinoline 1-oxide (4-NQO). Our results revealed that 4-NQO was bound to guanine nucleotides of DNA in all maternal and fetal organs tested. The adduct levels ranged from 2-60 base modifications per 10(9) DNA bases when 4-NQO was administered s.c. Overall, 4-NQO bound preferentially to DNA of the maternal tissues compared with that of the corresponding fetal tissues, with the exception of the liver. The adduct levels in maternal and fetal organs fell into 3 distinct levels. The greatest binding was in maternal lungs and pancreas (the target organs for carcinogenesis). The lowest binding levels were in maternal liver and all fetal organs studied. Gestation age at the time of 4-NQO treatment did not produce a significant effect on the amounts of adduct formation in the tissues examined, with the exception of placenta and bone marrow. Chronic treatment did not affect binding preference. At the cellular level, 4-NQO treatment induced twice the frequency of micronucleated erythrocytes in the bone marrow of pregnant mice compared with the nonpregnant mice and fetal liver, on a mg/kg basis. However, the polychromatic erythrocytes of fetal liver were more sensitive than those of adult bone marrow to the induction of micronuclei, when adduct levels were taken into account. A positive correlation of organotropsim between 4-NQO-induced DNA adducts and carcinogenicity was observed for maternal tissues, but not for fetal tissues. Fetal tissues, overall, lack the enzymes to metabolically activate 4-NQO. Fetal cells elicit greater biological responses, compared with adult cells, at equal adduct levels. This study reveals that the effective doses in maternal and fetal tissues may differ and, therefore, will be a better basis for further understanding the molecular mechanism of transplacental carcinogenesis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6192-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Induction of covalent DNA modifications and micronucleated erythrocytes by 4-nitroquinoline 1-oxide in adult and fetal mice.
pubmed:affiliation
Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston 77550.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.