The effect of desalivation on 4-nitroquinoline-1-oxide-induced tongue carcinogenesis: a morphometric study of nucleolar organizer regions

Citation
I. Kaplan et al., The effect of desalivation on 4-nitroquinoline-1-oxide-induced tongue carcinogenesis: a morphometric study of nucleolar organizer regions, J ORAL PATH, 30(1), 2001, pp. 48-52
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
JOURNAL OF ORAL PATHOLOGY & MEDICINE
ISSN journal
0904-2512 → ACNP
Volume
30
Issue
1
Year of publication
2001
Pages
48 - 52
Database
ISI
SICI code
0904-2512(200101)30:1<48:TEODO4>2.0.ZU;2-7
Abstract
Saliva is an important factor in the oral cavity and could be significant i n protecting against carcinogens. In experimental models of carcinogenesis, saliva was shown to have a temporary protective effect against the carcino gens DMBA and 4-nitroquinoline-oxide (4NQO). Silver-stained nucleolar organ izer regions (AgNORs) are considered markers for both proliferative capacit y and prognosis. The purpose of the present study was to investigate the ef fect of desalivation on AgNOR parameters in lesions induced by the carcinog en 4NQO in a rat model, in order to trace early nuclear changes. The study group consisted of 120 male Wistar-derived rats. The experimental group (n= 56) underwent surgical desalivation; the control group (n=56) underwent a s ham operation, and both groups were administered a solution of 0.001% 4NQO in the drinking water. A normal group (n=8) did not receive surgery and dra nk tap water. Rats were sacrificed at 7, 14, 22, and 28 weeks. Formalin fix ed, paraffin embedded sections of the tongue were silver-stained and AgNOR parameters were analyzed using computerized image analysis. In both desaliv ated and control groups, the nuclear area was significantly higher than the normal. This difference was already evident at 7 weeks. The mean AgNOR are a was significantly higher in the desalivated group at week 7 and continued to increase over time. The mean AgNOR number was also significantly higher in the desalivated group at week 7. Differences between the desalivated an d control groups diminished with time. These changes in proliferative activ ity, as expressed by AgNOR parameters, presented earlier changes in compari son to those observed in microscopic examination of the same slides. Result s suggest that saliva in the oral cavity can de lay malignant transformatio n, but continued exposure to the carcinogen overrides this effect. AgNOR st ain seems to be sensitive and allows for early identification of intranucle ar changes.