Avaliação do efeito inibidor da vitamina C na carcinogenese esofagica experimental induzida pela dietilnitrosamina

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

Cancer is today the second death cause in developed countries. In spite of the fact that certain advances have been obtained in the course of its treatment, the prognosis of this disease is still far from being satisfactory. Although esophageal cancer is not among the most frequent kinds of cancer actually it is the fourth neoplasia to affect man s digestive system - its studies are very important, basically for two reasons: first, this type of cancer affects people in their most natural life proceeding: nutrition; second, its occurrence rates are quite similar to those of mortality, clearly demonstrating the inefficiency of the treatment. However, two procedures may change this terrifying picture: early diagnosis and prevention. So, the search for substances that may interfere with the carcinogenesis keeping away the possibilities of new tumors looks like a very attractive idea. The aim of this report was to evaluate the inhibiting effect of vitamin C in the experimental esophageal carcinogenesis induced by diethylnitrosamine (NDEA). Were employed 240 male Wistar rats, all of them with approximately 155 gr. of weight and three months old. The animals were kept in cages with five rats each and fed with food and water ad libitum. Drugs were dissolved in water. Dosages were: NDEA: 10mg. / kg. / day and vitamin C: 1,290 mg. / kg. / day. The animals were divided into different groups according to the drug/drugs they would be given, for a better study of the drug effects Group I, control, only water, seven days a week; Group II, only vitamin C, seven days a week; Group III, NDEA, three days a week and water, the other four days; Group IV, NDEA, three days a week and vitamin C, the other four days; Group V, NDEA and vitamin C together in the same bottle, three days a week and only water, the other four days; Group VI, NDEA and vitamin C together in the same bottle, three days and vitamin C, the other from days. Every group was subdivided into other smaller groups of ten animals each, according to the observation time (T). The animals were sacrificed in four different times, 90, 120, 150 and 180 days. After the elapsed time, each animal was sacrificed and its esophagus was macro/microscopically evaluated to identify any tumors. As final results, in the groups I and 11 and in T90 and T120 of groups III, IV, V and VI there was no occurrence of any kind of tumor. The macroscopic studies in T 150 showed ten lesions in the group III (0.1 lesion per animal) and seven lesions in the group IV (0.7 lesion per animal), and no lesion the in the groups V and VI. The microscopic studies showed six lesions in the group III (O.6Iesion per animal) and five lesions in the group IV (OA lesion per animal), and no lesion in the groups V and VI. The macroscopic studies in T180 showed 48 lesions in the group III (4.8 lesions per animal), 31lesions in the group IV (3.1IesiolÍs per animal), 5 lesions in the group V (0.5 ,lesion per animal) and only one lesion in the group VI (0.1 lesion per animal). the microscopic studies identified 23 lesions in the group III (2.3 lesions per animal), 17 lesions in the group IV (1.7 lesions per animal), 3 lesions in the group V (0.3 lesion per animal) and only one lesion in the group VI (0.1 lesion per animal). The analysis of such results shows that there were significant differences among the groups towards the occurrence of tumors. On the other hand, group III was the one that showed the highest rate of neoplasias. Therefore, the analysis of the results demonstrated that vitamin C administered together with diethylnitrosamine (NDEA) showed an inhibiting effect over the occurrence of tumors in animals

ASSUNTO(S)

esofago - doenças antioxidantes vitamina c

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