| Selenium is an essential trace element to animal and human nutrition. Its functions include improving immunity, resisting free radicals, postponing aging, detoxification from some poisionous elements, repressing cancers, and avoiding some regional epidemics etc. Selenium deficiency or potential deficiency is very common with certain extent in the world. In China, about 70% of the territory is short of Se with different extent. In recent years, epidemiological research and interferential experiment indicate that Se deficiency shows positive correlation with tumor occurrence. Therefore, effect and mechanism study of Se on tumor has become an international hotspot investigation.In this experiment, Se-enriched malt was used as selenium sources, and its effect on the progress of hepatocarcinogenesis induced by diethylnitrosamine in rats was studied and its immunohistochemistry study on Proliferating cell nuclear antigen (PCNA) and microvessel density were especially investigated.Test I Effect of selenium-enriched malt on the hepatocarcinogenesis induced by diethylnitrosamine in rats. The effect of selenium-enriched malt on the process of experimental hepatocarcinogenesis induced by diethylnitrosamine (DEN) in rats were observed. One hundred and eighty-five healthy male SD rats weighted 120~150g were randomly divided into five groups. Twenty-five rats in group I were fed with diet containing 0.1 mg·kg~-1 selenium as sodium selenium, designed as normal control; forty rats in group II were fed with diet containing 0.1 mg·kg~-1 selenium as sodium selenium, designed as model control; group III-V with forty rats each were fed with diet containing 0.3, 1.0, 3.0 mg·kg~-1 selenium as selenium-enriched malt respectively. To balance the nutrition content among each group, normal malt which was not treated with selenium was added into the diets of the relative groups. The nutrition contents except the selenium content of the diet in each group were similar and accord with the standard of NCR.Drinking water with 100 mg·L~-1 diethylnitrosamine (DEN) were given to rats in group II -V for sixteen weeks to induce the heptocarinoma, after then normal water was given in another two more weeks. During the course of hepatocarcinogenesis, body weight, histopathological changes of liver, and alanine amiotransterase (ALT), alkaline phosphatase (ALP) and albumin (ALB) in plasma were observed. At the end of the eighteenth week, all the remainder rats were killed humanely and the number of hepatoma nodules, body weight, liver weight, relative liver weight and hepatoma incidence were recorded. The results indicated that histopathological changes of liver, the number ot hepatoma nodules, relative liver weight, hepatoma incidence and activities of plasma ALT, ALP activies in the groups of selenium-enriched malt were lower or significantly lower than those in the model group, while plasma ALB was higher or significantly higher than those in the model group, and the relationship of dosage-effect were also showed with certain extent in this experiment. The result demonstrated that selenium-enriched malt could attenuate the lesion of liver cells induced by DEN and postpone the progress of hepatocarcinogenesis in rats.Test 2 Effect of selenium-enriched malt on Proliferating cell nuclear antigen in the hepatoma induced by diethylnitrosamine in rats. The aim of this experiment was to observe the effect of selenium-enriched malt on Proliferating cell nuclear antigen (PCNA) in the hepatoma induced by diethylnitrosamine in rats. The treatments to the rats were same as the experiment I. At the end of forth, eighth, twelveth, sixteenth and eighteenth week, five rats of each group were selected randomly and killed humanecly, and the expression of PCNA of liver was examined by immunohistochemistry. The number of the positive PCNA cells was counted, and then the PCNA index (PI) at the end of eighteenth week was also caculated. The results indicated that the number of PCNA positive cells in high content selenium-enriched malt groups were significantly lower than th...
|
PDF Full Text Request