THE EFFECT OF ASCORBIC ACID ON PATHOHISTOLOGICAL TUMOR CHARACTERISTICS AND PHENOTYPE CHARACTERISTICS OF LYMPHOCYTES DURING THE DEVELOPMENT OF EXPERIMENTAL MAMMARY CARCINOMA IN MICE
TIn our previous study we demonstrated that high doses of
ascorbic acid prolonged the survival of mice with experimental mammary
carcinoma. In this work we studied, ussing the same model, pathohistological
characteristics of the tumor and phenotypic changes of lymphocyte subsets in the
spleen. Experiments were performed on CBA/H mice. The growh of experimental
tumor was induced by injection of mammary adenocarcinoma cells intramuscularly
at the femoral region of mice. The animals were divided into control group and
three experimental groups (I, II and III). Mice from experimental groups were
treated peroraly with 10, 100 and 1000 mg/kg body mass (b.m.) of
ascorbic acid, respectively, whereas control mice received physiological saline.
Mice were sacrified after 7, 14 and 21 days from the beginning of the
experiment. Total tumor mass and its pathohistological characteristics, spleen
mass and cellularity as well as relative and total numbers of T cells, B cells
and T cell subsets (CD4+ and CD8+) in the spleen, were analyzed. High doses of
ascorbic acid decreased tumor mass, stimulated proliferation of fibroblasts and
formation of capsula arround the tumor, induced tumor necrosis and increased the
number of tumor infiltrating lymphocytes. Changes of lymphocyte subsets and
their numbers varied depending on the applied dose of ascorbic acid and the time
elapsed following tumor induction. The most prominent changes, manifested by an
increase in the number of CD4+ T cells were observed on the 14th day in II
experimental group. Our results suggest that the beneficial effect of ascorbic
acid on experimental tumorogenesis in our model was the consequence of its
influence on the tumor and on the immune system. Acta Medica Medianae 2005;
44(2): 23-31.
Key words: mammary adenocarcinoma, mouse, ascorbic acid, histopathology, lymphocytes, phenotype