Effects of maternal feeding with different high fat diets on cellular composition of lymphoid compartments in the spleen and lymphoid infiltrates of mammary gland tumors in rat offspring

We studied whether feeding pregnant female rats a 15% olive-oil diet affects the splenic lymphoid system and synthesis of apoptosis-related proteins in offspring with chemically induced mammary glands tumors. Rat mothers were fed either a 7% corn-oil or a 15% olive-oil diet. Five-week-old offspring were exposed twice to the carcinogen, dimethylbenz(a)antracene, (10 mg/rat) and divided into 3 groups. Control group fed the 7% corn-oil control diet as their mothers. The first experimental group was fed a control diet (7% corn-oil) whereas their mothers were fed 15% olive-oil diet. The second experimental group was fed the same 15% olive-oil diet as their mothers. Results of experiments were studied 4 months later. The activity of lymphoid elements of the spleen and of tumors were studied using immunohistochemical methods for evaluating different types of lymphocytes (B and T cells) and the synthesis of apoptosis-related proteins (Fas ligand, p53, Bcl-2). Maternal feeding a diet rich in olive oil before and throughout pregnancy resulted in different manners in their offspring, and results were dependent on diets fed their progeny. In the spleen, feeding mothers the 15% olive-oil diet inhibited the reaction of zones producing the B and T lymphocytes in offspring fed a control diet. In offspring fed the 15% olive-oil diet, the activation of the lymphoid system was seen. In tumors, activity of T cell killers/suppressors, macrophages and of the synthesis of Bcl-2 protein was found to manifest on their border. The positive correlation was found between the most parameters studied. The effect of maternal feeding a high-fat diet was manifested in a different manner in different parts of the spleen. In the white pulp, the effect was manifested only in an increase in the size of the germinal center due to the activation of production of B cells and was seen even in offspring fed a regular diet. In the red pulp, such effect was exhibited in an increase in the number of T cell killers and macrophages in both groups of progeny. The findings indicate that feeding mothers a diet high in olive oil concentrations retains its cancer-modulating role in offspring, but such a role is manifested in different manners, mostly at a cellular level.