Abstract
The effect of malnutrition-induced during the suckling period-and the subsequent feeding of stock diet on the mesenteric lymph nodes (MLN) of growing rats was studied. Rats of the Wistar strain were suckled in groups of 14–16 per dam since birth to weaning (23 days) to obtain undernutrition according to the standard procedure of McCance and Widdowson. A group was sacrificed at weaning (Uo) and the remaining animals fed stock diet ad libitum were killed at 36, 45 and 65 days of age; well-nourished age-matched animals were used as controls. Body weight (bw) was determined and mesenteric lymph nodes were removed; its weight, cell number (Nc) and the B cell surface antigen determinant (αs+) was characterized. Body weight, total number of cells and the absolute number of cells s+ were significantly diminished at weaning (p < 0.001). MLN weight when expressed as mg/bw0.75 was significantly higher in the experimental groups (U) when compared to the controls of the same age (p < 0.01), indicating hypertrophy of this lymphoid organ. The absolute number of cells s+ from undernourished rats never reached control values even at 65 days of age (p < 0.001).
These results suggest that undernutrition induced during and limited to the suckling period produces important damages to GALT, expressed as a hypertrophy of the MLN accompanied by a significant loss of IgA B cells.