Immune components of the intestinal mucosae of ageing and protein deficient mice.

The studies were designed to investigate the effect of ageing and low protein (4%) diet on antibody-dependent cell-mediated cytotoxicity (ADCC) and IgA concentration in the intestine. Both ADCC activity and IgA concentration were shown to reach mature levels at 17 weeks old. The effect of ageing was greater on ADCC activity which showed a drastic drop in activity at 75 weeks old than IgA which had only a slight decline in concentration at this age. The low protein diet has a greater suppressive effect on IgA concentration than on ADCC activity. As the duration of feeding low protein to the young mice increased, greater decline in IgA concentration in the intestine was observed. There was, however, no significant difference from the normal mice in ADCC activity and IgA concentration of aged and adult mice given short term (8 weeks) low protein diet.