The effect of various dietary restricted regimes on some immunological parameters of mice.

To test the effect of dietary protein restriction on mitogenesis and the mixed leukocyte reaction in the mouse immune system two protocols were followed: 1) a 4% protein diet ad libitum and 2) a standard diet of 24% protein fed only on alternate days, Monday, Wednesday, and Friday (intermittent feeding). The effect of dietary restriction was tested on weanling animals, placed on the dietary regimes for 1 and 6 month periods and adult animals (17 months of age) for 6 months of restriction. The results indicate that dietary restriction has a profoundly suppressive effect on mitogenesis and MLC1 during the first months of growth (i.e. weanling animals tested after 1 month of restriction). After 6 months of continued restriction suppression was no longer observed in the weanling animals. The 17 month old animals placed on restricted dietary regimes for 6 months showed results similar to the control group. The intermittently fed animals present a more complex picture. Initial suppression of the responses, observed in weanling animals after 1 month of restriction gave way to responses which are significantly higher than control levels after 6 months of dietary restriction. The results are discussed in terms of a general model of immunological stress.