Age-related bias in function of natural killer T cells and granulocytes after stress: reciprocal association of XXXX hormones and sympathetic nerves.

@entity19 @entity1425 @entity3202 @entity2819 @entity134 @entity701 @entity2661 @entity99
Stress-associated immune responses were compared between young (8 weeks of age) and old (56 weeks) @entity19 . Since stress suppresses the conventional immune system (i.e. T and B cells) but inversely activates the primordial immune system (i.e. extrathymic T cells, NKT cells, and granulocytes), these parameters were analysed after restraint stress for 24 h. The thymus became @entity3202 as a function of age, and an age-related increase in the number of lymphocytes was seen in the liver. Although the number of lymphocytes in both the thymus and liver decreased as the result of stress, the magnitude was much more prominent in the thymus. To determine stress-resistant lymphocyte subsets, two-colour immunofluorescence tests were conducted in the liver and spleen. NKT cells were found to be such cells in the liver of young @entity19 . On the other hand, an infiltration of granulocytes due to stress was more prominent in the liver of old @entity19 than in young @entity19 . @entity99 as a result of stress was prominent in young @entity19 . This age-related bias in the function of NKT cells and granulocytes seemed to be associated with a difference in the responses of @entity2661 (high in old @entity19 ) and @entity2819 (high in young @entity19 ) after stress. Indeed, an injection of @entity1425 mainly induced the infiltration of granulocytes while that of @entity701 activated NKT cells. The present results suggest the existence of age-related bias in the function of NKT cells and granulocytes after stress and that such bias might be produced by different responses of sympathetic nerves and @entity134 hormones between young and old @entity19 .
