HYPERADRENOCORTICISM, ATTENUATED INFLAMMATION, AND THE LIFE-PROLONGING ACTION OF FOOD RESTRICTION IN MICE

Food restriction (FR), which extends life span, is associated with an enhanced diurnal elevation of glucocorticoids. This increase in glucoc orticoids may contribute to longevity by chronically enhancing the sam e protective mechanisms mobilized during acute stress. The objective o f this study was to determine if attenuation of inflammation, a presum ably protective effect of glucocorticoids, occurs in FR mice. Two-mont h-old male BALB/c mice ware either fed ad lib (AL) or FR (60% AL calor ies) for 2 months. After one month, the diurnal elevation of plasma co rticosterone was threefold higher in FR mice. Two weeks after corticos terone sampling, a hindfoot pad of each mouse was injected with 20 mu l of 4% carrageenan. Maximum observed edema did not differ between FR and AL groups, but edema was reduced at onset and fell earlier in FR m ice. Results indicate that at least one inflammatory reaction is atten uated by FR and are consistent with the hypothesis that FR enhances a potentially protective glucocorticoid activity.