INHIBITION OF FEEDING BY A NITRIC-OXIDE SYNTHASE INHIBITOR - EFFECTS OF AGING

Nitric oxide has been demonstrated to play a role in the modulation of food intake. With advancing age, there is a physiological decrease in food intake. The effect of the nitric oxide (NO) synthase inhibitor, N-G-nitro-L-arginine methyl ester (L-NAME) on food intake in C57BL/6Nn ia mice aged 3, 12 and 24 months was studied. L-NAME was more effectiv e at decreasing food intake in 12- and 24-month-old mice than in the 3 -month-old mice. NO synthase levels in the hypothalamus were increased in 16- and 25-month-old mice compared to 6-month-old mice (P < 0.01). NO synthase mRNA increased in 16- compared to 6-month-old mice, but d ecreased in 25-month-old mice. Overall, these studies may suggest that nitric oxide may play an increasingly important role in the feeding d rive with advancing age.