Low Protein Diet Consumption Antagonize the Age-associated Change in Hypothalamic GABA Receptor activity

Activation or inhibition of hypothalamic GABAergic activity and immunopotentiation or immunosuppression during aging depends on the variation of the amount of dietary protein as well as the duration of its supplementation. Here we evaluate the effect of low (5%) and high (40%) protein diet on the functional state of hypothalamic GABA receptor in the aging brain in albino rats. Consumption of low protein diet (LPD) retards the loss of hypothalamic GABA receptor sensitivity in both the low and high affinity sites with an increase in density of high affinity GABA receptor. Supplementation of for 30 consecutive days retarded the age-associated (3 to 18 months) Consumption of the same protein diet for 7 consecutive days reflects less effect than that observed under long-term period. High (40%) protein diet (HPD), on the other hand, under LT period potentates the age-induced loss of both high (from (63% 71%) and low (40% 60%) affinity hypothalamic GABA receptor sensitivity, without any significant change in ageassociated increase in high affinity hypothalamic GABA receptor density. These results thus suggest that the age-induced changes in hypothalamic GABA receptor sensitivity and density may be (i) antagonized by long-term supplementation of LPD by restoring the age-associated loss of sensitivity of both low and high affinity and increase in density of only high affinity hypothalamic GABA receptor and (ii) augmented by long-term intake of HPD by potentiating only the age-associated loss of sensitivity of hypothalamic GABA receptor of both the affinity sites.