Long-term Exposure of Variable Dietary Protein-to-Carbohydrate Ratio: Effect on Brain Regional Glutamatergic Activity with Age

摘要

Glutamatergic activity of hypothalamus and hippocampus of young (3 months) male albino rats having normal diet [protein (20%)–carbohydrate (68%)] was increased with the increase of age. Long-term (60 consecutive days) feeding of low protein (8%)–high carbohydrate (80%) diet (LP–HC) increased glutamatergic activity in these brain regions of young rats and decreased that in aged (18 months). On the contrary, supplementation of high protein (50%)–low carbohydrate (38%) diet (HP–LC) under similar condition decreased glutamatergic activity in those brain regions of young and increased that in aged brain regions. Thus, prolonged exposure of LP–HC diet may damage young brain; whereas, HP–LC diet under similar condition causes excitotoxicity to aged brain. Therefore, considering the present scenario in relation to metabolism and receptor activity of glutamatergic system, it may be suggested that long-term consumption of LP–HC and HP–LC diets modulate the brain regional glutamatergic activity reversibly with age.