EFFECTS OF MODERATE DIETARY RESTRICTION AND AGE ON BLOOD PARAMETERS AND METABOLIC ENZYMES IN LOBUND-WISTAR RATS

The effects of moderate dietary restriction (DR) on certain blood parameters and metabolic enzymes were studied in 80 male Lobund-Wistar rats at 6, 12, 18, 24 and 30 months of age. Two groups of rats were fed ad libitum (AL) or restricted (DR) to 12 g per day from weaning. Adult DR rats received 30% less diet per day when compared to adult rats in AL group. Blood glycohemoglobin and serum protein levels were significantly decreased by DR at 30 months of age. Blood glycohemoglobin levels increased significantly with age in AL rats, but not in those of the DR group. Hematocrit showed a significant decrease at 24 and 30 months in both groups. Serum glucose levels in rats were not affected by either diet or age. Five enzymes in the liver cytosolic fractions were determined. Activities of pyruvate kinase (PK) and lactate dehydrogenase (LDH) were significantly lower in the DR group than in the AL group at each age. Activities of glutamate-pyruvate transaminase (GPT), glutamate-oxaloacetate transaminase (GOT) and malate dehydrogenase (MDH) were significantly higher in the DR group than in the AL group. The results suggest that moderate DR decreased the glycolytic pathway and appears to stimulate amino acid metabolism and increase gluconeogensis.