Effect of a polyunsaturated fatty acid-rich diet on macrophage and lymphocyte metabolism of diabetic rats.

Diabetic subjects present high susceptibility to infections but the mechanisms involved are not fully known. Macrophages and lymphocytes utilize glucose and glutamine at high rates and these metabolites are important for the function of these cells. The present study examines the activities of key metabolic enzymes in macrophages and lymphocytes obtained from alloxan-diabetic Wistar rats (10 weeks old, 7 rats each group). Since the enteral diet was enriched with omega-6 polyunsaturated fatty acids (PUFA), the effect of these fatty acids was also investigated in the same animals. Diabetes caused a marked decrease of hexokinase activity (48%; 274.23 +/- 18.43 vs 143.29 +/- 10.35 units for control vs diabetic rats) in macrophages and of citrate synthase and glucose-6-phosphate dehydrogenase activities (70%; 321.76 +/- 9.18 vs 96.25 +/- 5.43 units for citrate synthase and 89.43 +/- 2.33 vs 23.13 +/- 1.09 units for G6PDh for control vs diabetic rats) in mesenteric lymph node lymphocytes. A PUFA-rich diet given for 6 weeks enhanced hexokinase activities by 30% (274.23 +/- 18.43 vs 342.48 +/- 15.39, balanced vs PUFA-rich diets for normal and 143.29 +/- 10.35 vs 189.67 +/- 9.57 for diabetic rats) and reduced citrate synthase activities by 43% (30.31 +/- 1.73 vs 17.42 +/- 0.95, balanced vs PUFA-rich diets for normal and 29.34 +/- 1.23 vs 16.73 +/- 1.02 for diabetic rats) in macrophages, and reduced (< 50%; 59.67 +/- 3.45 vs 48.87 +/- 3.37 for hexokinase and 321.76 +/- 2.33 vs 161.66 +/- 9.97 for citrate synthase, balanced vs PUFA-rich diets) the activities of both enzymes in lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)