Nutrition Research, Vol. 20, No. 4, 527-535.2000 pp. Copyright 0 2000 Else&r Science Inc. Printed in the USA. All nghts reserved 027 1-53 17/00/.&e front matter ELSEVIER zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA PII: s0271-s317(00)00144-s PROTEIN MALNUTRITION DOES NOT IMPAIR GLUCOSE METABOLISM ADAPTATIONS TO EXERCISE-TRAINING Rozinaldo Galdino MS, Carla Cassia de Souza Almeida Departamento de EducacZo Fisica e Motricidade Humana, UFSCar, Sao Carlos, SP, Brazil Eliete Luciano PhD and Maria Alice Rostom de Mello’ PhD Departamento de Educacao Fisica, IB, UNESP, Rio Claro, SP, Brazil ABSTRACT Malnutrition is a common health problem in developing countries and is associated with alterations in glucose metabolism. In the present study we examine the effects of chronic aerobic exercise on some aspects of glucose metabolism in protein-deficient rats. Two groups of adult rats (90 days old) were used: Normal protein group (17%P)- kept on a normal protein diet during intra-uterine and post- natal life and Low protein group (6%P)- kept on a low protein diet during intra- uterine and post natal life. After weaning (21 days old), half of the 17%P and 6%P rats were assigned to a Sedentary (Sed) or an Exercise-trained (Exert = swimming,1 hrfday, 5 days/week, supporting an overload of 5% of body weight) subgroup. The area under blood glucose concentration curve (AG) after an oral glucose load was higher in 17%P Sed rats (20%) than in other rats and lower in 6%P Exert (11%) in relation to 6% Sed rats. The post-glucose increase in blood insulin (AI) was also higher in 17%P Sed (9%) than in other rats. On the other hand, the glucose disappearance rate after exogenous subcutaneous insulin administration (Kitt) was lower in 17%P Sed rats (66%) than in other rats. Glucose uptake by soleus muscle was higher in Exert rats (30%) than in Sed rats. Soleus muscle glycogen synthesis was reduced in 6%P Sed rats (4 1%) compared to 17%P Sed rats but was restored in 6%P Exert rats. Glycogen concentration was elevated in Exert (32%) rats in comparison to Sed rats. The present results indicate that glucose-induced insulin release is reduced in rats fed low protein diet. This defect is counteracted by an increase in the sensitivity of the target tissues to insulin and glucose homeostasis is maintained. This adaptation allows protein deficient rats to preserve the ability to appropriately adapt to aerobic physical exercise training. 0 2000 Elsevla Sc,ence 1°C KEY WORDS: Protein malnutrition, Exercise training, Glucose metabolism, Insulin, Skeletal muscle. ’ Address correspondence to: Maria Alice Rostom de Mello, Departamento de Educacao Fisica, IB, UNESP, 13506-900, Rio Claro, SP, Brazil, Tel.: 19-5264165; Telefax: 019- 5340009. 527