4, 8, and 12 weeks of dietary treatment, and after exercise training by the 16th
week. After an overnight fast, unanesthetized rats were injected intraperitoneally
(ip) with 50% glucose solution, 1.5 g/kg body weight (BW). Blood samples were
obtained from the tail vein before and at 30, 60, 90, and 120 min after glucose
injection. Insulin tolerance tests (ITTs) were performed after the acclimatization
period and at 8 and 12 weeks of dietary treatment. After an overnight fast,
unanesthetized rats were injected ip with Novolin R human insulin
(Novo Nordisk, Brazil), 0.75 U/kg BW. Blood samples were obtained from the tail vein
before and at 15, 30, 60, and 90 min after the insulin challenge. Blood glucose
concentrations were measured with an Accu-Check glucose meter (Roche Diagnostic,
USA).