Pancreatic lesions can produce metabolic disorders. Light-emitting diode (LED) has been used as a safe and effective phototherapy for cell proliferation and regeneration. We investigate the effects of phototherapy using LED irradiation on the pancreas after the injection of streptozotocin (STZ) to induce experimental diabetes and evaluate that the β cells can regenerate in the pancreas in an in vivo model and observe its implications on the control of carbohydrate metabolism. Twenty Wistar rats were randomized into three groups: non-diabetic control, diabetic control, and diabetic treated with LED. Except for the non-diabetic control group, all were induced to diabetes type I by streptozotocin injection. Treated groups were irradiated by LED: λ = 805 nm; 40 mW, 22 s; spot diameter 5 mm, spot area 0.196 cm2, 0.88 J that it was applied on pancreas projection area for 5 consecutive days and monitored for 30 days. Diabetic group treated with LED showed regeneration of islets and ducts (p = 0.001) on the pancreas. Intraperitoneal insulin tolerance test showed differences between the diabetic control and diabetic treated groups (p = 0.03). In diabetic control group, the hepatic glycogen content was 296% lower when compared with diabetic treated with LED. Furthermore, in the diabetic control group, the glycogen content of the gastrocnemius muscle was 706% smaller when compared with diabetic treated with LED. This study shows that LED was able to modify morphological and metabolic features and also altered carbohydrate metabolism on irradiated pancreas in experimental model of diabetes.
Keywords: Diabetes; Glycogen; Islets of Langerhans; Light-emitting diode; Pancreatic ducts; Phototherapy.