Effect of laser irradiation on cellular metabolism of salivary glands and glycaemic state of diabetic-induced streptozotocin rats

Author(s)

Alyne Simões

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia (FO/SDO)
• Defense date: 2008-06-03

Examining board members

Jose Nicolau; Maria Cristina Chavantes; Victor Elias Arana Chavez; Patricia Moreira de Freitas; Maria Teresa Botti Rodrigues dos Santos

• Advisor: Jose Nicolau

Abstract

Considering that experimental diabetes alters rat salivary gland morphology and function, the aim of this study was to evaluate the effect of laser irradiation (LI) on the glycaemic state and some biochemical parameters of the parotid glands (PG) and submandibulary glands (SMG) in diabetic and non diabetic rats, which were divided into 8 groups: D0/5/10/20 and C0/5/10/20, respectively. Diabetes was induced by administration of streptozotocin (60 mg/kg) and confirmed later by the glycaemia results. Twenty-nine (29) days after the induction, the PG and SMG of groups D-C5, D-C10 and D-C20, were irradiated with 5, 10 and 20 J/cm2 of laser diode (660nm/100mW) respectively. On the following day, the rats were euthanized and the blood glucose determined. The PG and SMG were removed and total protein concentration and amylase, peroxidase and catalase activities were performed, as well as, ionic and histological analysis. The analysis of the results (ANOVA and Tukey tests) revealed a decrease in the glycaemia level for groups D5 and D20 (p<0.05). In addition, diabetic rats showed higher catalase and peroxidase activities than non diabetic groups, without radiation. The doses of 5 and 20 J/cm2 decreased catalase activity, of PG and SMG, of diabetic groups to non diabetic values (p<0.05). Moreover, the dose of 10 J/cm2 also was effective to SMGs. Histological analysis showed accumulation of lipids droplets on parotid glands of diabetic animals. However, the lipid droplets quantity was lower in comparison with that observed to non irradiated diabetic animals. The results of the present study suggest that the classical organs which control glycaemia should also be analyzed after being irradiated with LI, once hyperglycaemia and alterations of the antioxidant system are the main causes of diabetes complications. (AU)

• FAPESP's process: 05/04506-0 - Effect of low intensity laser therapy on submandibular and parotid glands cell metabolism in streptozotocin-induced diabetic rats
• Grantee: Alyne Simões Gonçalves
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)