EFFECTS OF PHOTOBIOMODULATION ON RENAL FUNCTION IN RATS WITH DIABETIC KIDNEY DISEASE

Diabetic kidney disease (DKD) is one of the most serious microangiopathic complications of diabetes mellitus (DM). Evidences suggest that hemodynamic changes and cellular metabolism are related to the pathogenesis of chronic kidney disease (CKD), including mitochondrial dysfunction, oxidative stress, inflammation and dysregulation of the intestinal microbiotal.1,2 Photobiomodulation therapy (PBM) is a non-pharmacological therapy that uses red and infrared spectral range light, with a wavelength of 450 to 1100nm, to trigger photochemical changes within extracellular and intracellular structures, without heat release or with negligible thermal release.3,4 Pre-clinical and clinical studies in a rat model of CKD induced by metabolic syndrome showed a reduced blood pressure, increased glomerular filtration rate and decreased tubulointerstitial fibrosis.2 after the photobiomodulation. Objective: Evaluate the effects of photobiomodulation on renal function, oxidative profile, renal hemodynamics in rats with DKD. 

Adult male Wistar rats, weighing 280-300 g were applied and categorized as follows: Citrate (CT): animals receiving streptozotocin vehicle (citrate; i.v., caudal, single dose, 1st day of experimental protocol); Diabetes Mellitus (DM): animals that received streptozotocin (STZ, 60 mg/kg; i.v.; single dose, 1st day of experimental protocol, followed up to the 45 day); Diabetes Mellitus + Low intensity laser (DM+L): DM animals that, on the third day of the protocol, were irradiated with a low intensity infrared laser (808nm wavelength, output power of 100mW, energy density= 3 J/cm2, on the right and the left flanks; 3 times a week 6 weeks). The protocol lasted 45 days. Renal function (serum creatinine-SCr; clearance- creatinine-Clcr; inulin clearance-Clin), oxidative profile (urinary peroxides; TBARs).

The DM group showed a reduction in renal function evaluated by SCr, Clcr and CLin, while the DM+L group showed an attenuation the deterioration of renal function and when evaluating renal function and the oxidative profile (FOX, TBARs). 

The results reveal that PBM attenuates the reduction in renal function by interfering in the oxidative profile induced by DKD. Thus, PBM confirmed a relevant renoprotective effect in diabetic kidney disease.