Taurine can enhance the protective actions of metformin against diabetes-induced alterations adversely affecting renal function.

Abstract

AbstractThe present study was designed to examine the role of taurine (TAU) on the actions of the oral hypoglycemic drug metformin (MET) against diabetes-induced metabolic and oxidative changes influencing renal function. The experiments were carried out with male Sprague-Dawley rats, 225–250 g, assigned to groups of 6. Diabetes was induced with streptozotocin, 60 mg/kg i.p, in 10 mM citrate buffer pH 4.5. After 14 days, separate groups of diabetic rats received MET, 2.4 mM/kg/day p.o., TAU, 2.4 mM/kg/day p.o., MET plus TAU, or insulin (INS), 4 U/kg/day s.c.. The treatments were daily, starting from day 15, and continued for an additional 41 days. Normal rats and untreated diabetic rats served as controls. The animals had free access to a standard rat chow and tap water throughout the study. A 24 h urine sample was collected starting on day 56. Blood and kidney samples were collected on day 57 and used to isolate plasma and prepare kidney homogenates, respectively, for biochemical testing. Diabetic rats were hyperglycemic, hypoinsulinemic and dyslipidemic, showed proteinuria, hypernatremia, hyperkalemia, and plasma and renal oxidative stress, and, relative to normal rats, exhibited higher levels of blood HbA1c and of plasma TGF-β1, creatinine and urea nitrogen. All the treatments were found highly protective against these changes, with INS appearing more potent than MET, TAU or MET-TAU except for the intracellular redox status. MET was more effective than TAU in reducing glucose-related metabolic changes and proteinuria, less in controlling hypertriglyceridemia and in preserving antioxidant enzymes, and about equipotent against the other changes. Supplementing MET with TAU enhanced the actions of MET to different extents. Overall, this study finds that MET and TAU can offer the same pattern of protection as INS against diabetes-related metabolic and biochemical changes relevant to renal function, and that TAU can enhance the protective actions of MET on diabetes–related renal biochemical and functional alterations.KeywordsDiabetic NephropathyMesangial CellDiabetic Kidney DiseaseAdvanced Oxidation Protein ProductPlasma Urea NitrogenThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.