L-theaninin diyabetik sıçanlarda böbrek dokusu üzerine etkilerinin incelenmesi

Diabetes mellitus (DM) is a common disease in the world, characterized by hyperglycemia that may result in damaging and dysfunctioning of kidney. The aim of this study was to determine whether L-Theanine (LTEA), an amino acid specific to green and black teas, which are widely consumed in the world, could be protective against damage in the kidney tissues of diabetic rats. All rats were separated into four groups (n=6/group): SHAM, LTEA, DM, and DM+LTEA. DM was induced by i.p. injections of 120 mg/kg nicotinamide (NA) and 60 mg/kg streptozotocin (STZ). LTEA treatment was administered intragastrically for 28 days. Serum levels of glucose, creatinine, blood urea nitrogen (BUN), albumin, and electrolytes were determined by an autoanalyzer. Serum and tissue cystatin C and angiotensin-converting enzyme 2 (ACE2) levels were determined by using ELISA kits, and oxidized and total reduced glutathione (GSSG and TGSH respectively) levels by using commercial assay kits. Kidney tissues were also evaluated histopathologically. LTEA treatment in diabetic rats decreased serum GSSG/TGSH ratio and iron levels, and increased renal TGSH levels, significantly (p<0.05). On the other hand, although this treatment decreased serum cystatin C levels insignificantly, it could not be effective in changing kidney cystatin C and serum/kidney ACE2 levels (p>0.05). Nevertheless, it was effective in reducing the histopathological complications seen in diabetic rat kidneys. In conclusion, it is possible to say that LTEA is an amino acid that may contribute to reducing complications related to diabetic nephropathy in rats. Nonetheless, the effectiveness of LTEA against damage to the diabetic human kidney needs to be investigated. Keywords: Angiotensin-Converting Enzyme 2, Cystatin C, Diabetes Mellitus, Electrolyte, Glutathione, Kidney, L-Theanine