EXOGENOUS HYDROGEN SULFIDE (H 2 S) IMPROVES THE ENDOTHELIAL AND RENAL EXCRETORY FUNCTIONS IN STREPTOZOTOCIN INDUCED WKY DIABETIC RATS

Nephropathy is one of the most common microvascular complications of diabetes. Hydrogen sulfide (H2S) has been implicated in controlling the renal glomerular (vascular) and tubular functions. This study investigates the metabolism of H2S and its effect on the progression of diabetic nephropathy. Diabetes was induced in WKY rats by streptozotocin in two groups. One diabetic group received NaHS, a H2S donor. While a vehicle treated group served as a control. Blood pressure was measured in conscious rats and at the end of the treatment period in anesthetized rats. In addition, pulse wave velocity (PWV) was also observed. Plasma and urine H2S levels and creatinine concentration and electrolytes were measured weekly throughout the 34-day period. Diabetic rats had lower (p<0.05) plasma and urine levels of H2S and lower urinary sodium to potassium ratio. Moreover, diabetic group had higher plasma sodium, higher absolute urinary sodium excretion, higher plasma creatinine and higher PWV (all p<0.05) but with similar mean arterial pressure compared to control (p>0.05). Treatment with the H2S donor restored H2S, plasma creatinine, plasma sodium and urinary sodium to potassium ratio significantly in diabetic-NaHS treated group and also reduced the PWV (all p<0.05). Moreover, the treated diabetic group had higher (p<0.05) creatinine clearance compared to diabetic group. The results suggested that exogenously administered H2S improves the renal excretory functions and vascular endothelium impairment in experimental diabetes in rats.