EXOGENOUS HYDROGEN SULFIDE (H2S) 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.