Nitric Oxide Regulates Expression of Sonic Hedgehog and Hypoxia-Inducible Factor-1α in an Experimental Model of Kidney Ischemia-Reperfusion

This study was designed to determine the effect of L-arginine on hypoxia inducible factor alpha (HIF-1 α) and Sonic hedgehog (Shh) levels considered to be involved in the development of ischemia reperfusion (I R) injury. Unilaterally nephrectomized Sprague-Dawley rats were subjected to 60 minutes of left renal ischemia followed by 45 minutes of reperfusion. Group 1 were sham-operated animals; group 2, I-R Untreated animals; and group 3, I-R L-Arg-treated animals. Serum creatinine, blood urea nitrogen (BUN), and kidney malondialdehyde (MDA) levels were determined as well as examining the kidneys histologically. The treatment of rats with L-Arg produced a significant reduction in the levels of BUN, creatinine, MDA, and histopathological score compared to renal I R groups. The Shh expression in the tubulus epithelia were intensely increased in the I-R L-Arg group when compared to that of the Sham-control and the I-R untreated groups. Additionally, the HIF-1α expression in the tubulus epithelia and the interstitial spaces were intensely increased in the I-R L-Arg group. These findings suggest that NO reduces the renal dysfunction associated with I R of the kidney and may act as a trigger to induce Shh and HIF-1 activity.