There is now substantial evidence for the involvement of inflammation in the pathogenesis of the decreased GFR associated with acute renal ischemic injury. In this regard, there is experimental evidence that iNOS may contribute to tubular injury during ARF. Hypoxia in isolated proximal tubules has been shown to increase NO release (54), and Western blot analysis in ischemic kidney homogenates has demonstrated increased iNOS protein expression (55). An antisense oligonucleotide was shown to block the upregulation of iNOS and afford functional protection against acute renal ischemia (55). Moreover, when isolated proximal tubules from iNOS, eNOS, and neuronal NO synthase (nNOS) knockout mice were exposed to hypoxia, only the tubules from the iNOS knockout mice were protected against hypoxia, as assessed by LDH release (56). The iNOS knockout mice were also shown to have lower mortality during ischemia/reperfusion than wild-type mice (57).