Impact of arginase II on CBF in experimental cortical impact injury in mice using MRI

Traumatic brain injury (TBI) results in reduced cerebral blood flow (CBF) and low levels of the vasodilator nitric oxide (NO) may be involved. Arginase II negatively regulates NO production through competition for the substrate L-arginine. We determined whether arginase II-deficient (ArgII(-/-)) mice would show improved CBF after TBI through arterial spin-labeling magnetic resonance imaging (MRI). The ArgII(-/-) mice exhibit a significantly improved CBF recovery after trauma in the perilesional brain (P=0.0015) and in various other brain regions. In conclusion, arginase II deficiency leads to a better CBF recovery after TBI and implicates arginase II in hemodynamic processes.