Figure 7. Magnitude of intestinal arteriolar response. A1, inflow first-order arteriole; pA3, proximal third-order arteriole; dA3, distal third-order arteriole; Max, maximum dilation response to SNP. At 2 hours after resuscitation, PR (first bar of each pair) produced a significant vasodilation at all arterioles examined. The magnitude of this dilation was significantly less than the ACh-mediated dilation (second bar of each pair). *P < .001 by two-way ANOVA and Bonferroni posttest.