Change in vessel ID in control and diabetic animals during infusion of vasoactive compounds, categorised by branching order and vessel size class. ACh (A &F; 3.0 μg/kg/min), SNP (B &G; 3.0 μg/kg/min), combined (C &H); L-NAME (10 mg/kg iv. bolus) + meclofenamate (2 mg/kg iv. bolus), combined + ACh (D &I) and combined + fasudil (E &J; 10 mg/kg iv.). Fasudil treatment resulted in a marked increase in diabetic second order vessel ID and the 40-100 μm small artery-arterioles compared to controls. Control, n = 6 and diabetic, n = 8. Values expressed as mean ± SEM. †P < 0.05 vs. control.