Figure 6.

N2 peptide blocks vascular leak in intestinal RI. (A, i–iii) Representative images of microvilli within the jejuneum of sham, saline, or N2 administered mice, respectively. Mice were treated for RI as described in Fig. 5, except that 5 min before reperfusion the later two groups were injected i.v. with a mixture of vascular probe (AngioSense 680, red) and Rhodamine 6G (green) in saline or N2 peptide (40 μM final concentration). (i) Results of the sham group identify microvasculature of individual microvilli in which red indicates blood vessels and green outlines enterocytes and lamina propria. (ii) Saline group images indicate extensive leakage of the vascular probe into lamina propria and surrounding tissues. (iii) N2 peptide group results indicate relatively normal vasculature within microvilli and limited leakage of vascular probe. (B) Scatter plot of ratio of intensity of signal of vessels (V) versus background (B). The horizontal lines indicate the mean of samples analyzed. Each symbol indicates a representative measurement from representative images of at least three mice per group, and means ± SD were calculated. *, P < 0.001, as determined by Student's t test.