Figure 1.

Histomorphometric analysis of recovering small intestine after 3 h of ischemic injury demonstrates that early epithelial regeneration begins 2 DPI. A: immediately after injury, there is significant surface epithelial loss and contraction of villi to their base (0 DPI). By 1 DPI, the villi are absent and there is loss of crypt epithelial cells. By 2 DPI, the crypts are lined by plump, cuboidal epithelial cells with prominent mitoses. Epithelial differentiation is seen by 3 DPI with tall columnar cells lining crypts, basal polarity, and evidence of crypt elongation. Scale bar inset 20 µm. Scale bar panel 100 µm. B: stack graph defining the histological categories of epithelial recovery and demonstrating that early regeneration occurs at 2 DPI; n = 3–6 pigs. DPI, days postinjury.