Figure 3.

Immunofluorescent staining for zonula occludens (ZO)-1 (green) and claudin-3 (red) after various periods of cold storage (CS); strong immunofluorescent signal for both proteins after 8 h CS in rat (A), pig (B), and human intestine (C); after 14 h, ZO-1 signal was lost in rat (D) but not pig (E) or human (F) intestinal mucosa; after 24 h (J–L) of CS, ZO-1 staining was absent and claudin-3 revealed diffuse membrane staining and cytoplasmic staining in rat intestines (G), while in pig (H) and human (I) intestines, ZO-1 signal was maintained and claudin-3 stained more diffuse, stronger on the subjunctional basolateral membrane, together with some cytoplasmic staining. Nuclei were stained blue using 4′,6-diamidino-2-phenylindole (DAPI). Images were acquired from areas where enterocytes still remained attached to the lamina propria and as close to the villus tip as possible. Original magnification ×400, scale bar, 10 μm.