Translocated bacteria in bowel wall specimens of pigs exposed to IAH for 24 h. Histological specimens (Gram-stained) of bowel walls of pigs exposed to an IAP of 15 mmHg (B) and 30 mmHg (A, C) for 24 h. Boxes in A1, B1, and C1 (magnification: each ×400) mark extracts which are magnified in A2, B2, and C2 (magnification: each ×1,000). Bowel wall layers are labeled 'M' (tunica mucosa), 'S' (tela submucosa), and 'Musc' (tunica muscularis). 'L': intestinal lumen, 'G': Gruenhagen's space (according to Park's classification , ischemic damage to the gut is accompanied by proportionally increasing lifting of epithelia. In this way, the developing space between the mucosa and submucosa is named after Gruenhagen). Histomorphological damage shown in A and B correlates to Park score 1 (B (IAP-15): subepithelial space at villous tips) and 2 (A (IAP-30): extended subepithelial spaces). Cocci as well as rods passed Gruenhagen's space (see arrows) and invaded the tela submucosa (A, B: translocation score 2 to 3). Bacteria shown in C even crossed the tela submucosa and started invading the tunica muscularis (see arrows).