Radially Induced Enterogenesis: A Unique And Simple Bowel Stretching With PEG In Mouse

Introduction: Recent studies have demonstrated thatthe small intestine can grow by applying mechanical forces to the bowel wall, with over a 2.7-fold increase in bowel length over 10 days in a pig model. However, the mechanisms which account for this growth is unknown, and would be best examined using a mouse model. The purpose of this study is to establish the feasibility of developing a distractive-induced small bowel growth model in mice. Methods: 12-week old C57BL/6J mice had a 2.5-3.0 cm jejunal segment taken out of continuity, and distended with 300-400 ml of polyethylene glycol (PEG: 3350 KDa allowing for continued entry of water with secondary development of radial and linear distractive forces PEG group), or without stretching (control group). Segment length and diameter were measured intra-operatively and after 5 days. Villus height, crypt depth, muscle thickness in the isolated segment were assessed. The rate of epithelial cell proliferation (5-bromo-2-deoxyuridine: BrdU incorporation) was also examined and compared to controls. Results: Separated segments showed no signs of intestinal ischemia at harvest. After 5 days, PEG segments showed significant increase in length and diameter compared to isolated controls (Table). Villus height, and muscular layer thickness increased in stretched groups and most significantly crypt depth was significantly increased. The PEG group also showed significantly increased rate of epithelial cell proliferation in crypts vs. controls. Conclusions: Radial distraction-induced enterogenesis with PEG is a viable method for increasing small intestinal length and diameter without compromising intestinal function. This phenomenon may provide a new method for studying mechanisms leading to intestinal growth with the application of distractive forces. Tabled 1 Groups Lengthening rate (%) Dilated rate (%) Villus height(μm) Crypt depth (μm) Muscle thickness(μm) BrdU positive cells/crypt Isolated control 2.36±4.04 9.19±7.45 296.00±19.72 79.05±6.64 51.72±4.01 0.95±0.17 PEG Segments 17.92±9.85∗ 74.33±12.69 ∗ 308.80±18.10 120.50±15.77∗ 59.64±12.77 2.90±0.33∗ Percentages of lengthening, dilatation; villus, crypt and muscle morphology and BrdU positive cells/crypt are shown. Data are expressed as mean±SD. ∗P<0.05; comparing isolated control vs. stretched groups using unpaired t-test. Open table in a new tab Percentages of lengthening, dilatation; villus, crypt and muscle morphology and BrdU positive cells/crypt are shown. Data are expressed as mean±SD. ∗P<0.05; comparing isolated control vs. stretched groups using unpaired t-test.