BACKGROUND: The colonic response to obstruction is poorly understood. The aim of this study was to investigate the colonic morphology and the variation of collagen and protein content during the development of a left-sided colonic obstruction. METHOD: 36 Wistar rats underwent a ligature obstruction of the left colon. Groups of 6 animals were killed immediately (0h; control group) or after 6, 12, 24, 48 and 72hs after the obstruction. The length and weight of the colon were registered as well as the colonic diameter in four segments: at 1cm above and below the ligature, at the splenic flexure and at the ceccum. Biopsies of these sites, containing all layers of the colon, were assayed for hydroxyproline and protein concentration. RESULTS: The colonic length decreased from 6 to 24hs after obstruction, returning to normal values after 48hs. Proximally to the ligature, a significant increase of the diameter was observed at 1cm above the ligature after 6hs, at the splenic flexure, after 12hs, and at the ceccum, 24hs later. Colonic weight was higher after 48hs (4,6 ± 0,5g vs. 3,4 ± 1,1g; p < 0,05). Below the ligature there was no variation in the weight of the specimens, neither in the hydroxyproline nor in the protein concentrations. Above the ligature however, the specimens became significantly heavier after 6hs and higher in hydroxyproline centent after 24hs. Protein content diminished in all proximal sites. CONCLUSIONS: The obstructed colon initially contracts and then progressively enlarges, dilates, and becomes heavier. After obstruction, colonic protein concentration progressively diminishes, although the hydroxyproline content transitorily increases.
Intestinal obstruction; Collagen; Colon
