Neurotensin reduces microbial translocation and improves intestinal mucosa integrity after abdominal radiation.

The effect of neurotensin (NTN) on preventing microbial translocation and preserving intestinal mucosal integrity after abdominal radiation was studied in rats. Animals were divided into the following groups: I (control), II (radiation control) and III (radiation and NTN). Radiation (1,100 cGy) was administered on the 1st day to groups II and III. NTN (300 micrograms/kg) was given intraperitoneally to group III animals, once daily for 3 days. On the 4th day, mesenteric lymph nodes (MLN) were obtained and cultured. Villi per centimeter (V/cm), villus height (Vh) and mitoses per crypt (M/c) were evaluated from ileal mucosa. Radiation increased positive MLN cultures, while treatment with NTN reduced them significantly. V/cm and Vh also returned to normal levels after NTN treatment, while M/c were increased in all irradiated animals. It was shown that NTN reduces bacterial translocation after abdominal radiation. Examination of ileal mucosa indicates that this can be attributed to the improvement of the mucosal integrity, due to the trophic effect of the hormone on the gut.

Effect of glutamine on intestinal mucosal integrity and bacterial translocation after abdominal radiation.

This study evaluates the effect of oral glutamine on intestinal mucosal integrity and bacterial translocation in rats. 80 animals were randomised into four groups: group 1 (chow diet and water), group 2 (chow diet and glutamine 3%), group 3 (radiation, chow diet and water), group 4 (radiation, chow diet and glutamine 3%). Groups 1 and 2 were fed for 5 days, then sacrificed. Groups 3 and 4 were fed for 12 days, irradiated on the 5th day and sacrificed on 1st, 3rd and 7th post-radiation days. Cultures from the mesenteric lymph nodes (MLN), portal vein (PV) and aorta (A) were taken and two tissue samples were also taken from the terminal ileum for light and electron microscopic examination. In non-radiated rats glutamine did not alter the histologic parameters of villous height (VH), mitoses per crypt (M/C) and muscle thickness (MT). Group 3 rats had severe mucosal damage associated with a significant decrease of VH (p < 0.0001) and M/C (p < 0.01) on 1st and 3rd post-radiation days respectively. In contrast, group 4 rats maintained their mucosal structure and had a significant increase of VH and M/C (p < 0.0001) on post-radiation days 1 and 3. Bacterial translocation in MLN was 87.5% (p < 0.002) and 75% (p < 0.04) on 1st and 3rd post-radiation days respectively in group 3, and fell significantly to 12.5% (p < 0.002) in group 4. The data demonstrate that glutamine helps maintain the integrity of the intestinal mucosa and thereby reduces the incidence of bacterial translocation following abdominal irradiation.