Reduced fasting periods increase intestinal permeability in chickens.

Fasting of up to 24 hr has been shown to increase intestinal permeability (IP) in chickens. The aim of this study was to determine whether fasting duration of 4.5 and 9 hr increased IP and whether l-glutamine (a non-essential amino acid) supplementation before fasting provided some protection of barrier function as shown in other species. Ross 308 male broilers (n = 96) were fed either a control diet or the same diet supplemented with 1% glutamine from d0 to d38 post-hatch. On d37, the birds were assigned to single-bird metabolism cages and were fasted for either 0, 4.5, 9 or 19.5 hr. This study design was 2 × 4 factorial with two levels of glutamine and four levels of fasting. Birds in the 0-hr fasting group had free access to feed. All birds had ad libitum access to water. To measure IP on day 38, following their respective fasting periods, birds were administered two separate oral gavages of fluorescein isothiocyanate dextran (FITC-d) followed by lactulose, mannitol and rhamnose (LMR) sugars, 60 min apart. Whole blood was collected from the jugular vein 90 min post-LMR sugar gavage. FITC-d and L/M/R ratios were measured by spectrophotometry and high-performance ionic chromatography respectively. Lipopolysaccharide (LPS) endotoxins in plasma of the birds fed the control diet were also measured using chicken-specific LPS antibody ELISA. Serum FITC-d and plasma L/M and L/R ratios for 4.5, 9 and 19.5 hr were significantly (p < .05) higher compared to the non-fasting group. However, IP was not different in the glutamine-supplemented group (p > .05) compared to the control group. LPS concentrations measured by the ELISA were below the detectable range. We conclude that fasting periods of 4.5 and 9 hr increased IP compared to non-fasted birds and dietary glutamine supplementation did not ameliorate changes in IP.

Perioperative Alanyl-Glutamine-Supplemented Parenteral Nutrition in Chronic Radiation Enteritis Patients With Surgical Intestinal Obstruction: A Prospective, Randomized, Controlled Study.

BACKGROUND: A prospective, randomized, controlled study was performed to evaluate the effects of perioperative alanyl-glutamine-supplemented parenteral nutrition (PN) support on the immunologic function, intestinal permeability, and nutrition status of surgical patients with chronic radiation enteritis (CRE)-induced intestinal obstruction. METHODS: Patients who received 0.4 g/kg/d alanyl-glutamine and isonitrogenous PN were assigned to an alanyl-glutamine-supplemented PN (Gln-PN) group and a control group, respectively. Serum levels of alanine aminotransferase and glutamine, body fat mass (FM), immunologic function, and intestinal permeability were measured before and after surgery. RESULTS: Serum glutamine levels of the Gln-PN group significantly exceeded that of the control group (P < .001; Gln-PN, baseline 460.7 ± 42.5 vs 523.3 ± 48.6 µmol/L on postoperative day 14 [POD14], P < .001; control, baseline 451.9 ± 44.0 vs 453.8 ± 42.3 µmol/L on POD14, P = .708). Lactulose/mannitol ratios of both groups decreased over time (Gln-PN, baseline 0.129 ± 0.0403 vs 0.024 ± 0.0107 on POD1 4; control, baseline 0.125 ± 0.0378 vs 0.044 ± 0.0126 on POD14, P < .001 in both groups). CD4/CD8-positive T-lymphocyte ratios significantly rose in both groups, with significant intergroup difference (P < .001; Gln-PN, baseline 1.36 ± 0.32 vs 1.82 ± 0.30 on POD14, P < .001; control, baseline 1.37 ± 0.25 vs 1.63 ± 0.31 on POD14, P < .001). In the Gln-PN group, FM increased from 3.68 ± 1.68 kg at baseline to 5.22 ± 1.42 kg on POD14 (P < .001). FM of control group increased from 3.84 ± 1.57 kg at baseline to 5.40 ± 1.54 kg on POD14 (P < .001). However, there were no significant intergroup differences (P = .614). CONCLUSION: Gln-PN significantly boosted the immune state and decreased the intestinal permeability of CRE patients. However, Gln-PN was not superior to standard PN in improving the nutrition state and intestinal motility of surgical patients with CRE-induced intestinal obstruction.

Dietary long-chain PUFA enhance acute repair of ischemia-injured intestine of suckling pigs.

Infant formula companies have been fortifying formulas with long-chain PUFA for 10 y. Long-chain PUFA are precursors of prostanoids, which stimulate recovery of intestinal barrier function. Supplementation of milk with PUFA increases the content of arachidonic acid (ARA) in enterocyte membranes; however, the effect of this enrichment on intestinal repair is not known. The objective of these experiments was to investigate the effect of supplemental ARA on intestinal barrier repair in ischemia-injured porcine ileum. One-day-old pigs (n = 24) were fed a milk-based formula for 10 d. Diets contained no PUFA (0% ARA), 0.5% ARA, 5% ARA, or 5% EPA of total fatty acids. Following dietary enrichment, ilea were subjected to in vivo ischemic injury by clamping the local mesenteric blood supply for 45 min. Following the ischemic period, control (nonischemic) and ischemic loops were mounted on Ussing chambers. Transepithelial electrical resistance (TER) was measured over a 240-min recovery period. Ischemia-injured ileum from piglets fed 5% ARA (61.0 ± 14%) exhibited enhanced recovery compared with 0% ARA (16 ± 14) and 0.5% ARA (22.1 ± 14)-fed pigs. Additionally, ischemia-injured ileum from 5% EPA (51.3 ± 14)-fed pigs had enhanced recovery compared with 0% ARA-fed pigs (P < 0.05). The enhanced TER recovery response observed with ischemia-injured 5% ARA supplementation was supported by a significant reduction in mucosal-to-serosal flux of (3)H-mannitol and (14)C-inulin compared with all other ischemia-injured dietary groups (P < 0.05). A histological evaluation of ischemic ilea from piglets fed the 5% ARA showed reduced histological lesions after ischemia compared with the other dietary groups (P < 0.05). These data demonstrate that feeding elevated levels of long-chain PUFA enhances acute recovery of ischemia-injured porcine ileum.

Modeling of the in vivo kinetics of antioxidants delineates suitable parameters for selecting potential antioxidant adjuvants for cancer therapy.

To find in vivo behaviors of an antioxidant when used as an adjuvant cancer therapy, a more detailed integrated pharmacokinetic scheme is needed. Major reaction parameters associated with the sequential routes from ingestion to decay of an antioxidant were used in mathematical analysis, which included absorption rate coefficient k(a), quenching rate coefficient of the antioxidant k(q1) and tissue quenching rate coefficient k(r). The model was then treated with computer simulation using cited decay rate coefficients and some assumed parameters. When intestinal absorption rate coefficient k(a) becomes larger, retention time of antioxidant in plasma would be prolonged. moreover, k(a) had no effect on either quenching ability of antioxidants or tissue recovering capability. in quenching plasma ROS, the larger the quenching coefficient k(q1), the shorter peak- and the life-times would be for the secondary free radicals that are formed in primary quenching. Conclusively, it is suggestive to prescribe an antioxidant therapy with an appropriate values of k(a) and larger values of k(q1).

Glutamine and recombinant human growth hormone protect intestinal barrier function following portal hypertension surgery.

AIM: To evaluate the effects of combined treatment of glutamine (Gln) and recombinant human growth hormone(rhGH) on intestinal barrier function following portal hypertension surgery. METHODS: This study was designed as a prospective, randomized and controlled clinical trial. Forty two patients after portal hypertension surgery were randomly assigned into 2 groups: control group (n = 20) and supplemental group (adding Gln and rhGH, n = 22). Every patient received isocaloric and isonitrogenous standard total parenteral nutrition (TPN) starting 3 d after surgery for 7 d. Blood samples were obtained before surgery and at the 3rd and 10th day postoperatively. Host immunity was evaluated by measuring levels of CD4, CD8, CD4/CD8, IgG, IgM and IgA, and the inflammatory responses were determined by assessing IL-2, TNF-alpha and C-reactive protein (CRP) levels. Intestinal permeability and integrity was evaluated by L/M test and histological examination, respectively. RESULTS: On postoperative d 10, CD4, CD4/CD8, IgG and IL-2 levels in supplemental group were significantly higher than those in control group (33.7 +/- 5.5 vs 31.0 +/- 5.4, P < 0.05, (1.17 +/- 0.32 vs 1.05 +/- 0.15, P < 0.05, 13.94 +/- 1.09 vs 12.33 +/- 1.33, P < 0.05, and 368.12 +/- 59.25 vs 318.12 +/- 45.65, P < 0.05, respectively), whereas the increase in serum TNF-alpha concentration was significantly reduced (41.02 +/- 27.56 vs 160.09 +/- 35.17, P < 0.05). The increase in L/M ratio was significantly lower in the supplemental group than in the control group (0.0166 +/- 0.0017 vs 0.0339 +/- 0.0028, P < 0.05). Moreover, mucosal integrity in the supplemental group was better than in the control group. CONCLUSION: Postoperative administration of TPN supplemented with Gln and rhGH in patients after portal hypertension surgery improves immune function, modulates inflammatory response, prevents the intestinal mucous membrane from atrophy and preserves intestinal integrity.

Formula-feeding reduces lactose digestive capacity in neonatal pigs.

The intestine of newborn pigs develops rapidly during the first days postpartum. We investigated if feeding milk replacer (infant formula) as an alternative to colostrum has compromising effects on nutrient digestive function in the neonatal period. Nineteen piglets born at term were assigned to one of four treatments: (1) newborn controls; (2) natural suckling for 24 h; (3) tube-fed formula for 24 h; (4) tube-fed porcine colostrum for 24 h. All three fed groups showed significant increases in small-intestinal and colonic weights, villous heights and widths, maltase and aminopeptidase A activities, and decreases in dipeptidylpeptidase IV activity, relative to newborn pigs. Following oral boluses of mannitol, lactose or galactose, formula-fed pigs showed significantly reduced plasma levels of mannitol and galactose compared with colostrum-fed pigs. Activity of intestinal inducible NO synthase and plasma levels of cortisol were significantly increased, whereas intestinal constitutive NO synthase and alpha-tocopherol were decreased in formula-fed pigs compared with colostrum-fed pigs. Although formula-fed pigs only showed minor clinical signs of intestinal dysfunction and showed similar intestinal trophic responses just after birth, as those fed colostrum, lactose digestive capacity was markedly reduced. We conclude that formula-feeding may exert detrimental effects on intestinal function in neonates. Formula-induced subclinical malfunction of the gut in pigs born at term was associated with altered NO synthase activity and antioxidative capacity.

Sensitive and specific photometric determination of mannitol in human serum.

Mannitol is an osmotically active polyalcohol often present in fluids used for irrigation of exposed tissue during minimal invasive surgery. Since this polyol normally is not detected in human plasma to any significant extent, it may be used as a laboratory marker of absorption of mannitol-containing irrigative fluids during surgery. For this aim, we developed a photometric assay of mannitol in human blood or serum that may be performed in a near-patient setting. Following deproteinization of the sample with trichloroacetic acid, the supernatant is mixed with NAD+ and a commercially available preparation of mannitol 2-dehydrogenase and is incubated at pH 7.8 and at 37 degrees C for 30 to 60 minutes. At the end of the incubation period the solution is appropriately diluted and the concentration of NADH formed by oxidation of mannitol is determined photometrically at 340 nm. The limit of detection of serum mannitol with this assay is 0.05 mmol/l, the linear range of measurement extends to about 3 mmol/l. At analyte concentrations of 0.48, 1.38 and 3.48 mmol/l, coefficients of inter-assay variation of 12.1, 6.7 and 4.9%, respectively, were obtained. The analytical recovery of mannitol added to serum samples was close to 100%. Of 27 polyalcohols, monosaccharides and oligosaccharides tested, none exhibited a measurable substrate activity and only D-fructose significantly inhibited the oxidation of mannitol at sample concentrations above 10 mmol/l; the enzymatic reaction, however, was strongly affected by EDTA. The suitability of the assay as a routine diagnostic tool for detection and quantification of intraoperatively absorbed irrigation fluid was demonstrated by analyzing mannitol in serum samples obtained from 24 patients undergoing transurethral prostatectomy.