Post-treatment with yiqifumai injection and its main ingredients attenuates lipopolysaccharide-induced microvascular disturbance in mesentery and ileum.

OBJECTIVE: To investigate the effect of Yiqifumai injection (YQFM), a compound Chinese medicine, and its main active ingredients on lipopolysaccharide (LPS)-induced microvascular disturbance in mesentery and ileum. METHODS: Rats were infused with LPS (5 mg/kg/h) for 90 min. Thirty minutes after initiation of LPS administration, YQFM (160 mg/kg/h), Rb1 (5 mg/kg/h), Sch (2.5 mg/kg/h), or Rb1+Sch (5 mg/kg/h + 2.5 mg/kg/h) was infused until 90 min. Human umbilical vein endothelial cells (HUVECs) were incubated with LPS (100 ng/ml) for 90 min. YQFM (1 mg/ml), Rb1 (100 µM), Sch (100 µM), or Rb1+Sch (200 µM) was added 30 min after initiation of LPS stimulation. RESULTS: Yiqifumai injection and Rb1+Sch inhibited mesenteric venule hyperpermeability, suppressed microvillar erosion and submucosal edema, and protected claudin-5 from downregulation and interleukin-1ß from upregulation in ileal tissues after LPS. Study in HUVECs confirmed the effect of YQFM and Rb1+Sch on JAM-1 after LPS and revealed a similar effect on other junction proteins. Moreover, YQFM and Rb1+Sch attenuated the dysfunctional energy metabolism and the activation of TLR-4/Src/NF-κB signaling with Rb1 and Sch being partially effective. CONCLUSION: These results demonstrated the beneficial effect of post-treatment with YQFM, which is attributable to its main ingredient Rb1 and Sch, and likely mediated by targeting TLR-4/Src/NF-κB signaling pathway.

Impact of electrocautery and hyperthermic intraperitoneal chemotherapy on intestinal microvasculature in a murine model.

BACKGROUND: Electrocautery (EC) is used during cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Using a murine model, we studied the effect of HIPEC on small bowel EC lesions and surrounding normal tissues. METHODS: Thirty-two rats were divided into five groups: a control group with EC lesions; EC plus intraperitoneal heated 5% dextrose (D5W); EC plus oxaliplatin (OXA, 460 mg/m(2)); EC plus mitomycin C 10 mg/m(2) (MMC10); EC plus MMC 35 mg/m(2) (MMC35). EC lesions and surrounding tissue microvasculature were analysed after intravenous injection of fluorescein. RESULTS: In the ileum OXA significantly reduced EC lesions microvasculature compared with the control group; MMC10 caused greater reduction than the control, D5W and MMC35 groups. Surrounding tissue microvasculature was significantly reduced by MMC35 exposure when compared to the control, OXA or MMC10 groups. In the jejunum EC injuries exposed to OXA or MMC10 had significantly reduced microvasculature compared to the control, heated D5W and MMC35 groups. Surrounding tissue microvasculature was significantly reduced by MMC35 exposure when compared to the OXA group. There was no significant microvasculature difference between the EC lesions made before or after HIPEC. CONCLUSION: HIPEC with OXA and MMC10 potentiates small bowel wall EC injuries. MMC35 reduces surrounding unharmed tissue microvasculature. There was no effect of hyperthermia alone on microvasculature.

Effects of Proanthocyanidins on Intestinal Motility Disturbance Following Intestinal Ischemia/Reperfusion.

PURPOSE: To investigate the potential protective effects of Proanthocyanidins(PAs) on intestinal motility disturbance following intestinal ischemia/reperfusion (I/R). MATERIALS AND METHODS: Male rats were divided into four groups: Sham, I/R, I/R+PA100 and I/R+PA200. Sham group underwent laparotomy without ligation, the others were subjected to intestinal ischemia for 1 h and reperfusion 4 h. Rats in the I/R+PA100 group received PAs (100 mg/kg/d) for 5 days prior to I/R, while rats in the I/R+PA200 group received PAs (200 mg/kg/d). After reperfusion, using an electrophysiology instrument measured ileal slow wave. Ileal specimens were obtained to determine contractility, tissue levels of Bax, Bcl-2, and Caspase-3 and evaluate histopathological changes. In addition, blood sample was obtained to determine serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels. RESULTS: Intestinal I/R caused severe histopathological injury including mucosal erosions, inflammatory cell infiltration, necrosis, and hemorrhage. Both PAs treatment decreased mucosal pathological impairment in comparison with the I/R group (p < .05) in light microscopic evaluations. In both PAs-treated groups, Bax and Caspase-3 expression were decreased compared to I/R group, while the Bcl-2 expression increased (p < .05), which was similarly the case for serum SOD activity demonstrated significant enhance (p < .05) and decline in MDA levels in comparison with I/R group (both p < .05). Moreover, PAs treatment was more efficient in attenuating serum MDA levels of intestinal I/R (both p < .05). And the contractile amplitude and frequency of slow wave in I/R+PA100 and I/R+PA200 groups were higher than I/R group (both p < .05). CONCLUSIONS: PAs improve intestinal motility disturbance following intestinal I/R by alleviating oxidative stress and apoptosis.

Large, segmental, circular vascular malformation of the small intestine (in a female toddler with hematochezia): unusual presentation in a child.

BACKGROUND: Failure to thrive and hematochezia in children may be alarm signs warranting endoscopy. In contrast, vascular malformations of the small intestine are uncommon in this age group. We report on a female toddler in whom various imaging techniques revealed an unusually large segmental vascular malformation of the ileum as the cause of the child's main clinical symptoms. CASE PRESENTATION: A 19 months old girl presented with severe anemia (Hb 3 mmol/l), failure to thrive and chronic diarrhea. Diagnostics for intestinal blood loss and pathogens were negative. The child had duodenoscopy, also for histological diagnosis of celiac disease, with negative results. A dietary protocol was suggestive for inadequate iron intake and she was supplemented. After symptomless four-months the child presented again, now with mild abdominal pain and, for the first time, hematochezia. An orienting abdominal ultrasound (US) study showed a suspicious tumorous bowel condition. A subsequent detailed abdominal US supplemented by a saline enema during investigation (i.e., "hydrocolon", to improve outlining of the formation's localization) revealed a large circumferential cystiform vascular mass of the ileum causing segmental ileal obstruction.Complementing preoperative abdominal hydro-MRI, planned based on the findings of the US study, confirmed the suspected vascular malformation of the ileum and exquisitely outlined the extent, location and anatomy.The patient was successfully operated laparoscopically, the affected ileum segment with the mass was completely removed as proven by histology, and the child recovered well. CONCLUSIONS: The huge segmental vascular malformation of the distal ileum described here is an extreme rarity in young children. Although the reported child's presenting symptoms malabsorption and malnutrition could have been responsible for its severe anemia, this was obviously caused by blood losses from the ileal vascular malformation. It was due to incipient abdominal pain rather than hematochezia that abdominal US was performed and proved crucial for correctly diagnosing this rare malformation. Even in this extensive case detailed imaging work-up including adapted MRI added all information necessary for minimal invasive laparoscopic en bloc resection.

Effects of exogenous vasoactive intestinal peptide on mesenteric lymph pathway during early intestinal ischemia-reperfusion injury in rats.

Mesenteric lymph pathway serves as the primary route by which gut injury leads to systemic inflammation and distant organ injury. The inflammation of the intestinal tract is partially mediated by vasoactive intestinal peptide (VIP). Therefore, the aim of this study was to test whether exogenous VIP affects mesenteric lymph pathway during early intestinal ischemia-reperfusion (IIR) injury. Rats were randomized into control, control+VIP, IIR and IIR+VIP groups. The observation of mesenteric lymph flow was carried out by cannulation of mesenteric lymphatics. The distribution of in vivo lymphocyte trafficking was performed by (51)Cr labeled lymphocytes and was measured by γ-counter. Endotoxin concentration was assayed using the limulus test kit and TNF-α level was detected by ELISA. When IIR injury treated with VIP, the volumes of lymph flow increased by 80%, which caused the number of lymphocytes exiting in mesenteric lymphatic increased by 50% while the proportion of (51)Cr-lymphocytes in Peyer's patches, intestinal effector tissues, mesenteric nodes, large intestine, stomach decreased by 58%, 51%, 58%, 63%, 64% respectively at the 6th h after reperfusion following intestinal ischemia. Meanwhile, endotoxin and TNF-α levels in intestinal lymph decreased by 51% and 83%. These results suggest that exogenous VIP ameliorates IIR induced splanchnic organ damage via inhibition of toxic mediators reaching systemic circulation and reinforcement of the effective immune responses in gut-associated lymphoid tissues (GALT).

Fish oil increases blood flow in the ileum during chronic feeding in rats.

Benefits of enteral feeding with immune-enhancing diets (IEDs) depend on route, timing, and composition. We hypothesized that chronic enteral feeding with certain individual immunonutrients would enhance gastrointestinal blood flow. Male rats were fed a standard enteral diet supplemented with immunonutrients for 5 days before study. Groups were (1) standard rat chow, (2) liquid control diet (CD) alone (CD), (3) CD + fish oil, (4) CD + L-arginine, and (5) CD + RNA fragments. Whole organ blood flow distribution was measured by colorimetric microsphere technique in antrum, small intestine (in thirds), colon, liver, spleen, pancreas, and kidneys. Chronic feeding for 5 days with CD + fish oil increased blood flow in the distal third of the small intestine compared with CD alone, whereas feeding with CD + L-arginine decreased blood flow in the small intestine (all segments) compared with CD alone. Acute gavage of CD + L-arginine or CD + fish oil increased blood flow in the proximal and middle third of the small intestine compared with CD alone. Control diet + RNA increased blood flow in the proximal small intestine compared with CD alone. These findings support prior acute feeding studies with CD, CD + individual immunonutrients, or IED. Our current data suggest that blood flow benefits associated with fish oil persist during chronic feeding in rats. Enhanced gastrointestinal perfusion might partially explain the benefits of early enteral feeding with IEDs not seen with regular enteral diets and parenteral immunonutrient delivery.

Protective effects of Ginkgo biloba extract in rats with hypoxia/reoxygenation-induced intestinal injury.

BACKGROUND: The purpose of this study is to investigate the protective effects of Ginkgo biloba extract (EGb 761) in rat pups with hypoxia/reoxygenation (H/R)-induced bowel injury. METHODS: One-day-old Wistar albino rat pups (n = 21) were randomly divided into 3 groups: group 1 (control, untreated and not exposed to H/R, n = 7), group 2 (untreated but exposed to H/R, n = 7), and group 3 (EGb 761 + H/R, n = 7). Ginkgo biloba extract was administered (100 mg/kg per day, subcutaneously) to group 3 for 3 days. On the fourth day, all animals except controls were exposed to H/R and were killed 6 hours after H/R. Histopathologic injury scores (HIS), malondialdehyde, glutathione (GSH), GSH-peroxidase (Px) activities, and nitric oxide (NO) levels were measured on intestinal samples. RESULTS: Although the control group had normal HIS, group 2 had grade 3 HIS. In contrast, group 3 had minimal HIS, and these results were significantly better than those of group 2 (P < .001). Malondialdehyde and NO levels of group 3 were significantly lower than those of group 2 (P < .01). Glutathione and GSH-Px activities of group 1 were higher than those of groups 2 and 3 (P < .05). However, there were no significant differences for GSH and GSH-Px activities between groups 2 and 3. CONCLUSIONS: This study showed that hypoxia and NO contributed to the pathogenesis of H/R-induced intestinal injury and that prophylactically administered EGb 761 had a protective effect on bowel injury.

Lemon grass (Cymbopogon citratus) ameliorates murine spontaneous ileitis by decreasing lymphocyte recruitment to the inflamed intestine.

OBJECTIVE: Aberrant leukocyte migration has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Lemon grass is a natural herb that contains citral, which suppresses lymphocyte expression of gut homing molecules by inhibiting retinoic acid formation. We therefore hypothesized that lemon grass intake could ameliorate excess migration of leukocytes to the inflamed intestine in chronic ileitis. METHODS: Migration of fluorescence-labeled T cells to microvessels in the ileal mucosa of SAMP1/Yit mice was monitored using intravital microscopy. In some mice, lemon grass solution was administered for two weeks. For evaluation of the effects on chronic ileitis, mice were treated with lemon grass for 26 weeks. RESULTS: Surface expression of beta7 and CCR9 on T lymphocytes was stronger in SAMP1/Yit mice than in AKR/J mice. Lemon grass treatment attenuated the surface expression of beta7-integrin and CCR9. The number of adherent lymphocytes to microvessels in chronic inflamed ileum was significantly few when lymphocytes were isolated from lemon grass treated mice. Long-term lemon grass treatment improved ileitis in SAMP1/Yit mice, which was assessed by body weight, histological changes and the infiltration of beta7-positive cells. CONCLUSION: Lemon grass ameliorated ileitis through decreasing lymphocyte migration by inhibiting beta7-expression, suggesting its therapeutic usefulness for IBD.

Protective effects of Nigella sativa on intestinal ischemia-reperfusion injury in rats.

BACKGROUND: In previous studies, it has been demonstrated that Nigella Sativa (NS) has protective effects against ischemia reperfusion injury on various organs. However, its protective effects on intestinal tissue against ischemia reperfusion injury are unclear. We aimed to determine whether NS prevents intestinal ischemia-reperfusion injury in rats. MATERIALS AND METHODS: Thirty rats were divided into three groups as sham (group 1), control (group 2), and NS-treatment group (group 3). All rats underwent intestinal ischemia for 60 min followed by a 60-min period of reperfusion. Rats were intraperitoneally infused only 0.9% saline solutions in group 2. Rats in the group 3 received NS (0,2 mL/kg) intraperitoneally, before ischemia and before reperfusion. Total antioxidant capacity (TAC), catalase (CAT), total oxidative status (TOS), oxidative stress index (OSI), and myeloperoxidase (MPO) in ileum tissue were measured. Also, ileum tissue histopathology was evaluated by a light microscope. RESULTS: The levels of liver enzymes in group 3 were significantly lower than those in group 2 (p <.01). TAC and CAT activity levels in ileum tissue were significantly higher in group 3 than in group 2. TOS, OSI, and MPO in ileum tissue were significantly lower in group 3 than group 2 (p <.05 for TOS and MPO; p < .01 for OSI). Histological tissue damage was milder in the NS treatment group than in the control group. CONCLUSION: Our results suggest that NS treatment protected the rat's intestinal tissue against intestinal ischemia-reperfusion injury.

[Ischemic anastomotic bowel perforation during treatment with bevacizumab 10 months after surgery]. / Ischämische Anastomosenperforation im Bereich einer Ileotransversostomie unter Therapie mit Bevacizumab.

BACKGROUND: Bevacizumab (Avastin) is a monoclonal antibody against vascular endothelial growth factor (VEGF) receptor that has demonstrated increased overall survival when added to standard chemotherapy regimens in patients with metastatic colorectal cancer. Gastrointestinal perforation is a known risk factor of unknown etiology associated with the use of bevacizumab. OBJECTIVE: We report a 61-year-old woman with adenocarcinoma of the colon ascendens who underwent hemicolectomy and adjuvant chemotherapy with oxaliplatin, 5-fluorouracil, and leucovorin. Eight months after the operation, we started therapy with bevacizumab combined with irinotecan, 5-fluorouracil, and leucovorin due to disease progression. Two months after completion of this therapy, ischemic anastomotic bowel perforation occurred and a resection of the anastomosis was performed. Because of anastomotic insufficiency 8 days later, a further revision had to be done and the terminal ileum and the colon were brought out through a stoma. DISCUSSION: This case is unusual because the time interval between the primary operation and the application of bevacizumab is regarded as safe with regard to the risk of perforation. An ischemic genesis of the perforation was considered on the basis of the histopathological workup. In case of perforations during therapy with bevacizumab, a safe surgical approach should be preferred, i.e., a transient stoma instead of a primary reconstruction of the bowel passage.

Effects of sodium nitroprusside on splanchnic microcirculation in a resuscitated porcine model of septic shock.

BACKGROUND: We tested the hypothesis that sodium nitroprusside (SNP) might improve the impairment of hepatosplanchnic microcirculatory blood flow (MBF) in septic shock. METHODS: Fourteen pigs were anaesthetized and their lungs mechanically ventilated. Sepsis was induced with i.v. infusion of live Pseudomonas aeruginosa [1x10(8) colony forming units (CFU) ml(-1) kg(-1)] for 1 h. Sixty minutes later, the animals received in a random succession either SNP or normal saline for 30 min. Mean arterial pressure (MAP), cardiac index (CI), mean pulmonary artery pressure (MPAP), carbon dioxide tension of the ileal mucosa (PCO2; by gas tonometry), ileal mucosal and hepatic MBF by laser Doppler flowmetry, blood gases, and lactates were assessed before, during administration, and 30 min after discontinuing the test drug. RESULTS: Bacterial infusion promoted hypodynamic shock (MAP -18%, CI -33%, ileal MBF -19%, and hepatic MBF -27%), which was converted to normodynamic shock by resuscitation. During SNP infusion, ileal mucosal MBF significantly increased (+19%) compared with control (P = 0.033). Although hepatic MBF increased (+42% from baseline), this did not differ from control. In order to maintain a constant central venous pressure and MAP, fluid loading and norepinephrine (P < 0.01) were increased. Acid-base status was not altered by SNP. CONCLUSIONS: In a resuscitated porcine model of the early phase of septic shock, SNP improved ileal mucosal MBF but required a concomitant increase in fluid and norepinephrine supplements to maintain constant systemic haemodynamic parameters.

A mechanistic study of the intestinal absorption of cryptotanshinone, the major active constituent of Salvia miltiorrhiza.

The nature of intestinal absorption of most herbal medicine is unknown. Cryptotanshinone (CTS) is the principal active constituent of the widely used cardiovascular herb Salvia miltiorrhiza (Danshen). We investigated the oral bioavailability of CTS in rats and the mechanism for its intestinal absorption using several in vitro and in vivo models: 1) Caco-2 cell monolayers; 2) monolayers of MDCKII cells overexpressing P-glycoprotein (PgP); and 3) single-pass rat intestinal perfusion with mesenteric vein cannulation. The systemic bioavailabilities of CTS after oral and intraperitoneal administration at 100 mg/kg were 2.05 and 10.60%, respectively. In the perfused rat intestinal model, permeability coefficients based on CTS disappearance from the luminal perfusate (Plumen) were 6.7- to 10.3-fold higher than permeability coefficients based on drug appearance in venous blood (Pblood). Pblood significantly increased in the presence of the P-gP inhibitor, verapamil. CTS transport across Caco-2 monolayers was pH-, temperature- and ATP-dependent. The transport from the apical (AP) to the basolateral (BL) side was 3- to 9-fold lower than that from the BL to the AP side. Inclusion of verapamil (50 microM) in both AP and BL sides abolished the polarized CTS transport across Caco-2 cells. Moreover, CTS was significantly more permeable in the BL to AP than in the AP to BL direction in MDCKII and MDR1-MDCKII cells. The permeability coefficients in the BL to AP direction were significantly higher in MDCKII cells overexpressing PgP. These findings indicate that CTS is a substrate for PgP that can pump CTS into the luminal side.

Protective effect of melatonin on contractile activity and oxidative injury induced by ischemia and reperfusion of rat ileum.

Free radicals derived from molecular oxygen have been reported to be responsible for changes in motility and mucosal damage observed in intestinal ischemia-reperfusion injury. Melatonin has been considered as an antioxidant that prevents injuries resulted from I/R in various tissues. The present study was designed to determine the effect of melatonin on the contractile responses of acetylcholine (Ach) and KCl, on malondialdehyde (MDA), a product of lipid peroxidation, and reduced glutathione (GSH) levels and to assess histopathological changes in the smooth muscle of terminal ileum subjected to ischemia-reperfusion. The intestinal ischemia-reperfusion was induced by occlusion of superior mesenteric artery of rat for 30 min, followed by a period of reperfusion for 3 h. Melatonin at doses of 10 or 50 mg/kg was administered via the tail vein in 5 min prior to reperfusion. Following reperfusion, segments of terminal ileum were rapidly taken and transferred into isolated organ bath and responses to Ach and KCl were recorded. Samples of terminal ileum were also taken for measuring the MDA and GSH levels. EC50 values of these contracting substances were seriously reduced in the ischemia-reperfusion group compared to that of the sham-operated control group. The decreased contraction response to Ach and KCl was significantly ameliorated by a dosage of 50 mg/kg of melatonin, while not by a dosage of 10 mg/kg. Similar pattern of the effect was observed in the tissue levels of MDA and GSH as well as in histological improvement. Melatonin appeared to be restoring the amounts of tissue MDA and GSH back to about control levels. These results suggest that the high dose of melatonin not only physiologically but also biochemically and morphologically could be useful to normalize contractility injured by oxidative stress in intestinal ischemia-reperfusion.

Cecal volvulus: a report of two cases occurring after the antegrade colonic enema procedure.

BACKGROUND: Many children with chronic constipation and fecal incontinence have benefited from the antegrade colonic enema (ACE) procedure. Routine antegrade colonic lavage often allows such children to avoid daytime soiling. This report describes 2 children in whom the ACE procedure was complicated by a cecal volvulus. METHODS: A retrospective review of 164 children with an ACE procedure was conducted. Two instances of cecal volvulus were identified. RESULTS: The first child presented with abdominal pain and difficulty intubating the ACE site. Over the subsequent day, his pain worsened, and radiographs depicted a colonic obstruction. At laparotomy, a cecal volvulus resulting in bowel necrosis was observed, and resection of the affected bowel and appendix (in the right lower quadrant) and end ileostomy was required. He subsequently had the stoma closed and a new ACE constructed with a colon flap. The second child presented with shock and evidence of an acute abdomen. At laparotomy, a cecal volvulus was noted, and ileocolic resection including the ACE stoma (located at the umbilicus) and an ileostomy and Hartmann pouch was performed. He had a protracted hospital course requiring ventilator and inotropic support. He currently is well and still has an ileostomy stoma. CONCLUSIONS: A high index of suspicion for a potentially life-threatening cecal volvulus should be maintained in children undergoing an ACE procedure who present with abdominal pain, evidence of bowel obstruction, or difficulty in advancing the ACE irrigation catheter.

Difference in rates of net portal absorption between crystalline and protein-bound lysine and threonine in growing pigs fed once daily.

Net portal absorption of AA during the 6-h postprandial period was measured in eight gilts (48.5 +/- 1.6 kg BW) in a crossover design. The pigs had chronic catheters placed in the portal vein, carotid artery, and ileal vein, and were trained to consume 1.2 kg of a standard grower diet once daily. Blood samples were taken every 30 min for 4 h and then hourly until 6 h after feeding. The first set of blood samples was taken after pigs were fed a meal of the test 16% CP corn-soybean meal diet (16% CP) or the test 12% CP corn-soybean meal diet supplemented with crystalline lysine, threonine, and tryptophan (12% CP + AA) to equal the three AA levels in the 16% CP diet. Pigs were then fed the standard diet for 2 d. Following that, blood samples were again taken after the pigs were fed a meal of the test diet that was not given to them at the first sampling period. Net portal AA absorption was calculated by multiplying porto-arterial plasma AA concentration difference by portal vein plasma flow rate (PVPF), estimated by an indicator-dilution technique employing p-aminohippuric acid as the indicator infused into the ileal vein. Plasma concentrations of lysine and threonine of pigs were affected by the diet x time interaction (P < 0.01). Portal and arterial plasma lysine and threonine concentrations in pigs attained the maximal level by 1 h postprandial when the 12% CP + AA diet was fed, but reached the peak level at 2.5 h postprandial when the 16% CP diet was given. The PVPF of pigs over the 6 h postprandial was less (P < 0.01) when the 12% CP + AA diet was given than when the 16% CP diet was fed. Net portal absorptions of lysine and threonine also were affected (P < 0.05) by time x diet interaction. The peak portal absorption of both lysine and threonine in pigs appeared at 0.5 h postprandial when the 12% CP + AA diet was given, but at 2.5 h postprandial with the feeding of the 16% CP diet. The early appearance of peak portal absorption of lysine and threonine from feeding the 12% CP + AA compared with the 16% CP diet indicates that crystalline lysine and threonine are absorbed more rapidly than protein-bound lysine and threonine in pigs fed once daily.

Hemoglobin-based oxygen carrier provides heterogeneous microvascular oxygenation in heart and gut after hemorrhage in pigs.

BACKGROUND: In this study, the hypothesis was tested that resuscitation with hemoglobin-based oxygen carriers (HBOCs) affects the oxygenation of the microcirculation differently between and within organs. To this end, we tested the influence of the volume of an HBOC on the microcirculatory oxygenation of the heart and the gut serosa and mucosa in a porcine model of hemorrhage. METHODS: In anesthetized open-chested pigs (n = 24), a controlled hemorrhage (30 mL/kg over 1 hour) was followed by resuscitation with 10, 20, or 30 mL/kg diaspirin-crosslinked hemoglobin (DCLHb) or isovolemic resuscitation with 30 mL/kg of a 6% hydroxyethyl starch solution (HAES). Measurements included systemic and regional hemodynamic and oxygenation parameters. Microvascular oxygen pressures (microPO2) of the epicardium and the serosa and mucosa of the ileum were measured simultaneously by the palladium-porphyrin phosphorescence technique. Measurements were obtained up to 120 minutes after resuscitation. RESULTS: After hemorrhage, a low volume of DCLHb restored both cardiac and intestinal microPO2. Resuscitation of gut microPO2 with a low volume of DCLHb was as effective as isovolemic resuscitation with HAES. Higher volumes of DCLHb did not restore cardiac microPO2, as did isovolemic resuscitation with HAES, but increased gut microPO2 to hyperoxic values, dose-dependently. Effects were similar for the serosal and mucosal microPo2. In contrast to a sustained hypertensive effect after resuscitation with DCLHb, effects of DCLHb on regional oxygenation and hemodynamics were transient. CONCLUSION: This study showed that a low volume of DCLHb was effective in resuscitation of the microcirculatory oxygenation of the heart and gut back to control levels. Increasing the volume of DCLHb did not cause an additional increase in heart microPO2, but caused hyperoxic microvascular values in the gut to be attained. It is concluded that microcirculatory monitoring in this way elucidates the regional behavior of oxygen transport to the tissue by HBOCs, whereas systemic variables were ineffective in describing their response.

Dose-dependent effects of ethyl pyruvate in mice subjected to mesenteric ischemia and reperfusion.

OBJECTIVE: We previously showed that infusing rats with a solution of ethyl pyruvate ameliorates intestinal mucosal injury after mesenteric ischemia and reperfusion. Ethyl pyruvate also has been shown to inhibit the expression of various pro-inflammatory cytokines in several animal models of critical illness, but dose-response relationships have not been investigated. DESIGN: Anesthetized C57BL/6 mice were subjected to 60 min of mesenteric ischemia followed by 60 min of reperfusion. After 55 min of ischemia, groups of mice were treated with normal saline or graded bolus doses of ethyl pyruvate dissolved in a calcium-containing balanced salt solution. Some animals (i.e., those in the sham group) were subjected to the anesthetic, but not mesenteric ischemia/reperfusion. Gut mucosal permeability was assessed using an everted gut sac technique. SETTING: University research laboratory. MEASUREMENTS AND RESULTS: Mesenteric ischemia/reperfusion significantly increased ileal mucosal permeability to the hydrophilic macromolecule, fluorescein isothiocyanate dextran (molecular mass 4,000 Da). Whereas the lowest dose of ethyl pyruvate evaluated (17 mg/kg) had no effect on gut mucosal permeability, the two highest doses tested (50 and 150 mg/kg) significantly ameliorated the development of ischemia/reperfusion-induced mucosal hyperpermeability to about the same extent. The two highest doses of ethyl pyruvate also significantly ameliorated deficits in ileal serosal and mucosal and hepatic surface microvascular perfusion induced by mesenteric ischemia/reperfusion. Ethyl pyruvate inhibited post-ischemia/reperfusion hepatic NF-kappaB activation and TNF mRNA expression in a dose-dependent fashion. CONCLUSION: Doses of ethyl pyruvate equal to or greater than 50 mg/kg ameliorate inflammation, microvascular hypoperfusion and gut mucosal damage induced by mesenteric ischemia/reperfusion in mice.

Genistein replacement therapy for vasodilation disorder in bilateral ovariectomized rats.

The objective of this study is to examine the effects of genistein on endothelial dysfunction in bilateral ovariectomized rats. Female Wistar rats were subjected to a bilateral ovariectomy (OVX rat). The animals were divided into three groups: sham treated with vehicle (DMSO 100 microliters/day, Shamveh), OVX treated with vehicle (DMSO 100 microliters/day, OVXveh), and OVX treated with genistein (0.25 mg/kg BW/day, OVXgen). Mean arterial pressure (MAP), heart rate (HR), body weight (BW), uterine weight and plasma E2 were monitored at 4-week after the treatment. We investigated the endothelium-dependent and -independent vasorelaxation by using acetylcholine (Ach 10(-6) M) and sodium nitroprusside (SNP 10(-7) M), respectively. The experimental results indicated that the uterine weights of all OVX rats were significantly decreased as compared to the sham groups (OVXveh = 0.007+/-0.004 g, OVXgen =0.003+/-0.001 g, Shamveh =0.017+/-0.001 g). MAP of OVXveh group was significantly increased compared to the Sham group (OVXveh=139.99+/-7.50 mmHg, Shamveh =118.10+/-19.33 mmHg, p<0.05). No significant increase in MAP was observed in OVXgen (OVXgen =123.33+/-8.61 mmHg; p<0.05). HR showed no significant difference among those groups. The present study of vasodilator responses demonstrated only the significant decrease in endothelium-dependent, not for endothelium-independence, in OVX rats, while the treatment of genistein could significantly attenuate this abnormality (OVXveh =3.03+/-3.99%, Shamveh =45.46+/-3.59%, OVXgen =33.52+/-3.25% in % change of vessel diameter). The present findings suggest that genistein could be used as a therapeutic agent for menopausal vascular complications.

Selenium pretreatment prevents bacterial translocation in rat intestinal ischemia/reperfusion model.

Protective role of selenium against free radical damage was first demonstrated in the heart and this effect was further questioned in other systems. In the present study, the effects of exogenously administered selenium on intestinal fine morphology, lipid peroxidation, and bacterial translocation (BT) in experimental intestinal ischemia/reperfusion (I/R) model were examined. Thirty-two male Wistar rats weighing 250-300 g were randomized into four groups. Sham group (n=8) underwent laparotomy only. In the I/R group (n=8), laparotomy was performed and the superior mesenteric artery was occluded using an atraumatic microvascular clamp for 30 min. In corresponding selenium-treated groups (n=8 each), sodium selenate was given 0.2 mg kg(-1)day(-1) intraperitoneally (i.p.) for 3 consecutive days, prior to surgery for either laparotomy only or with I/R. Twenty-four hours later, tissue samples from liver, spleen, and mesenteric lymph nodes were obtained under sterile conditions for microbiological analysis and further evaluation of I/R-induced intestinal injury. Ileum samples were fixed in 10% formaldehyde for histopathological evaluation. In the I/R group, the incidence of bacteria-isolated mesenteric lymph nodes, spleen, and liver was significantly higher than other groups (P<0.05). Selenium supplementation prevented I/R-induced BT and significantly reduced the I/R-induced intestinal injury (P<0.05). Tissue MDA levels from the ileum specimens of selenium-treated rats were significantly lower than that of the I/R group (P<0.05). Our results provide evidence that the relationship between BT and lipid peroxidation in intestinal tissue is crucial. Selenium pretreatment reduces lipid peroxidation which contributes to the maintenance of intestinal mucosal integrity.

Immune-enhancing enteral diet selectively augments ileal blood flow in the rat.

BACKGROUND: Clinical studies show that immune-enhancing enteral diets (IED; with L-arginine, fish oil, and RNA fragments) decrease the rate of sepsis and shorten the length of hospital stay after the start of enteral feeding. These beneficial effects are dependent on the route of administration (enteral vs parenteral) and on the nutrient composition (IED vs standard diets). Gut exposure to an IED seems to preserve and/or augment intestinal mucosal immunity. However, nutrient absorption stimulates gut blood flow in a nutrient-specific manner (i.e., postprandial hyperemia). We hypothesized that an IED would initiate a different pattern of whole organ blood flow compared to a standard diet. This suggests that a mechanism for the protective effect of IED might be the preferential augmentation of gut blood flow to gut-associated lymphoid tissue (GALT) or mucosa-associated lymphoid tissue (MALT). METHODS: Male Sprague-Dawley rats (200-225 g) were anesthetized and cannulated for colorimetric microsphere determination of blood flow distribution (with the phantom organ technique). Animals received gastric gavage (2 ml) of an IED (Impact; Novartis) or an isocaloric, isonitrogenous control diet (Boost; Mead-Johnson). Blood flow to the antrum, duodenum, jejunum, ileum, colon, liver, kidneys, and spleen was determined at baseline and 30, 60, 90, and 120 min after gavage. RESULTS: Baseline blood flows to the left and right kidneys were within 10%, indicating the technical integrity of the microsphere technique and assay. Control diet augmented blood flow compared to IED in the antrum, duodenum, jejunum, and spleen. Conversely, IED gavage stimulated a delayed and sustained hyperemic response in the ileum. IED also increased hepatic blood flow early (30 min). IED increased blood glucose levels compared to control diet at 30, 60, and 90 min, suggesting enhanced nutrient absorption. CONCLUSIONS: These data show that blood flow distribution depends on nutrient composition and that IED preferentially augments blood flow to the ileum. Since the terminal jejunum and ileum contain much of the GALT, our data suggest that a mechanism for enterally stimulated mucosal immunity involves selective perfusion of the terminal ileum during IED nutrient absorption.