Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the effect of verapamil on intestinal ischemia and reperfusion (I/R) injury. Intestinal ischemia was induced by clamping the superior mesenteric artery for 30 min followed by reperfusion. Magnetic resonance spectroscopy was employed as a marker of the changes in the energy metabolism. Further, histological changes and the changes of water contents were evaluated. Recovery rates of energy metabolism after intestinal I/R were improved by verapamil, administered before and after ischemia, and tissue edema was significantly reduced with verapamil. These findings suggest that verapamil results in an improved recovery of the energy metabolism and cellular preservation, presumably by reducing the intracellular calcium influx.
 ...
PMID:Beneficial effects of verapamil on intestinal ischemia and reperfusion injury: pretreatment versus postischemic treatment. 962 16

Intestinal ischemia and reperfusion injury (I/R) is probably involved in the pathogenesis of intestinal barrier dysfunction, associated with the concomitant translocation of enteric bacteria and toxins and the potential development of multiple organ failure. The intestinal endothelial and epithelial layers play a major role preventing the entry of toxic substances from the gut, but the influence of protease-antiprotease systemic balance on these barrier functions and the relationship between epithelial DNA synthesis, apoptosis, and endothelial and epithelial barrier macromolecule permeability are not fully investigated. Endothelial and epithelial barrier macromolecular permeability, epithelial DNA synthesis, the endothelial and epithelial plasma membrane system, apoptosis and oncosis, plasma levels of proteinase inhibitors, and proenzymes were measured in rats subjected to 20 and 40 min intestinal ischemia and 1, 3, 6, or 12 h reperfusion. Endothelial permeability increased after both 20 and 40 min intestinal ischemia. Epithelial permeability significantly increased during 1-6 h reperfusion after 20 min ischemia and during 1-12 h reperfusion after 40 min ischemia. Epithelial DNA synthesis increased in animals with 20 min ischemia followed by 12 h reperfusion. Plasma levels of prekallikrein, C1-esterase inhibitor, and alpha1-macroglobulin were significantly lower following both 20 and 40 min ischemia from 3 h reperfusion and on. Apoptotic epithelial cells significantly increased in animals subjected to 20 min ischemia followed by 12 h reperfusion. The severity of reperfusion injury in the intestinal endothelial and epithelial barrier seems to correlate with the period of ischemia and the pathway of cell damage and death, together with proteinase-antiproteinase imbalance.
 ...
PMID:The influence of intestinal ischemia and reperfusion on bidirectional intestinal barrier permeability, cellular membrane integrity, proteinase inhibitors, and cell death in rats. 974 49

Intestinal ischemia/reperfusion (I/R) causes serious systemic injury, mainly from a variety of bioactive substances released from the injured intestine. To assess the possible roles of serotonin (5-hydroxytryptamine, 5-HT), a bioactive amine mainly stored in the intestine, in I/R injury, we assayed the levels of tryptophan, 5-HT, and 5-hydroxyindole acetic acid (5-HIAA) in the blood and intestine in a rat I/R model. Plasma 5-HT increased significantly over time after reperfusion; the plateau level was obtained 4 h after reperfusion and was associated with an increase in 5-HIAA. Plasma tryptophan levels declined gradually after reperfusion. The ratio of 5-HIAA/5-HT was significantly higher in I/R rats than in control rats, suggesting that elevated 5-HT was quickly metabolized in the systemic circulation. In the intestine, 5-HT decreased dramatically, whereas tryptophan increased. This phenomenon was prominent in the severely damaged intestine. These findings suggest that the injured intestine released large amounts of 5-HT, whereas its synthesis in the injured intestine was suppressed. An increase in 5-HT in the circulation may be related to various circulatory disturbances observed in humans after intestinal ischemia.
 ...
PMID:Plasma levels of 5-HT and 5-HIAA increased after intestinal ischemia/reperfusion in rats. 985 41

Intestinal ischemia-reperfusion injury is dependent on complement. This study examines the role of the alternative and classic pathways of complement and IgM in a murine model of intestinal ischemia-reperfusion. Wild-type animals, mice deficient in complement factor 4 (C4), C3, or Ig, or wild-type mice treated with soluble complement receptor 1 were subjected to 40 min of jejunal ischemia and 3 h of reperfusion. Compared with wild types, knockout and treated mice had significantly reduced intestinal injury, indicated by lowered permeability to radiolabeled albumin. When animals deficient in Ig were reconstituted with IgM, the degree of injury was restored to wild-type levels. Immunohistological staining of intestine for C3 and IgM showed colocalization in the mucosa of wild-type controls and minimal staining for both in the intestine of Ig-deficient and C4-deficient mice. We conclude that intestinal ischemia-reperfusion injury is dependent on the classic complement pathway and IgM.
 ...
PMID:Intestinal reperfusion injury is mediated by IgM and complement. 1006 8

Intestinal ischemia/reperfusion (I/R) is a serious disorder that is prevalent in elderly patients. Reactive oxygen species are implicated in the pathogenesis of intestinal I/R injury. Reactive oxygen species are also implicated in cellular senescence and aging. To test the hypothesis that aging exacerbates intestinal I/R injury, the effects of intestinal I/R on tissue injury were compared between young (3 month old) and aged (12 month old) mice. Intestinal ischemia was induced by occluding the superior mesenteric artery with a microbulldog clamp. Reperfusion was initiated by removing the clamp. Mortality due to intestinal ischemia followed by reperfusion was significantly higher in aged mice. There were no differences in the baseline levels of malondialdehyde or myeloperoxidase activity (indicators of lipid peroxidation and neutrophil infiltration, respectively) between young and aged mice. Although intestinal I/R caused a significant increase in malondialdehyde levels and myeloperoxidase activity in aged mice, similar increases were also observed in young mice. There were no significant differences in the activities of antioxidant enzymes including superoxide dismutase, glutathione peroxidase and catalase between young and aged mice that underwent sham operation. Intestinal I/R caused a significant decrease in catalase activity only in aged mice. In conclusion, our results indicate that aged mice are more susceptible to mortality due to intestinal I/R and that an age-dependent decrease in catalase activity may contribute to the observed mortality.
 ...
PMID:Effect of aging on intestinal ischemia and reperfusion injury. 1019 87

We investigated the effect of antithrombin III on 60 min warm intestinal ischemia-reperfusion (IR) injury in rats. Sprague-Dawley rats, weighing 220-250 g, were divided into three groups: group 1 sham-operated group (no IR injury, n = 8), group 2 ischemic control group (control, Ringer's lactate infused, n = 8), group 3 Antithrombin III treated group (250 U/kg before ischemia, n = 8). Intestinal ischemia was induced in rats by occluding the superior mesenteric artery for 60 min. Malondialdehyde (MDA) levels, myeloperoxidase activity (MPO) and mucosal damage were investigated after 120 min reperfusion. Elevated MDA levels and MPO activity and severe histopathological damage were observed in the control group compared with the sham group (P < 0.05). Decreased MDA levels and MPO activity and less histopathological damage were detected in group 3 compared with the control group (P < 0.05). Accumulation of lipid peroxidation products and neutrophils in mucosal tissues were significantly inhibited by antithrombin III treatment. We conclude that treatment with antithrombin III before intestinal ischemia prevents histological damage in rats.
 ...
PMID:Antithrombin III prevents 60 min warm intestinal ischemia reperfusion injury in rats. 1020 59

Intestinal ischemia necessitates rapid re-establishment of blood flow to prevent irreversible anoxic tissue damage. However, reperfusion results in additional injury as a consequence of the generation of oxygen free radicals. To date, no clear-cut marker to differentiate between ischemia versus reperfusion injury is available. In this regard, previous studies from our laboratory utilizing a rat in vitro lipid peroxidation model demonstrated that the generation of free radicals resulted in the inactivation of only the intestinal brush border alkaline phosphatase enzyme, with no effect on other membrane-bound digestive enzymes. Current studies were designed to assess the possibility of alkaline phosphatase being a specific marker of the reperfusion injury in canine and human ex vivo ischemia/reperfusion models. Small bowels harvested from canines and organ donors were subjected to ischemia followed by reperfusion. Brush border membrane enzymes, alkaline phosphatase, sucrase, maltase, and gamma-glutamyl transpeptidase were assayed in mucosal extracts from intestines with ischemia versus reperfusion. In both experimental models, there was no change in any enzyme activity with warm ischemia alone. In contrast, alkaline phosphatase activity was significantly decreased in both the canine and human reperfusion models, with no change in specific activities of sucrase, maltase, and gamma-glutamyl transpeptidase. Our data indicate that the alkaline phosphatase enzyme activity may represent a potential marker of intestinal reperfusion injury and may permit quantitative assessments of therapeutic interventions in human intestinal reperfusion injury.
 ...
PMID:Decrease in mucosal alkaline phosphatase: a potential marker of intestinal reperfusion injury. 1021 63

Intestinal ischemia-reperfusion commonly occurs in critically ill patients and may lead to the development of remote organ injury, frequently involving the lungs. In the present study, alveolar liquid clearance was studied in ventilated, anesthetized rats subjected to 45 min of intestinal ischemia followed by 3 h of reperfusion. An isosmolar 5% albumin solution was instilled into the lungs, and alveolar liquid clearance was measured from the increase in alveolar protein concentration as water was reabsorbed over 45 min. Intestinal ischemia-reperfusion resulted in a 76% increase in alveolar liquid clearance compared with the control value (P < 0.05). The stimulated alveolar liquid clearance seen after intestinal ischemia-reperfusion was not inhibited by propranolol, indicating stimulation through a noncatecholamine-dependent pathway. Intestinal ischemia-reperfusion did not result in increased intracellular cAMP levels. Amiloride inhibited similar fractions in animals subjected to ischemia-reperfusion and control animals. Administration of a neutralizing polyclonal anti-tumor necrosis factor-alpha antibody before induction of intestinal ischemia completely inhibited the increased alveolar liquid clearance observed after intestinal ischemia-reperfusion. In conclusion, our results suggest that intestinal ischemia-reperfusion in rats leads to stimulation of alveolar liquid clearance and that this stimulation is mediated, at least in part, by a tumor necrosis factor-alpha-dependent mechanism.
 ...
PMID:TNF-alpha stimulates alveolar liquid clearance during intestinal ischemia-reperfusion in rats. 1064 84

Ischemic bowel disease represents a broad spectrum of diseases with various clinical and radiologic manifestations, which range from localized transient ischemia to catastrophic necrosis of the gastrointestinal tract. The primary causes of insufficient blood flow to the intestine are diverse and include thromboembolism, nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) or magnetic resonance (MR) imaging can demonstrate the ischemic bowel segment and may be helpful in determining the primary cause. The CT and MR imaging findings include bowel wall thickening with or without the target sign, intramural pneumatosis, mesenteric or portal venous gas, and mesenteric arterial or venous thromboembolism. Other CT findings include engorgement of mesenteric veins and mesenteric edema, lack of bowel wall enhancement, increased enhancement of the thickened bowel wall, bowel obstruction, and infarction of other abdominal organs. However, regardless of the primary cause, the imaging findings of bowel ischemia are similar. Furthermore, the bowel changes simulate inflammatory or neoplastic conditions. Understanding the pathogenesis of various conditions leading to mesenteric ischemia helps the radiologist recognize ischemic bowel disease and avoid delayed diagnosis, unnecessary surgery, or less than optimal management.
 ...
PMID:CT and MR imaging findings of bowel ischemia from various primary causes. 1068 69

Intestinal ischemia/reperfusion (I/R) leads to bowel impairment via the release of reactive oxygen species (ROS) and neutrophil infiltration. In addition to modulating intestinal integrity, nitric oxide (NO(*)) inhibits neutrophil activation and scavenges ROS. Attenuated endogenous NO(*) formation may result in the accrual of these deleterious stimuli. Therefore, we determined nitric oxide synthase (NOS) activity in anesthetized rats subjected to 1 h of superior mesenteric ischemia or ischemia followed by reflow. NOS activity was measured in intestinal tissue homogenates as the conversion rate of (3)H-L-arginine to (3)H-L-citrulline. Our results demonstrate that intestinal ischemia leads to a decrease in NOS activity indicating lower NO(*) formation in the animal model. The attenuation in NOS activity was not reversed following 4 h of reperfusion. Western blot analysis revealed that the decline in enzyme activity was accompanied by reduced intestinal NOS III (endothelial constitutive NOS) expression. These findings provide biochemical evidence for impaired NO(*) formation machinery in intestinal I/R injury.
 ...
PMID:Attenuated nitric oxide synthase activity and protein expression accompany intestinal ischemia/reperfusion injury in rats. 1069 94


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>