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

Radiation enteritis (RE) is a common side effect after radiotherapy for abdominal cancer. RE pathogenesis is complicated, with no drugs available for prevention or treatments. Intestinal ischemia is a key factor in the occurrence and development of enteritis. The effect of ionizing radiation (IR) on intestinal ischemia is unknown. Deficiency of tetrahydrobiopterin (BH4) produced by GTP-cyclohydrolase 1 (Gch1) is important in ischemic diseases. This study focused on the relationship of Gch1/BH4 between intestinal ischemia in radiation enteritis. BH4 levels were analyzed by high-performance liquid chromatography in humans and rats after radiotherapy. Intestinal blood perfusion was measured by laser doppler flow imaging. Vascular ring tests determined the diastolic functions of rat mesenteric arteries. Gene, protein, and immunohistochemical staining experiments and inhibitor interventions were used to investigate Gch1 and endothelial NOS (eNOS) in rat mesenteric arteries and endothelial cells. The results showed that IR decreased BH4 levels in patients and rats after radiotherapy and decreased intestinal blood perfusion in rats. The degree of change in intestinal ischemia was consistent with intestinal villus injury. Gch1 mRNA and protein levels and nitric oxide (NO) production significantly decreased, while eNOS uncoupling in arterial and vascular endothelial cells strongly increased. BH4 supplementation improved eNOS uncoupling and NO levels in vascular endothelia after IR. The results of this study showed that downregulation of Gch1 in intestinal blood vessels after IR is an important target in RE. BH4 supplementation may prevent intestinal ischemia and improve vascular endothelial function after IR. These findings have clinical significance for the prevention and treatment of RE.
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PMID:Ionizing radiation induces BH4 deficiency by downregulating GTP-cyclohydrolase 1, a novel target for preventing and treating radiation enteritis. 3256 86

Hyperphosphatemia is a common and well-described complication of end-stage renal disease. Despite strict dietary constraints and compliance, phosphate binders such as calcium acetate and/or sevelamer carbonate are also needed to treat secondary hyperparathyroidism. This case vignette describes an underrecognized adverse effect of a phosphate binder, sevelamer carbonate, inducing colitis in a 47-year-old male with insulin-dependent diabetes complicated by end-stage renal disease. He presented for recurrent abdominal pain with associated nausea and was found to have multiple circumferential lesions on computed tomography including distal ascending, transverse, and proximal descending colon. Colonoscopy demonstrated nearly obstructing lesions worrisome for colonic ischemia or inflammatory bowel disease. Pathological review of histology demonstrated ragged colonic mucosa with ulcerative debris and nonpolarizing crystalline material at the sites of ulceration, morphologically consistent with the phosphate binder, sevelamer carbonate. Sevelamer carbonate was discontinued, and the patient was transitioned to calcium carbonate with strict dietary restrictions. His symptoms improved with the cessation of sevelamer, and he was subsequently discharged home. He eventually underwent renal transplant without redevelopment of symptoms. Recognition of this underreported complication of sevelamer carbonate, phosphate binder, is of utmost importance in directing appropriate therapy with cessation of this medication in the setting of gastrointestinal complaints or more specifically enteritis and colitis. Clinicians providing care to end-stage renal patients taking either sevelamer and/or sodium polystyrene sulfonate should have increased awareness of the possible gastrointestinal side effects.
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PMID:Sevelamer Carbonate Crystal-Induced Colitis. 3277 46

Chemotherapeutic enteritis is a major dose-limiting adverse reaction to chemotherapy, with few effective drugs in clinic. Intestinal ischemic injury plays prominent role in chemotherapeutic enteritis clinically. However, mechanism is not clear. In this article, irinotecan (CPT-11) was used to establish chemotherapeutic enteritis mice model. Western blotting, gelatin zymography, immunohistochemistry (IHC), Laser Doppler flowmetry (LDF) were used to detect the pathogenesis of ischemia-hypoxia injury. CPT-11 increased levels of tissue factor (TF) both in the blood and in intestines, and decreased the intestinal blood flow in mice. Interestingly, the elevation of TF in the blood displayed "double-peak," which was consistent with the intestinal mucosal "double-strike" injury trend. Intestinal microthrombus and mixed thrombus formation were detectable in chemotherapeutic enteritis. Furthermore, ozone therapy relieved chemotherapeutic enteritis in mice. Ozone inhibited TF expression induced by CPT-11 via activating AMPK/SOCS3, and effectively ameliorated the intestinal mucosal injury in mice. Moreover, ozone autotransfusion therapy effectively attenuated chemotherapeutic enteritis and the blood hypercoagulability in patients. For the first time, we proposed that TF-induced thrombotic intestinal ischemic injury is a core trigger pathological mechanism of chemotherapeutic enteritis, and provided a new treatment strategy, ozone therapy, to suppress TF expression and treat chemotherapeutic enteritis.
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PMID:AMPK activation by ozone therapy inhibits tissue factor-triggered intestinal ischemia and ameliorates chemotherapeutic enteritis. 3277 74


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