Measurements of blood flow and xanthine oxidase activity during postischemic reperfusion of the large colon of ponies.
Abstract: To assess right colic artery blood flow and relevance of xanthine dehydrogenase/xanthine oxidase after experimentally induced strangulation obstruction and reperfusion of the colon, 5 ponies were subjected to 2.5 hours of complete ischemia of the left dorsal and ventral colons, allowed to recover from surgery, and monitored during a 48-hour reperfusion period. Five ponies were subjected to sham surgery and served as controls. All ponies had a Doppler ultrasound blood flow monitor implanted on the right colic artery near the pelvic flexure 10 to 14 days prior to the ischemic period. Colic artery blood flow was monitored prior to, during, and for 4 hours after surgery. Blood samples from the right colic artery and vein distal to the obstruction site were collected during surgery (prior to ischemia, after 1 and 2 hours of ischemia, and after 10 and 60 minutes of reperfusion) for determination of arterial and venous blood gas tensions and electrolytes. Prior to surgery, blood selenium and plasma vitamin E (alpha-tocopherol) concentrations and blood glutathione peroxidase (GPX) activity were determined to assess the status of endogenous antioxidants. Combined xanthine dehydrogenase (XDH) plus xanthine oxidase (XO) activity, and XO activity alone (nanomoles per minute per gram of tissue) were determined, using a dual-spectrophotometric technique. Xanthine dehydrogenase and oxidase activities were determined prior to ischemia, after 1 and 2 hours of ischemia, and at 1 and 48 hours after reperfusion. Median blood flow in the experimental and control groups (156 ml/min and 110 ml/min, respectively) was not statistically different before surgery, and was significantly (P < 0.02) lower in the experimental (4 ml/min) vs the control group (72.5 ml/min) during the ischemic period. Experimental ponies had significantly (P < 0.03) lower right colic artery blood flow during the 4 hours immediately after recovery from anesthesia. Significant difference was not observed in right colonic venous bicarbonate concentration between groups at any time. Median right colonic venous PCO2, pH, and standard base excess were different (P < 0.001) between groups during the ischemic period only. Median venous oxygen saturation and median venous PO2 were significantly (P < 0.001) lower in the experimental ponies at the end of 2 hours of ischemia, but were significantly (P < 0.05) increased during the reperfusion phase. Median venous potassium concentration was significantly (P < 0.01) higher in experimental ponies during the ischemic and reperfusion phases. Vitamin E and GPX values were within normal limits for all ponies.(ABSTRACT TRUNCATED AT 400 WORDS)
Publication Date: 1994-08-01 PubMed ID: 7978659
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The study involves an experiment on five ponies where their colonic blood flow and xanthine oxidase activity were measured during a specifically induced colon obstruction and reperfusion period. The findings provide important insights into arterial blood flow and the role of specific enzymes during ischemia and reperfusion.
Research Methodology
- The experiment was conducted on five ponies who underwent a controlled colon obstruction for 2.5 hours which was followed by a recovery period and subsequently a 48-hour reperfusion monitor.
- Five additional ponies experienced a mock surgery and served as the control group.
- All ponies had a Doppler ultrasound blood flow monitor implanted on the right colic artery close to the pelvic flexure around two weeks ahead of the obstruction
- Colic artery blood flow monitoring was undertaken before, during, and up to four hours following surgery.
- Several blood samples from various locations and timings were collected for measurement of arterial and venous blood gas tensions and electrolytes.
- Using a dual-spectrophotometric method, xanthine dehydrogenase/xanthine oxidase activities were measured at different intervals throughout the experiment.
- Average blood flow was measured for both groups at different times and was compared.
Key Findings
- The study found that before surgery, the median blood flow of the experimental and control groups showed no significant difference.
- During the ischemia period, the experimental group registered a significantly lower blood flow in comparison to the control group.
- Differences were also discovered in the right colic artery blood flow in the experimental group during the four-hour recovery from anesthesia.
- Contrast in terms of right colonic venous bicarbonate concentration between the groups was not observed at any point in time.
- During ischemia, there were notable differences in median right colonic venous PCO2, pH, and standard base excess.
- For the experimental group, median venous oxygen saturation and median venous PO2 dipped significantly towards the end of the ischemia period; however, they rose notably during reperfusion.
- The experimental group also recorded a higher median venous potassium concentration during the ischemia and reperfusion phases.
- Vitamin E and GPX levels were found to be within normal range for all ponies.
Conclusion
The study includes observations of the changes in blood flow and reactions of specific enzymes given a particular condition of induced colon obstruction and subsequent reperfusion in ponies. These research findings can provide valuable insights into further study of digestive health in equine species and possible implications to human health.
Cite This Article
APA
Wilkins PA, Ducharme NG, Lowe JE, Schwark WS, Meschter C, Erb HN.
(1994).
Measurements of blood flow and xanthine oxidase activity during postischemic reperfusion of the large colon of ponies.
Am J Vet Res, 55(8), 1168-1177.
Publication
Researcher Affiliations
- Department of Clinical Sciences, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
MeSH Terms
- Animals
- Antioxidants / metabolism
- Blood Flow Velocity
- Colic / enzymology
- Colic / physiopathology
- Colic / veterinary
- Colon / blood supply
- Colon / pathology
- Disease Models, Animal
- Electrolytes / blood
- Free Radicals
- Horse Diseases / enzymology
- Horse Diseases / pathology
- Horse Diseases / physiopathology
- Horses
- Hydrogen-Ion Concentration
- Intestinal Obstruction / enzymology
- Intestinal Obstruction / physiopathology
- Intestinal Obstruction / veterinary
- Oxygen / blood
- Reperfusion Injury / enzymology
- Reperfusion Injury / physiopathology
- Reperfusion Injury / veterinary
- Vascular Resistance
- Xanthine Oxidase / metabolism
Citations
This article has been cited 3 times.- Faleiros RR, Macoris DG, Alves GE, Souza DG, Teixeira MM, Moore RM. Local and remote lesions in horses subjected to small colon distension and decompression.. Can J Vet Res 2008 Jan;72(1):68-76.
- Mirza MH, Seahorn TL, Oliver JL, Hosgood G, Moore RM. Detection and comparison of nitric oxide in clinically healthy horses and those with naturally acquired strangulating large colon volvulus.. Can J Vet Res 2005 Apr;69(2):106-15.
- Mirza MH, Oliver JL, Seahorn TL, Hosgood G, Moore RM. Detection and comparison of nitric oxide in clinically normal horses and those with naturally acquired small intestinal strangulation obstruction.. Can J Vet Res 1999 Oct;63(4):230-40.
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