Use of an extracorporeal circuit to evaluate effects of ischemia and reperfusion of the equine large colon

Linda M. Van Hoogmoed Comparative Gastroenterology Laboratory, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by Linda M. Van Hoogmoed in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Jack R. Snyder Comparative Gastroenterology Laboratory, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by Jack R. Snyder in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Jorge E. Nieto Comparative Gastroenterology Laboratory, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by Jorge E. Nieto in
Current site
Google Scholar
PubMed
Close
 MVZ
,
Nicholas J. Vatistas Comparative Gastroenterology Laboratory, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by Nicholas J. Vatistas in
Current site
Google Scholar
PubMed
Close
 BcVS, PhD
, and
Faye A. Harmon Comparative Gastroenterology Laboratory, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by Faye A. Harmon in
Current site
Google Scholar
PubMed
Close

Click on author name to view affiliation information

Abstract

Objective—To determine efficacy of an extracorporeal circuit to maintain a segment of equine large colon for 3.5 hours and to evaluate the effect of low arterial flow on histologic and metabolic variables.

Sample Population—Segments of large colon from 15 healthy adult horses.

Procedure—The pelvic flexure was surgically removed and maintained in an isolated circuit. In the control group, tissue was evaluated for 3.5 hours, whereas in the low-flow group, arterial flow was reduced to 20% of baseline for 40 minutes followed by 2 hours of reperfusion. Various metabolic and hemodynamic variables were evaluated at 30-minute intervals. Effects of nitric oxide (NO) and L-N-nitro-arginine- methyl-ester (L-NAME) on contractile activity were determined, and histomorphologic evaluation was performed at the completion of the study.

Results—Low-flow ischemia with reperfusion caused significant histomorphologic differences, compared with the control group. In the low-flow group, significant differences included reduction in PaCO2, reduction in bicarbonate concentrations, increase in PaO2, and an increase in base deficit in arterial and venous blood samples. Other significant differences included increases in PCV, protein concentration, total WBC count, and albumin clearance for the low-flow group. Differences were not detected in inhibitory activity of the low-flow group relative to the control tissue with or without addition of NO and L-NAME.

Conclusion—The extracorporeal circuit maintained a segment of equine intestine for 3.5 hours and can be used to simulate ischemic injury. The extracorporeal circuit provides the potential to investigate pharmaceutic agents that can minimize intestinal injury. (Am J Vet Res 2000;61:1042–1051)

Abstract

Objective—To determine efficacy of an extracorporeal circuit to maintain a segment of equine large colon for 3.5 hours and to evaluate the effect of low arterial flow on histologic and metabolic variables.

Sample Population—Segments of large colon from 15 healthy adult horses.

Procedure—The pelvic flexure was surgically removed and maintained in an isolated circuit. In the control group, tissue was evaluated for 3.5 hours, whereas in the low-flow group, arterial flow was reduced to 20% of baseline for 40 minutes followed by 2 hours of reperfusion. Various metabolic and hemodynamic variables were evaluated at 30-minute intervals. Effects of nitric oxide (NO) and L-N-nitro-arginine- methyl-ester (L-NAME) on contractile activity were determined, and histomorphologic evaluation was performed at the completion of the study.

Results—Low-flow ischemia with reperfusion caused significant histomorphologic differences, compared with the control group. In the low-flow group, significant differences included reduction in PaCO2, reduction in bicarbonate concentrations, increase in PaO2, and an increase in base deficit in arterial and venous blood samples. Other significant differences included increases in PCV, protein concentration, total WBC count, and albumin clearance for the low-flow group. Differences were not detected in inhibitory activity of the low-flow group relative to the control tissue with or without addition of NO and L-NAME.

Conclusion—The extracorporeal circuit maintained a segment of equine intestine for 3.5 hours and can be used to simulate ischemic injury. The extracorporeal circuit provides the potential to investigate pharmaceutic agents that can minimize intestinal injury. (Am J Vet Res 2000;61:1042–1051)

All Time Past Year Past 30 Days
Abstract Views 20 0 0
Full Text Views 216 109 19
PDF Downloads 59 39 8
Advertisement