Establishment of an experimental model of small intestinal ischemia and reperfusion injuries in New Zealand rabbits

Abstract

The present study aimed to establish a methodology capable to cause intestinal ischemia and reperfusion injuries, to perform clamping of the jejunal segment of the extramural peri-intestinal marginal artery branch. For this, 37, 10-week-old male New Zealand breed rabbits were used. One rabbit was used to establish the anatomic references for the procedure and was not part of the six experimental groups; the rest were allocated into six experimental groups: Sham group, negative control, subjected only to midline celiotomy; group I1H undergoing vascular occlusion for an hour; group I2H submitted to vascular occlusion for two hours; group I1H/R2H undergoing vascular occlusion for one hour followed by two hours of reperfusion; group I2H/R1H undergoing vascular occlusion for two hours, followed by reperfusion for one hour, and group I2H/R5H undergoing vascular occlusion for two hours followed by reperfusion for five hours. The rabbits were evaluated for the macroscopic aspects (color and peristalsis) of the jejunal segment, as well as the histological aspect, checking for presence or absence of mucosal destruction, edema, hemorrhaging, lymphatic vessel dilatation, and the presence of polymorphonuclear cells. It was observed that the macroscopic and histopathological lesions accentuated in larger employed ischemia and reperfusion times. Rabbits subjected to ischemia for two hours followed by reperfusion for five hours (I2H/R5H) made up the experimental group which was easily reproducible and showed moderate intestinal injury, different from the other groups.

Experimental Animal Models for Studying Intestinal Obstruction

“…Hatton et al [24] reported that from 1966 to 2014, rodents consisted up to 90% of animal species in biomedical research, with rabbits, pigs, dogs, monkeys, and guinea pigs accounting for the rest 10%. The same trend toward rodents is underlined by Oliveira et al [25], reporting that 73% of ischemia-reperfusion models utilize rodents as animal species, followed by pigs at 9%, dogs at 8%, and felines at 6%. Ewes' models are mostly cited in the literature in the mid-twentieth century, an era when metabolic mechanisms hindered behind electrolyte changes and clinical outcomes were under the microscope, as well as research on the field of bowel response Experimental Animal Models for Studying Intestinal Obstruction DOI: http://dx.doi.org/10.5772/intechopen.115008 to trauma and pain [26][27][28].…”

“…This model can be performed both in large animals and rodents, providing multiple treatment groups in a single animal as multiple loops can undergo varying durations of ischemia, with or without reperfusion, allowing for adjustment of the degree of injury. Oliveira et al [25] in order to precisely locate the marginal artery branch, injected blue liquid dye in the jugular vein and carotid artery of a "pilot" rabbit before the experiment and managed to establish consistency of the occlusion site. Matsuo et al [104] placed an acrylic ring around a balloon and a loop of the distal ileum of rats.…”