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The present study aimed to evaluate the efficacy of mesenchymal stem cell (MSC) infusion, derived from adipose tissue, on reduction of local and remote tissue damage caused by the event of experimental intestinal I/R in New Zealand breed rabbits. For obtaining, characterization, and cultivation of MSC derived from adipose tissue (MSC-Adp), 3 juvenile animals (four months old) were used. The cells were considered to be viable for therapy after the fourth passage (in vitro phase). For the in vivo stage, 24 young adult animals (six months old) were used, weighing approximately 3.5 kg, in which were randomly divided into two groups, called: IR treated with MSC (I2H/R5H MSC 3D; I2H/R5H MSC 7D); IR treated with PBS (I2H/R5H PBS 3D; I2H/R5H PBS 7D). The animals were anesthetized and submitted to pre-retro-umbilical midline celiotomy. The extramural peri-intestinal marginal artery was located and clamped (predetermined and standardized region) with the aid of a vascular clip, promoting a 2 hour blood flow interruption. After this period, blood flow was reestablished, inhalatory anesthesia was suspended, and the animals awaken. After 5 hours of reperfusion, the treatments were performed by intravenous infusion according to the experimental groups. The animals were evaluated 72 hours and seven days after the treatment as for the macroscopic appearance (color and peristaltism) of the jejunal segment, and by histological evaluation of the ischemic segment for the presence or absence of destruction of the intestinal mucosa, edema, bleeding, dilation of lymph vessels, and presence of polymorphonuclear inflammatory cells, both in the mucosa and submucosa. The observed results revealed that the groups treated with MSC-Adp obtained smaller mucosal and submucosal lesions when compared to the groups treated with PBS. Also, MSC-Adp treated groups obtained controlled inflammatory response and higher mitotic rate, outcomes related to the therapeutic potential of MSC. Infusion of stem cells attenuated the lesions caused by intestinal I/R in both MSC groups when compared to the group treated with PBS.

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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.