Effects of small bowel exclusion on intestinal myoelectrical activity pattern: comparison between innervated and denervated (transplanted) Thiry-Vella loops in rats.
Small bowel transplantation (SBT) leads to several changes in normal intestinal physiology with special reference to lymphatic disruption and graft denervation. Intestinal myoelectrical activity (MA) has been studied in different conditions, but little is known about MA in excluded bowel segments without the influence of nutrients. We performed this study to evaluate the effects of bowel exclusion on MA pattern. Fifteen Wistar rats were divided into two groups: five were used as donors and five as recipients for SBT; the remaining five underwent isolation of a jejunal segment as Thiry-Vella loop (TVL). On the 20th postoperative day, four bipolar electrodes were implanted in the small bowel of each rat: proximally and distally on the transplanted and the native intestine (SBT group); proximally and distally on the TVL and across the jejunal anastomosis (TVL group). On the 30th postoperative day, MA was recorded for 30 min after a 12 h fast. MA pattern was not altered by the exclusion of innervated jejunal segments (TVLs) with maintenance of high amplitude and migrating myoelectric complex (MMC) occurrence independent of MA in the continuity bowel. The characteristic regular spiking activity was not observed in transplanted grafts and MA analysis showed slow waves containing superimposed irregular spiking activity.
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Department of Experimental Surgery, Transplantation Laboratory, Federal University of San Paolo, Brazil. fefofofo@aol.com
Minioli
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Feo
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Forno
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Lopasso
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Larangeira
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Goldenberg
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Gomes
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Nigro
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D000818:Animals; D004567:Electrodes, Implanted; D007421:Intestine, Small / Q000502:physiology / Q000637:transplantation*; D007583:Jejunum / Q000294:innervation* / Q000601:surgery; D016065:Myoelectric Complex, Migrating / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar