Effect of exploratory laparotomy on canine gastrointestinal motility and plasma ghrelin level and the prokinetic effect of erythromycin after operation

Abstract

Objective To study the effect of exploratory laparotomy on canine gastrointestinal motility and plasma ghrelin level,and to observe the prokinetic effect of erythromycin after operation.Methods Chronic experiment was carried out in 38 conscious Beagles.Strain gauges were implanted on antrum,duodenum,proximal jejunum,and distal colon to record gastrointestinal motility.Dogs were prepared with chronic gastric fistula in addition to a jugular vein cannulation.There were 4 groups:(1) Control group,no laparotomy,no erythromycin ; (2) Exploratory laparotomy group ; (3) Exploratory laparotomy + erythromycin ; (4) Exploratory laparotomy + saline.Results (1) Control group showed typical interdigestive migrating motor complex (MMC).(2) In the exploratomy laparotomy group,on the day of surgery,during recovery period from anesthetia,no MMC was recorded.The sum of contracting waves increased in antrum,duodenum,and jejunum but decreased in colon.The amplitude index significantly decreased (70.76 ± 9.36) ％ to (92.51 ± 13.17) ％ (all P ＜0.01).On postoperative day 1 to 5,there was no MMC in conscious dogs.The sum of contracting waves increased in antrum and colon,but decreased in duodenum and jejunum.The amplitude index significantly decreased (33.83 ± 5.16) ％ to(70.71 ± 8.5) ％ (all P＜0.01).In both sedative and conscious status,by postoperative day 6 to 7,gastrointestinal motility recovered to baseline.On the postoperative day 0 to 5 the mean plasma ghrelin levels decreased markedly compared with the control group(P＜ 0.01).By postoperative day 7,the ghrelin recovered to baseline.(3) In exploratory laparatory +erythromycin group,intravenous injection of erythromycin 2 mg/kg significantly increased the postoperative gastrointestinal motility and stimulated ghrelin release.Conclusions Gastrointestinal motility was significantly disturbed after exploratory laparatomy.The motility and plasma ghrelin concentration both decreased markedly.Erythromycin showed a positive prokinetic effect through release of endogenous ghrelin in the dog. Key words: Explorotory laparotomy; Gastrointestinal motility ; Ghrelin ; Erythromycin