Search Results

Abstract

Objective—To determine whether location and type of small intestinal anastomosis and other variables were associated with short- and long-term survival rates in horses undergoing stapled small intestinal anastomosis.

Design—Retrospective study.

Animals—84 horses that underwent small intestinal anastomosis.

Procedure—Medical records from 1988 to 1997 were examined for horses that underwent stapled small intestinal anastomosis. Horses were allotted into 4 groups: jejunojejunostomy (n = 27), jejunoileostomy (11), jejunoileocecostomy with small intestinal resection (20), and jejunoileocecostomy without small intestinal resection (26). Survival rates and other variables were determined.

Results—Horses that underwent jejunoileocecostomy without resection had a significantly higher survival rate at all intervals than did horses in the other 3 groups. At 180 and 365 days after surgery, horses that underwent jejunojejunostomy had a significantly lower survival rate than those that underwent jejunoileocecostomy with intestinal resection. Horses that underwent jejunoileocecostomy with intestinal resection had a significantly higher survival rate at 1 year, compared with the combined jejunojejunostomy and jejunoileostomy groups. Preoperative heart rate was inversely associated with survival rate. Overall survival rates at discharge and 1 year were 81 and 56%, respectively. For horses that underwent small intestinal resection, survival rates at discharge and 1 year were 65 and 47%, respectively.

Conclusions and Clinical Relevance—Horses that underwent anastomosis of the small intestine to the cecum without resection had the highest survival rate, compared with horses that required intestinal resection. In some instances, resection and anastomosis involving the cecum had better prognosis than resections involving 2 segments of the small intestine. (J Am Vet Med Assoc 2001;218:1603–1607)

Abstract

Objective—To determine whether inflammation of the jejunum of horses decreases the number of motilin receptors and amounts of motilin receptor mRNA and alters erythromycin lactobionate binding affinity to the motilin receptor in jejunal tissues.

Sample Population—Jejunal segments in 6 adult horses.

Procedure—Each horse was anesthetized, and a ventral median celiotomy was performed; 2 segments of jejunum underwent a sham operation, 2 segments underwent ischemic strangulation obstruction (ISO), and 2 segments underwent intraluminal distension (ILD). Treatments were maintained for 120 minutes. From each segment, full-thickness biopsy samples were collected and smooth-muscle homogenates were prepared. Affinity and distribution of motilin binding to these preparations were determined by use of iodine 125 (¹²⁵I)-labeled synthetic porcine motilin. Via displacement experiments, competition between ¹²⁵I-labeled motilin and erythromycin lactobionate for binding to motilin receptors in the different segments was investigated. A quantitative real-time PCR technique was used to assess motilin receptor mRNA content in the muscle preparations.

Results—Compared with the ISO or ILD segments, the number of motilin receptors was significantly higher in the sham-operated segments; ILD segments contained the lowest number of motilin receptors. The expression of motilin receptor mRNA was significantly decreased in ILD segments but not in ISO segments. Erythromycin lactobionate displacement of ¹²⁵I-labeled motilin from motilin receptors did not differ significantly among the jejunal segments.

Conclusions and Clinical Relevance—Results suggest that downregulation and decreased production of motilin receptors in inflamed jejunal tissue contribute to the altered prokinetic response to erythromycin in horses with gastrointestinal disease.

Abstract

Objective—To identify and characterize motilin receptors in equine duodenum, jejunum, cecum, and large colon and to determine whether erythromycin lactobionate competes with porcine motilin for binding to these receptors.

Sample Population—Specimens of various segments of the intestinal tracts of 4 adult horses euthanatized for reasons unrelated to gastrointestinal tract disease.

Procedure—Cellular membranes were prepared from smooth muscle tissues of the duodenum, jejunum, pelvic flexure, and cecum. Affinity and distribution of motilin binding on membrane preparations were determined by use of ¹²⁵I-labeled synthetic porcine motilin. Displacement studies were used to investigate competition between ¹²⁵I-labeled synthetic porcine motilin and erythromycin lactobionate for binding to motilin receptors in various segments of bowel.

Results—Affinity of ¹²⁵I-labeled synthetic porcine motilin for the equine motilin receptor was estimated to be 6.1nM. A significantly higher number of motilin receptors was found in the duodenum than in the pelvic flexure and cecum. The jejunum had a significantly higher number of motilin receptors than the cecum. Erythromycin lactobionate displacement of ¹²⁵I-labeled porcine motilin from the equine motilin receptor did not differ significantly among various segments of bowel.

Conclusions and Clinical Relevance—Motilin receptors were found in the duodenum, jejunum, pelvic flexure, and cecum of horses. The highest number of motilin receptors was in the duodenum, and it decreased in more distal segments of bowel. Erythromycin lactobionate competed with motilin binding in the equine gastrointestinal tract. This suggests that 1 of the prokinetic actions of erythromycin in horses is likely to be secondary to binding on motilin receptors. (Am J Vet Res 2002;63:1545–1550)