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
Animals—84 horses that underwent small intestinal
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
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)
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.
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
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)