ABSTRACT
The compensatory hypertrophy that develops after massive enterectomy is rarely adequate to prevent the development of short bowel syndrome. Trophic hormones such as epidermal growth factor (EGF) and neurotensin (NT) may be useful in improving and accelerating this adaptive response. This study delineates the effects of NT and EGF on remnant small bowel at the microvillus cellular level, which is the prime determinant of surface area. New Zealand white rabbits (2 kg) underwent midgut transection (sham) or 70% jejunoileal resection. Alzet pumps containing saline solution (control), EGF (1.5 microg /kg/hr), or NT (900 microg/kg/day) were implanted in resected animals after which they underwent 1 week of infusion. A second group of EGF animals was killed 2 weeks after infusion completion to assess delayed effects (EGF-delayed). Proximal jejunum was fixed for light and electron microscopy; villus and microvillus parameters were read in a blinded fashion. EGF (2.17+/-0.05 microm), EGF-delayed (2.26+/-1.5 microm, and NT (1.96+/-0.02 microm) animals had significantly increased microvillus heights compared to the control group (1.49+/-0.04 microm). Calculated brush-border surface areas were increased in a similar fashion. EGF and NT failed to elicit increases in jejunal gross villus heights. EGF and NT induce enterocyte microvillus hypertrophy and increase absorptive surface area in remnant bowel after massive enterectomy. In addition, the trophic effects of EGF persist after cessation of infusion. These peptides may be useful in accelerating small bowel adaption and preventing the development of short gut syndrome.
Subject(s)
Epidermal Growth Factor/physiology , Intestinal Mucosa/pathology , Intestinal Mucosa/ultrastructure , Intestines/surgery , Neurotensin/physiology , Animals , Male , Microvilli/pathology , RabbitsABSTRACT
BACKGROUND: Octreotide (SMS) is a somatostatin analogue utilized in patients with short bowel syndrome (SBS) to decrease output. It may inhibit small bowel adaptation by blocking the secretion of trophic hormones such as epidermal growth factor (EGF). This study delineates the effects of SMS and EGF on nutrient transport in SBS. METHODS: One week after 70% jejunoileal resection, 20 New Zealand White rabbits (2 kg) received subcutaneous infusions of saline or EGF (1.5 micrograms/kg/hr) and injections of saline or SMS s.q.b.i.d. The study groups were EGF/saline, saline/saline, saline/SMS, and EGF/SMS. After 7 days of infusion, intestinal brush border membrane vesicles were prepared and nutrient transport measured. RESULTS: SMS reduced active nutrient transport. Kinetics confirmed this was secondary to a reduction in functional carriers in the brush border membrane, without a change in carrier affinity. The coinfusion of EGF ameliorated this effect. On an individual basis, EGF alone did not significantly increase nutrient transport, but when taken as a group, nutrients transport was upregulated 26%. CONCLUSIONS: SMS is detrimental to small bowel adaptation. EGF reverses this effect and may benefit patients with SBS who require SMS to control high intestinal output.
Subject(s)
Amino Acids/metabolism , Epidermal Growth Factor/pharmacology , Gastrointestinal Agents/pharmacology , Glucose/metabolism , Intestine, Small/metabolism , Octreotide/pharmacology , Animals , Biological Transport, Active/drug effects , Down-Regulation , Epidermal Growth Factor/blood , Ileum/surgery , In Vitro Techniques , Jejunum/surgery , Male , Microvilli/metabolism , Rabbits , Short Bowel Syndrome/metabolismABSTRACT
BACKGROUND: Studies in animals with short bowel syndrome (SBS) suggest that up-regulation of nutrient transporter activity occurs as an adaptive response to the loss of absorptive area. It is unclear, however, whether nutrient transport is altered at the cell membrane in SBS. The purpose of this study is to clarify amino acid and glucose transport in small intestinal luminal mucosa after 70% small bowel resection in rabbits. METHODS: New Zealand white rabbits underwent 70% jejunoileal resection (n = 27) or a sham operation (n = 19). Brush border membrane vesicles were prepared from small intestinal mucosa at 1 week, 1 month, and 3 months by magnesium aggregation-differential centrifugation. Transport of L-glutamine, L-alanine, L-leucine, L-arginine, and D-glucose was assayed by a rapid mixing-filtration technique. RESULTS: We observed no difference in uptake of all amino acids and glucose at 1 week. The uptake of amino acids and glucose was decreased by 20% to 80% in animals with SBS at 1 month. By 3 months all uptake values except that of glucose returned to normal. Kinetic studies of the system B transporter for glutamine indicate that the decrease in uptake at 1 month was caused by a reduction in the Vmax (1575 +/- 146 versus 2366 +/- 235, p < 0.05) consistent with a decrease in the number of functional carriers on the brush border membrane. CONCLUSIONS: In addition to the anatomic loss of absorptive area after massive bowel resection, alterations in enterocyte transport function may be responsible for malabsorption in patients with SBS.
Subject(s)
Amino Acids/metabolism , Glucose/metabolism , Intestinal Mucosa/metabolism , Intestine, Small/surgery , Animals , Biological Transport , Intestinal Mucosa/ultrastructure , Male , Microvilli/metabolism , RabbitsABSTRACT
BACKGROUND: Young women with nondescript abdominal pain can be difficult to diagnose. Although extrapelvic endometriosis is infrequent, we have treated 7 patients over the past 3 years with endometriosis in the abdominal wall, inguinal canal, or surgical incisions as the etiology of their symptoms. PATIENTS AND METHODS: We reviewed the medical records of patients whose final pathology report confirmed a diagnosis of extrapelvic endometriosis. Seven women who were treated at the University of Rochester Strong Memorial Hospital from May 1, 1991 through April 30, 1994 were identified. RESULTS: All patients were premenopausal with no history of pelvic endometriosis. In 4 patients, symptoms were cyclical. Surgical excision was initially curative in 5 patients. Two women required reexcision. The diagnosis of endometriosis was established at exploration by gross appearance and by frozen section. CONCLUSIONS: Endometriosis should be included in the differential diagnosis of a symptomatic mass in a celiotomy scar, the abdominal wall, or the inguinal canal. Principles of management include obtaining an accurate diagnosis and performing an adequate excision to prevent recurrence.