title: Sequential alterations in gut mucosal amino acid and glucose transport after 70% small bowel resection.
abstract: 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.
authors.affiliation: Department of Surgery, University of Rochester Medical Center, NY 14642-8410, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Sarac
authors.forename: A S
authors.initials: AS
authors.lastname: Seydel
authors.forename: C K
authors.initials: CK
authors.lastname: Ryan
authors.forename: P Q
authors.initials: PQ
authors.lastname: Bessey
authors.forename: J H
authors.initials: JH
authors.lastname: Miller
authors.forename: W W
authors.initials: WW
authors.lastname: Souba
authors.forename: H C
authors.initials: HC
authors.lastname: Sax
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D005947:Glucose / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000648:ultrastructure; D007421:Intestine, Small / Q000601:surgery*; D008297:Male; D008871:Microvilli / Q000378:metabolism; D011817:Rabbits
chemical_list: D000596:Amino Acids; D005947:Glucose