title: Oxalate and sucralose absorption in idiopathic calcium oxalate stone formers.
abstract: OBJECTIVE
  To better understand intestinal oxalate transport by correlating oxalate and sucralose absorption in idiopathic calcium oxalate stone formers. Oxalate has been hypothesized to undergo absorption in the large and small intestine by both paracellular and transepithelial transport. Sucralose is a chlorinated sugar that is absorbed by paracellular mechanisms.
  
  
  METHODS
  Idiopathic calcium oxalate stone formers were recruited to provide urine specimens on both a self-selected diet and after a meal containing 90 mg of (13)C(2-)oxalate and 5 g of sucralose, and a stool sample for determination of Oxalobacter formigenes colonization. The 24-hour urine collections were fractionated into the first 6 hours and the subsequent 18 hours. Sucralose and oxalate excretion were measured during these periods and used to estimate absorption.
  
  
  RESULTS
  Thirty-eight subjects were evaluated. The majority of both the (13)C(2-)oxalate and sucralose absorption occurred within the 0-6-hour collection. The (13)C(2-)oxalate and sucralose absorptions were significantly correlated at the 0-6 hour, the 6-24 hour, and the total 24-hour time periods (P <.04). All 5 oxalate hyperabsorbers(>15% absorption) also absorbed significantly more sucralose during the 0-6 hour and whole 24-hour time points (P <.04). Oxalobacter formigenes colonization did not significantly alter oxalate absorption.
  
  
  CONCLUSIONS
  The results suggest that most oxalate is absorbed in the proximal portion of the gastrointestinal tract and that paracellular transport is involved. Augmented paracellular transport, as evidenced by increased sucralose absorption, may also influence oxalate absorption.
authors.affiliation: Department of Urology, Wake Forest University Medical Center, Winston-Salem, NC 27157, USA.
authors.forename: John
authors.initials: J
authors.lastname: Knight
authors.forename: Juquan
authors.initials: J
authors.lastname: Jiang
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Wood
authors.forename: Ross P
authors.initials: RP
authors.lastname: Holmes
authors.forename: Dean G
authors.initials: DG
authors.lastname: Assimos
mesh_terms: D002129:Calcium Oxalate / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D008875:Middle Aged; D010070:Oxalates / Q000493:pharmacokinetics*; D013395:Sucrose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D013549:Sweetening Agents / Q000493:pharmacokinetics*; D014545:Urinary Calculi / Q000378:metabolism*
chemical_list: D010070:Oxalates; D013549:Sweetening Agents; D002129:Calcium Oxalate; D013395:Sucrose; C026285:trichlorosucrose