title: Validation of polyethylene glycol 3350 as a poorly absorbable marker for intestinal perfusion studies.
abstract: Polyethylene glycol (PEG) has been used as a poorly absorbable marker in intestinal perfusion studies, but there is controversy about the absorbability of PEG, particularly when glucose-sodium cotransport is occurring. Total intestinal perfusion studies were done in five normal humans using three solutions containing 1 g/liter PEG 3350 and designed to produce low rates of water absorption, high rates of water absorption, or high rates of glucose-sodium cotransport. Water absorption rates were calculated by traditional nonabsorbable marker equations and by a novel balance technique in which absorption was taken as the difference between the volumes of solution infused and recovered during steady-state conditions. Effluent PEG recovery was 99 +/- 4%, 109 +/- 2%, and 104 +/- 6% of the amount infused with each solution. Water absorption rates measured by use of PEG concentrations were similar to those calculated by the balance technique (r = 0.99). The complete recovery of PEG confirms the poor absorbability of PEG 3350, and the excellent agreement between techniques validates PEG as a poorly absorbed marker, even when glucose-sodium cotransport is occurring.
authors.affiliation: Department of Internal Medicine, Baylor University Medical Center, Dallas, Texas 75246, USA.
authors.forename: L R
authors.initials: LR
authors.lastname: Schiller
authors.forename: C A
authors.initials: CA
authors.lastname: Santa Ana
authors.forename: J
authors.initials: J
authors.lastname: Porter
authors.forename: J S
authors.initials: JS
authors.lastname: Fordtran
mesh_terms: D000328:Adult; D001692:Biological Transport; D005947:Glucose / Q000493:pharmacokinetics; D006801:Humans; D007038:Hypotonic Solutions / Q000493:pharmacokinetics; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D008353:Mannitol / Q000493:pharmacokinetics; D008875:Middle Aged; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000493:pharmacokinetics; D014867:Water / Q000378:metabolism
chemical_list: D007038:Hypotonic Solutions; D014867:Water; D008353:Mannitol; D011092:Polyethylene Glycols; D005947:Glucose