Polymeric dyes: useful nonabsorbable reference markers for intestinal perfusion studies in animals.
The properties of two polymeric dyes were examined to determine their suitability as nonabsorbable reference markers for intestinal perfusion studies. The first dye was a violet anthroquinone dye, R-478, named polyporphyre; the second was a blue anthroquinone dye, R-411, named polycyanine. The dyes could be determined spectrophotometrically over a concentration range of 0.03-5 microM (1-200 micrograms/mL) and had no appreciable osmotic effect. They were light stable and their absorption spectra did not change in solution over a pH range of 1-11. The dyes had a molecular weight of approximately 40,000 by gel permeation chromatography; they did not appear to have hydrophobic binding sites because they did not bind added dihydroxy bile acid or fatty acid anions. Determination of the dyes was not influenced by the presence of bilirubin when the latter was present at concentrations reported to occur in small intestinal content during digestion. The dyes did not interfere with an endpoint enzymatic determination of bile acids. The dyes caused little quenching of 3H- or 14C-radioactivity in a toluene-based liquid scintillation cocktail. Dyes were easily removed from aqueous solution by passage over a large-pore anion exchange column or by a BaCl2:ZnSO4 protein precipitation procedure. When tested in a rat jejunal perfusion model, changes in dye concentration evoked by hypotonic or hypertonic perfusates were identical to those of polyethylene glycol 4000, a commonly used reference marker. The dyes did not influence the rate of glucose absorption and did not bind to mucus.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D001647:Bile Acids and Salts; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004396:Coloring Agents; D007422:Intestines / Q000098:blood supply*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow
D001647:Bile Acids and Salts; D004396:Coloring Agents