Comparison of 5-aminosalicylic acid and N-acetylaminosalicylic acid uptake by the isolated human colonic epithelial cell.
Isolated human colonic epithelial cell suspensions were incubated with either 0.1 mM 5-aminosalicylic acid (5-ASA) or 0.1 mM acetylaminosalicylic acid (Ac-ASA) for up to two hours. Intra- and extracellular 5-ASA and Ac-ASA were measured by high performance liquid chromatography. Mean 5-ASA uptake in one hour was 160.5 nmol/g dry weight, compared with an Ac-ASA uptake of only 5.75 nmol/g dry weight. No unchanged 5-ASA was detected inside the cell. Repeated washing had no effect on the intracellular Ac-ASA concentration. This discrepancy in drug uptake may explain why Ac-ASA seems to be ineffective when given to patients with ulcerative colitis.
Ireland
A
A
Gastroenterology Unit, Radcliffe Infirmary, Oxford.
Priddle
J D
JD
Jewell
D P
DP
D000636:Aminosalicylic Acids / Q000378:metabolism*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003106:Colon / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D019804:Mesalamine; D007507:Therapeutic Irrigation; D013997:Time Factors
D000636:Aminosalicylic Acids; D019804:Mesalamine; C028836:N-acetyl-5-aminosalicylic acid