ABSORPTION OF A VASOPRESSIN ANALOG, 1-DEAMINO-8-D-ARGININE-VASOPRESSIN (DDAVP), IN A HUMAN INTESTINAL EPITHELIAL-CELL LINE, CACO-2

The intestinal absorption of the metabolically stable vasopressin analogue dDAVP was studied in human intestinal epithelial (CaCO-2) cells grown on permeable supports. The parent peptide arginine-vasopressin (AVP) was used as a control peptide. Both peptides displayed linear kinetics and were absorbed at very slow rates across CaCO-2 monolayers. The apparent permeability coefficients were in the range of 4-14 × 10-8 cm/s. No degradation of dDAVP and AVP was observed during the incubation period. The absorption of dDAVP was concentration independent, indicating that the transport was mediated by a passive permeation. The low permeability coefficients indicate that the absorption rate across CaCO-2 monolayers is similar to that of colonic epithelium in vivo. © 1990.