PURPOSE: To compare the permeation characteristics of amide bond-containing HIV-1 protease inhibitors and their pyrrolinone-containing counterparts across Caco-2 cell monolayers, a model of the intestinal mucosa. METHODS: Transepithelial transport and cellular uptake of three pairs of amide bond-containing and pyrrolinone-based peptidomimetics were assessed in the presence and absence of cyclosporin A using the Caco-2 cell culture model. The potential of the peptidomimetics to interact with biological membranes was estimated by IAM chromatography. RESULTS: In the absence of cyclosporin A, apical (AP) to basolateral (BL) flux of all compounds studied was less than the flux determined in the opposite direction (i.e., BL-to-AP). The ratio of the apparent permeability coefficients (Papp) calculated for the BL-to-AP and AP-to-BL transport (P(BL-->AP)/P(AP-->BL)) varied between 1.7 and 36.2. When individual pairs were ompared, P(BL-->AP)/P(AP-BL) ratios of the pyrrolinone-containing compounds were 1.5 to 11.5 times greater than those determined for the amide bond-containing analogs. Addition of 25 microM cyclosporin A to the transport buffer reduced the P(BL-->AP)/P(AP-->BL) ratios for all protease inhibitors to a value close to unity. Under these conditions, the amide bond-containing peptidomimetics were at least 1.6 to 2.8 times more able to permeate Caco-2 cell monolayers than were the pyrrolinone-containing compounds. The intrinsic uptake characteristics into Caco-2 cells determined in the presence of 25 microM cyclosporin A were slightly greater for the amide bond-containing protease inhibitors than for the pyrrolinone-containing analogs. These uptake results are consistent with the transepithelial transport results determined across this in vitro model of the intestinal mucosa. CONCLUSIONS: The amide bond-containing and pyrrolinone-based peptidomimetics are substrates for apically polarized efflux systems present in Caco-2 cell monolayers. The intrinsic permeabilities of the amide bond-containing protease inhibitors are slightly greater than the intrinsic permeabilities of the pyrrolinone-based analogs through Caco-2 cell monolayers.
PURPOSE: To compare the permeation characteristics of amide bond-containing HIV-1 protease inhibitors and their pyrrolinone-containing counterparts across Caco-2 cell monolayers, a model of the intestinal mucosa. METHODS: Transepithelial transport and cellular uptake of three pairs of amide bond-containing and pyrrolinone-based peptidomimetics were assessed in the presence and absence of cyclosporin A using the Caco-2 cell culture model. The potential of the peptidomimetics to interact with biological membranes was estimated by IAM chromatography. RESULTS: In the absence of cyclosporin A, apical (AP) to basolateral (BL) flux of all compounds studied was less than the flux determined in the opposite direction (i.e., BL-to-AP). The ratio of the apparent permeability coefficients (Papp) calculated for the BL-to-AP and AP-to-BL transport (P(BL-->AP)/P(AP-->BL)) varied between 1.7 and 36.2. When individual pairs were ompared, P(BL-->AP)/P(AP-BL) ratios of the pyrrolinone-containing compounds were 1.5 to 11.5 times greater than those determined for the amide bond-containing analogs. Addition of 25 microM cyclosporin A to the transport buffer reduced the P(BL-->AP)/P(AP-->BL) ratios for all protease inhibitors to a value close to unity. Under these conditions, the amide bond-containing peptidomimetics were at least 1.6 to 2.8 times more able to permeate Caco-2 cell monolayers than were the pyrrolinone-containing compounds. The intrinsic uptake characteristics into Caco-2 cells determined in the presence of 25 microM cyclosporin A were slightly greater for the amide bond-containing protease inhibitors than for the pyrrolinone-containing analogs. These uptake results are consistent with the transepithelial transport results determined across this in vitro model of the intestinal mucosa. CONCLUSIONS: The amide bond-containing and pyrrolinone-based peptidomimetics are substrates for apically polarized efflux systems present in Caco-2 cell monolayers. The intrinsic permeabilities of the amide bond-containing protease inhibitors are slightly greater than the intrinsic permeabilities of the pyrrolinone-based analogs through Caco-2 cell monolayers.
Authors: A B Smith; R Hirschmann; A Pasternak; W Yao; P A Sprengeler; M K Holloway; L C Kuo; Z Chen; P L Darke; W A Schleif Journal: J Med Chem Date: 1997-08-01 Impact factor: 7.446
Authors: A B Smith; R Hirschmann; A Pasternak; R Akaishi; M C Guzman; D R Jones; T P Keenan; P A Sprengeler; P L Darke; E A Emini Journal: J Med Chem Date: 1994-01-21 Impact factor: 7.446
Authors: M Miller; J Schneider; B K Sathyanarayana; M V Toth; G R Marshall; L Clawson; L Selk; S B Kent; A Wlodawer Journal: Science Date: 1989-12-01 Impact factor: 47.728