Abstract

Absorption and metabolic characteristics of p-aminobenzoic acid (PABA) and m-aminobenzoic acid (MABA) from the rat small intestine were examined by means of in situ recirculation and in vitro everted sac experiments. p-Aminobenzoic acid was extremely rapidly absorbed from the rat small intestine, whereas the absorption of MABA, the m-isomer of PABA, was comparably slower. This finding was partly explained by the result that PABA is more lipophilic than MABA. The metabolite percentage of PABA was considerably greater than that of MABA in mucosal fluid, tissue, and serosal fluid. On the other hand, a concentration-dependent and a directional difference in the transfer rate of these drugs were observed in everted and noneverted sacs of rat small intestine. Furthermore, mucosal uptake of PABA or MABA was inhibited by 1 mM 2,4-dinitrophenol, 10 mM sodium azide, and pretreatment with HgCI2 (10 mM). These results indicate that MABA, as well as PABA, is transported through the intestine by a carrier-mediated transport system, and that the molecular structure of these drugs is important for their absorption and metabolic characteristics.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.