Abstract
The effect of membrane surface potential of the apical side on the intracellular uptake of ionic compounds was investigated using the human colon adenocarcinoma cell line (Caco-2). The transepithelial transport of indolepropionic acid and tryptamine was consistent with the uptake behavior shown by rat intestinal brush-border membrane (BBM) vesicles. Imipramine, which diminished the negative charge of the membrane surface (for both Caco-2 and BBM), acted to increase the uptake of the anionic compounds, indolepropionic acid and ceftibuten, and to decrease that of tryptamine (cationic compound) by both the Caco-2 monolayer and the intestinal BBM vesicles at a pH of 7.5. These results suggest that the effects of membrane surface potential on the permeability of ionic compounds were detectable on the Caco-2 cell line as well as the BBM vesicles. On the other hand, the inhibition of H(+)-linked transport and the stimulation of the surface charge-regulated uptake of ceftibuten have occurred simultaneously on the Caco-2 cell line in the presence of imipramine. It seems that the membrane surface charge (negative) plays an important role in the transport process of ionic compounds across the intestinal epithelium.
Sign-in/Register to access full text options 
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 callDisclaimer: 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.
