Promoting mechanism by bile salt related to water absorption in drug rectal absorption.
The promoting mechanism by bile salts in rat rectal absorption of antipyrine was studied by the in situ recirculating perfusion. The significant correlation between rectal absorption clearance (CLAP) of antipyrine (AP) and apparent water influx (influx') was found in the control without promoters, indicating the existence of solvent drag in the AP rectal absorption. Sieving coefficient of AP (bAP), i.e. the slope of the regression line between CLAP and influx', was 0.6 approximately equal to that in small intestine reported previously. The relation between the promoting effects and solvent drag was further studied, resulting that both CLAP and influx' were significantly enhanced by sodium taurocholate (TC-Na), sodium glycocholate (GC-Na) and sodium cholate (C-Na). Accordingly the promoting effects of bile salts might be due to the increase in solvent drag. However TC-Na did not produce the significant change in bAP. From these results, the enhancing mechanism in the epithelial cell membrane transport was discussed.
D000818:Animals; D000983:Antipyrine / Q000378:metabolism; D001647:Bile Acids and Salts / Q000494:pharmacology*; D001834:Body Water / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013488:Suppositories; D013656:Taurocholic Acid / Q000494:pharmacology
D001647:Bile Acids and Salts; D013488:Suppositories; D013656:Taurocholic Acid; D000983:Antipyrine