Effect of caffeine, theophylline and nicotine on D-glucose and folate transport in rat jejunal brush border membrane vesicles.
1. Nicotine at 10 mM, but not caffeine or theophylline, reduced by 20% the overshoot of the Na+-dependent D-glucose transport in rat jejunal brush border membrane vesicles. 2. Since nicotine did not affect the transport of Na+, its inhibition on Na+-dependent D-glucose transport must be due to a direct effect upon the D-glucose transport system. 3. Folate transport in these membrane vesicles was found to a be a free diffusion process at pH 7.4. 4. Neither caffeine, theophylline nor nicotine has any effect on folate transport.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D005492:Folic Acid / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D007583:Jejunum / Q000378:metabolism; D008297:Male; D008871:Microvilli / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000494:pharmacology*
D002110:Caffeine; D009538:Nicotine; D005492:Folic Acid; D013806:Theophylline; D005947:Glucose