Cyclic adenosine-3',5'-monophosphate and folate transport in rat jejunum.
The intestinal transport of 5-methyltetrahydrofolate and pteroylmonoglutamate was examined in everted sacs of rat jejunum exposed to compounds which increase intracellular cyclic adenosine-3', 5'-monophosphate. Adenyl cyclase stimulators (hydrocortisone and prostaglandin), phosphodiesterase inhibitors (3-isobutyl-l-methylxanthine, aminophylline and papaverine), and dibutyryl adenosine-3',5'-cyclicmonophosphate added to the mucosal medium inhibit the mucosal-to-serosal transport of physiological concentrations of 5-methyltetrahydrofalate and pteroylmonoglutamate. Transport inhibition is correlated with the ability of these agents to increase cellular cyclic adenosine-3', 5'-monophosphate. The active, carrier-mediated transport system of folate compounds is highly sensitive to the increase in cyclic adenosine-3', 5'-monophosphate level, while the diffusion system is insensitive. These data indicate that the active transport system of folates is modulated by cellular cyclic adenosine-3', 5'-monophosphate.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000628:Aminophylline / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active; D000242:Cyclic AMP / Q000378:metabolism*; D005492:Folic Acid / Q000378:metabolism*; D006854:Hydrocortisone / Q000494:pharmacology; D007583:Jejunum / Q000378:metabolism*; D008297:Male; D010208:Papaverine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000628:Aminophylline; D005492:Folic Acid; D010208:Papaverine; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine; D006854:Hydrocortisone