The effect of dinoprost on transport of water and imipramine through rat small intestinal membranes.
The relation between transmucosal fluid movement and its effect on absorption and exsorption of imipramine was studied with the in-situ single-pass perfusion technique in rats. Dinoprost (prostaglandin F2 alpha, PGF2 alpha) caused a dose-related inhibition of both absorption and secretion of water across the intestinal membrane. When PGF2 alpha was infused at a rate of 5 mumols kg-1 h-1, the absorption rate of water decreased from 51.7 to 21.5 mL h-1 and the secretion rate decreased from 48.9 to 26.8 mL h-1. Net water flux changed from net water absorption (0.9 mL h-1) to net water secretion (5.33 mL h-1) by infusion of PGF2 alpha. However, absorption and exsorption of imipramine were little affected by infusion of PGF2 alpha. The absorption rates of imipramine were 3.03 and 2.36 mg h-1 in the absence and presence of PGF2 alpha, respectively. Furthermore, the average amounts of imipramine exsorbed into the intestinal lumen in 2 h were 7.82 and 8.10% in the absence and presence of PGF2 alpha, respectively. Infusion of PGF2 alpha also enhanced motility of the small intestine compared with the control. From these results, it appears that PGF2 alpha has no effect on the absorption and exsorption of imipramine across the intestinal membrane although it is reasonable to use PGF2 alpha in the case of patients with overdoses of drugs which decrease gastrointestinal motility.
Department of Pharmacy, Kumamoto University Hospital, Japan.
K
K
Arimori
M
M
Deshimaru
M
M
Nakano
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001834:Body Water / Q000378:metabolism*; D015237:Dinoprost / Q000494:pharmacology*; D062787:Drug Overdose; D005769:Gastrointestinal Motility / Q000187:drug effects; D007099:Imipramine / Q000493:pharmacokinetics*; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D015237:Dinoprost; D007099:Imipramine