Schistosoma mansoni: serotonin uptake and its drug inhibition.
5-Hydroxytryptamine (serotonin) uptake by male and female Schistosoma mansoni was studied in vitro. Initial uptake was determined during the first 2 min of incubation with the indoleamine. There were two types of uptake: a saturable component that is apparent at low concentrations of serotonin, and a passive component that predominates at high concentrations. Female S. mansoni take up more 5-hydroxytryptamine per milligram protein than do the males. Studies on the distribution of 5-hydroxytryptamine taken up by the parasites show that a large proportion of the indoleamine is in the tegument. The female tegument had a greater proportion of the 5-hydroxytryptamine taken up than did the male tegument. The evidence indicated that 5-hydroxytryptamine associated with tegument represented the passive uptake while uptake in the main parasite body was both active and passive. Compounds that were shown to inhibit 5-hydroxytryptamine uptake include methylclonazepam, metergoline, imipramine, and ouabain. Maximal inhibition by these compounds ranged from 50 to 60%. Inhibition appeared to be confined to the saturable uptake component of the body fraction.
D001570:Benzodiazepinones / Q000494:pharmacology; D005260:Female; D007099:Imipramine / Q000494:pharmacology; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D008297:Male; D008711:Metergoline / Q000494:pharmacology; D012550:Schistosoma mansoni / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology; D014326:Tropanes / Q000494:pharmacology; D002998:Clonazepam / Q000031:analogs & derivatives
D001570:Benzodiazepinones; D007099:Imipramine; D008238:Lysergic Acid Diethylamide; D008711:Metergoline; D012701:Serotonin; D012702:Serotonin Antagonists; D014326:Tropanes; C042253:bemesetron; C020602:meclonazepam; D002998:Clonazepam