Uptake and liberation of mepacrine in blood platelets.
1. Isolated platelets of guinea pigs incubated in Tyrode showed a rapid accumulation of 14C-mepacrine which was less dependent on temperature than that of 14C-5-hydroxytryptamine (5HT). 2. The uptake of mepacrine was not inhibited by imipramine, cocaine, ouabain, KCN, NaF, and reserpine. 3. Various 5HT-liberating drugs, e.g. Ro 4-1284 (benzoquinolizine derivative with reserpine-like action), amphetamine, tyramine and imipramine did not markedly affect the 14C-mepacrine content of platelets previously loaded with this compound. 4. Thrombin and chlorpromazine caused a liberation of 14C-mepacrine from the platelts which was however, less pronounced than that of 14C-5HT. 5. From these and previous findings it is concluded that 14C-mepacrine accumulates in the 5HT storage organelles by a reserpine-insensitive mechanism not dependent on an active transport at the cytoplasmatic membrane level.
D012369:2H-Benzo(a)quinolizin-2-ol, 2-Ethyl-1,3,4,6,7,11b-hexahydro-3-isobutyl-9,10-dimethoxy- / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism* / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism; D002746:Chlorpromazine / Q000494:pharmacology; D003042:Cocaine / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D005260:Female; D005459:Fluorides / Q000494:pharmacology; D006168:Guinea Pigs; D007099:Imipramine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D011796:Quinacrine / Q000097:blood*; D012110:Reserpine / Q000494:pharmacology; D012701:Serotonin / Q000097:blood; D013696:Temperature; D013917:Thrombin / Q000494:pharmacology
D003486:Cyanides; D012369:2H-Benzo(a)quinolizin-2-ol, 2-Ethyl-1,3,4,6,7,11b-hexahydro-3-isobutyl-9,10-dimethoxy-; D012701:Serotonin; D010042:Ouabain; D012110:Reserpine; D013917:Thrombin; D011796:Quinacrine; D003042:Cocaine; D007099:Imipramine; D005459:Fluorides; D002746:Chlorpromazine