Inhibition of reserpine, guanethidine and imiparmine of the uptake of 5-hydroxytryptamine by rat peritoneal mast cells in vitro.
The effect of reserpine, guanethidine and imipramine of the uptake of tritiated 5-hydroxytryptamine by rat peritoneal mast cells was studied in vitro. The Km value for uptake of 5-hydroxytryptamine was 3 x 10(-7) M in this study. Kinetic analysis of the data obtained suggests that the drugs inhibits the uptake in a competitive manner, in the order of decreasing potency: reserpine, imipramine, guanethidine. For reserpine the Dixon plot resulted in two curves, each composed of 2 linear components suggesting inhibition of uptake of 5-hydroxytryptamine at 2 different levels or by 2 different mechanisms with different K1 values. It is suggested that the higher K1 value, representing an immediate effect of reserpine, stands for inhibition of uptake at the cell membrane. The lower K1 value possibly represents inhibition at the level of the membrane surrounding the intracellular storage organelles.
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006145:Guanethidine / Q000494:pharmacology*; D007099:Imipramine / Q000494:pharmacology*; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D051381:Rats; D012110:Reserpine / Q000494:pharmacology*; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors
D012701:Serotonin; D012110:Reserpine; D007099:Imipramine; D006145:Guanethidine