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The accumulation and metabolism of dopamine by the human platelet
Author(s) -
Solomon Harvey M.,
Spirt Nena M.,
Abrams William B.
Publication year - 1970
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt1970116838
Subject(s) - chemistry , benztropine , platelet , dopamine , pharmacology , metabolism , endocrinology , medicine , sodium cyanide , biochemistry , cyanide , inorganic chemistry
Human blood platelets incubated for one hour at 37° C. with dopamine‐l‐ 14 C (DA) accumulated the amine against a gradient. Such accumulation was markedly reduced by cold and by various metabolic inhibitors including iodoacetate, dinitrophenol, and sodium cyanide. Increasing the concentration of DA caused a decrease in the steady‐state distribution ratio which suggests that the uptake process is saturable. Various compounds which inhibit or compete for the amine pump in the platelet membrane, including desmethylimpromine (DMI), diphenhydramine, serotonin, debrisoquin, and guanethidine, depress the accumulation of DA. Uptake of DA was also reduced by benztropine, trihexyphenidyl, and haloperidol. Less than 10 per cent of the DA which accumulates in the platelet during one hour is metabolized. DA is a relatively poor substrate for platelet MAO and in addition the cell does not appear to contain dopamine β‐hydroxylase.