Relationship between internal Na + -K +  and the accumulation of  14 C-5-hydroxytryptamine by rat platelets.
1. 5-Hydroxytryptamine (5-HT) transport has been investigated in rat blood platelets poisoned with dinitrophenol-sodium fluoride or ouabain.2. The inhibition of transport produced by different concentrations of the metabolic inhibitors has been correlated with changes in the internal Na(+) and K(+) concentrations of the platelets.3. Platelets poisoned in a high K(+) medium maintained a high internal K(+) concentration in the absence of cellular metabolism. When transferred to Krebs solutions containing different concentrations of Na(+) they accumulated 5-HT by a process that was related to the magnitudes of the internal and external Na(+) concentrations.4. The results are consistent with the hypothesis that the spontaneous movement of ions through the platelet membrane is capable of providing, at least in part, the energy requirements for 5-HT transport.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002247:Carbon Isotopes; D004140:Dinitrophenols / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
D002247:Carbon Isotopes; D004140:Dinitrophenols; D012701:Serotonin; D010042:Ouabain; D012964:Sodium; D011188:Potassium