Possible Interaction: Potassium and Serotonin

“In the aneurysm group, significantly stronger contractions were demonstrated upon exposure to potassium and 5-hydroxytryptamine.”

“Later it has been proved that a large amount of 5-HT injected in the vein of the back of the hand did not provoke pain, but highly increased the pain producing action of bradykinin and potassium (Sicuteri et al. 1965).”

“Thus, 5-HT enhances two different cation currents and reduces potassium currents.”

“In the presence of serotonin , increasing extracellular potassium concentration from 5.4 to 20 mmol/l depolarizes the cell membrane by +26.4±1.0 mV (n=11).”

“The potassium (25 mmol/l)-evoked tritium overflow from cortex synaptosomes was inhibited by 5-HT ; the inhibitory effect of 5-HT was counteracted by metitepine, which, by itself, did not affect the evoked overflow.”

“The peak current of the potassium currents of the neuron treated with 5-&agr;-methylhydroxytryptamine was decreased.”

“These results suggest 5-&agr;-methylhydroxytryptamine increases spontaneous firing of the medial vestibular nuclear neurons by inhibiting calcium dependent potassium currents.”

“ 5-HT also decreases the maximal conductance of a sustained potassium current [IK(V) ] without affecting its voltage dependence.”

“Local perfusion of the hypothalamus with dialysis solution containing 5-hydroxytryptophan (a 5-HT precursor), fluoxetine (a 5-HT reuptake inhibitor), or high potassium significantly increased both colonic temperature (Tco) and the extracellular concentrations of 5-HT in the hypothalamus.”

“Addition of potassium (K+, 120 mM) to the perfusion fluid evoked an approximately 3-fold increase in 5-HT release.”

“ Potassium induced dramatic release of serotonin.”