Fig. 6
From: Transporter-dependent uptake and metabolism of myocardial interstitial serotonin in the rat heart
Putative mechanisms regulating cardiac interstitial level of 5-HT in a physiological condition. Interstitial level of 5-HT in the heart is maintained low mostly by fluoxetine-sensitive transporter (SERT) dependent uptake into platelets and stored in intracellular vesicles. This stored 5-HT in the vesicle could be reused and less metabolized. Meanwhile, interstitial 5-HT is also taken up by decynium-22 sensitive transporter (PMAT) into cardiac cells. The transported 5-HT is then metabolized by MAO to produce 5-HIAA