Key result
Pharmacological anoxia increased interstitial serotonin concentration, an effect blocked by fluoxetine, indicating carrier-mediated serotonin efflux via SERT during ischaemia.
Why the study?
Serotonin accumulates in the heart during myocardial ischaemia and harms cardiomyocytes, prompting investigation into whether carrier-mediated serotonin efflux contributes to increased interstitial levels during ischaemia.
Reverse transport of serotonin via SERT contributes to the rise in interstitial serotonin levels during myocardial ischemia in vivo.
Serotonin (5-HT) accumulates in the heart during myocardial ischaemia and induces deleterious effects on the cardiomyocytes. We aimed to investigate whether carrier-mediated 5-HT efflux contributed to the increase in interstitial 5-HT level during ischaemia. Using microdialysis technique applied to the heart of anaesthetised Wistar rats, myocardial interstitial concentration of 5-HT was measured by electro-chemical detection coupled with high-performance liquid chromatography (HPLC-ECD) while simultaneously various pharmacological agents, which create a similar condition to ischaemia, were locally administered by reverse-microdialysis. Sodium cyanide-induced chemical anoxia increased dialysate 5-HT concentration. A similar increase in dialysate 5-HT concentration was induced by ouabain, an inhibitor of sodium-potassium ATPase and reserpine, an inhibitor of vesicular monoamine transporter. Fluoxetine, a selective serotonin reuptake inhibitor raised the baseline level of 5-HT, and neither sodium cyanide nor the combination of ouabain and reserpine induced further increase in 5-HT in the presence of fluoxetine. The results indicate that reverse transport of 5-HT via SERT, which is caused by an impaired ion gradient, contributes to the rise in interstitial level of 5-HT during ischaemia suggesting carrier-mediated 5-HT efflux occurs in the heart in vivo.
No takes yet. Share an insight, caveat, or question.
Sonobe et al. (2021) studied Myocardial ischaemia. Pharmacological anoxia (sodium cyanide, ouabain, reserpine, fluoxetine) was evaluated on Myocardial interstitial concentration of serotonin (5-HT). Pharmacological anoxia increased interstitial serotonin concentration, an effect blocked by fluoxetine, indicating carrier-mediated serotonin efflux via SERT during ischaemia.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: