This study concluded that serotonin may potentially accelerate a cardiac condition known as generative mitral regurgitation. DMR is one of the most common cardiac diseases. The left atrium and left ventricle of the heart are where the mitral valve is situated. When the heart contracts, it closes tightly to stop blood from flowing back into the left atrium. DMR can therefore result in symptoms including exhaustion and shortness of breath. The heart has to work harder as a result of the decreased circulation efficiency, which over time results in lasting harm. The deterioration of the mitral valve is now untreatable. 

Serotonin is involved in many bodily processes, including mood, digestion, sleep, memory, and blood coagulation. Your brain uses serotonin as a neurotransmitter to control mood; anxiety and depression are linked to low serotonin levels. A cell receives a signal from serotonin to function appropriately when it binds to particular receptors on the surface of the cell. Serotonin is transported into the cell by a protein called the serotonin transporter (SERT or 5-HTT), where it is reabsorbed and regenerated. 

Serotonin-2D-skeletal

Serotonin can stay available for longer lengths of time thanks to medications known as selective serotonin reuptake inhibitors (SSRIs), which bind to the SERT and decrease serotonin reuptake. Some examples of SSRIs are medications such as fluoxetine (Prozac) and sertraline (Zoloft). 

The study assessed 100 mitral valve samples and clinical data from over 9,000 patients who had undergone valve repair or replacement surgery for DMR. In analyzing the data of these patients, Ferrari and colleagues discovered that SSRI use was linked to severe mitral regurgitation that required surgery at a younger age than in those who did not take SSRIs.

ZOLOFT (sertraline HCI) Crop

Additionally, the researchers used normal and transgenic mice lacking the SERT gene to study in vivo mouse models. They found that normal mice treated with high doses of SSRIs also had thickened mitral valves, and that mice lacking the SERT gene similarly acquired thicker mitral valves. The researchers discovered genetic variations in the 5-HTTLPR region of the SERT gene that have an impact on SERT function using genetic analysis.

One thing we have learned this far in AP Biology is that a receptor is a protein that can bind to a molecule. Different receptors cause different effects in the cell. Receptors are specialized proteins found on the surface or inside cells that are able to recognize and respond to specific chemical signals, such as hormones, neurotransmitters, and other signaling molecules. These signals can trigger a range of cellular responses, including changes in gene expression, alterations in cellular metabolism, or changes in the electrical properties of cells. Receptors are essential for many physiological processes, including sensory perception, regulation of the nervous and endocrine systems, and immune responses. There are many different types of receptors, including ion channels, G protein-coupled receptors, and enzyme-linked receptors, each with their own unique structure and function.

Androgen receptor 3-d model

I think this is very interesting considering that people did not know that SSRI use led to severe mitral regurgitation. People had to have surgery at young age to fix this. Many individuals would not have had to go through with a medical procedure if they knew what was causing this.