adenosiin

Adenosine is a nucleoside, a molecule composed of a purine base, adenine, and a sugar, ribose. It plays a crucial role in numerous biological processes within the human body and other organisms. One of its most well-known functions is as a neurotransmitter in the central nervous system. Adenosine is released by nerve cells and binds to specific adenosine receptors on other neurons, generally inhibiting their activity. This inhibitory action contributes to feelings of calmness and sleepiness, and its levels increase throughout the day, promoting the urge to sleep.

Beyond its role in the brain, adenosine is also a fundamental building block of nucleic acids, DNA and RNA, where adenine is one of the four bases. It is also a component of adenosine triphosphate (ATP), the primary energy currency of cells. ATP stores and releases energy through the breaking and forming of phosphate bonds, a process directly involving adenosine. Furthermore, adenosine has effects on the cardiovascular system, acting as a vasodilator, meaning it widens blood vessels, which can lower blood pressure. In certain medical contexts, adenosine is administered intravenously to treat specific types of abnormal heart rhythms, known as supraventricular tachycardias.