What is the role of adenosine receptors?

Adenosine receptors (ARs) comprise a group of G protein-coupled receptors (GPCR) which mediate the physiological actions of adenosine. These receptors have distinct localization, signal transduction pathways and different means of regulation upon exposure to agonists.

What do a1 and a2 receptors do?

Each type of adenosine receptor has different functions, although with some overlap. For instance, both A1 receptors and A2A play roles in the heart, regulating myocardial oxygen consumption and coronary blood flow, while the A2A receptor also has broader anti-inflammatory effects throughout the body.

What drug blocks adenosine?

An adenosine receptor antagonist is a drug which acts as an antagonist of one or more of the adenosine receptors. Examples include caffeine, theophylline, and theobromine.

What is adenosine and how does it work?

Adenosine is a chemical found in human cells. Adenosine blocks electrical signals in the heart that cause irregular heart rhythms. ATP might also prevent changes in energy metabolism that cause weight loss in people with advanced cancer.

How does sleep remove adenosine?

During wakefulness, adenosine levels gradually increase in areas of the brain that are important for promoting arousal, especially the reticular activating system in the brainstem. 3 With higher and higher concentrations, adenosine inhibits arousal and causes sleepiness. Then, adenosine levels decrease during sleep.

What do a2 receptors do?

Alpha 2 receptors in the brain stem and in the periphery inhibit sympathetic activity and thus lower blood pressure. Alpha 2 agonists lower blood pressure in many patients either alone or in combination with diuretics. Central nervous side effects are less common when lower doses are used.

Is caffeine an adenosine blocker?

Caffeine is considered an adenosine blocker. It comes into play by similarly attaching itself to the same receptors that adenosine would normally latch onto. In turn, it prevents the drowsiness that occurs as the levels of adenosine in the body increase.

Is coffee a antagonist?

The stimulant effect of coffee comes largely from the way it acts on the adenosine receptors in the neural membrane. Caffeine acts as an adenosine-receptor antagonist. This means that it binds to these same receptors, but without reducing neural activity.