Search results
Results From The WOW.Com Content Network
An adenosine reuptake inhibitor (AdoRI) is a type of drug which acts as a reuptake inhibitor for the purine nucleoside and neurotransmitter adenosine by blocking the action of one or more of the equilibrative nucleoside transporters (ENTs).
Caffeine's stimulatory effects are credited primarily (although not entirely) to its capacity to block adenosine receptors, thereby reducing the inhibitory tonus of adenosine in the CNS. This reduction in adenosine activity leads to increased activity of the neurotransmitters dopamine and glutamate . [ 35 ]
It also causes a negative dromotropic effect through the inhibition of AV-nodal conduction. [20] From the 1980s onwards, these effects of adenosine have been used in the treatment of patients with supraventricular tachycardia. [21] The regulation of vascular tone in the endothelium of blood vessels is mediated by purinergic signalling.
This makes adenosine a useful medication for treating and diagnosing tachyarrhythmias, or excessively fast heart rates. This effect on the A 1 receptor also explains why there is a brief moment of cardiac standstill when adenosine is administered as a rapid IV push during cardiac resuscitation. The rapid infusion causes a momentary myocardial ...
Adenosine is a neuromodulator that is responsible for motor function, mood, memory, and learning. Its main purpose is the coordination of responses to different neurotransmitters. [5] Adenosine plays many important roles in biological systems, for example in the central nervous-, cardiovascular-, hepatic-, renal- and respiratory system.
Adenosine receptor antagonism also promotes neurotransmitter release (e.g., monoamines and acetylcholine), which endows caffeine with its stimulant effects; [5] [169] adenosine acts as an inhibitory neurotransmitter that suppresses activity in the central nervous system. Heart palpitations are caused by blockade of the A 1 receptor. [5]
P2Y 12 is a chemoreceptor for adenosine diphosphate (ADP) [5] [6] that belongs to the G i class of a group of G protein-coupled (GPCR) purinergic receptors. [7] This P2Y receptor family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides.
Abundant extracellular adenosine can then bind to the A2A receptor resulting in a G s-protein coupled response, resulting in the accumulation of intracellular cAMP, which functions primarily through protein kinase A to upregulate inhibitory cytokines such as transforming growth factor-beta (TGF-β) and inhibitory receptors (i.e., PD-1). [56]