What is the main mechanism by which caffeine is thought to interact when present in physiologically relevant concentrations?
Caffeine is thought to primarily antagonize adenosine receptors. According to the cited reference, caffeine antagonizes the A1 (brain, spinal cord, eye, adrenal gland, heart, and skeletal muscle and adipose tissue), A2A (spleen, thymus, striatopallidal GABAergic neurons, heart, lung, and blood vessels), and A2B (cecum, colon, bladder, and bronchial smooth muscle) adenosine receptors. This action affects the release of neurotransmitters (dopamine, GABA, and glutamate), causes inhibition of neurotransmission, and affects locomotive behavior.
Willson C. The clinical toxicology of caffeine: A review and case study. Toxicol Rep. 2018;5:1140-1152. Published 2018 Nov 3. doi:10.1016/j.toxrep.2018.11.002
Contributed by Ryan Munch, MD Candidate