Table 5

Functional distribution of endogenously expressed A2 adenosine receptors in central and peripheral nervous systems

LocationSubtypeEffectsReference
CNS
 Caudate-putamen synaptosomesA2A ↓ K+-evoked GABA release Kurokawa et al., 1994
 Cerebral cortexA2(A) ↓ Neuronal firing Phillis, 1990; Lin and Phillis, 1991
 Cerebral cortexA2(B) ↑ ACh- and K+-evoked aspartate release Phillis et al., 1993a,b
 Cerebral cortexA2A ↓ Ischemia-evoked GABA release O’Reganet al., 1992a
 Cerebral cortexA2A ↓ Ischemia-evoked glutamate and aspartate release O’Regan et al., 1992b
 Globus pallidusA2A ↑ Electrically evoked GABA release Mayfield et al., 1993
 Globus pallidus synaptosomesA2A ↓ K+-evoked GABA release Kurokawa et al., 1994
 HippocampusA2A ↑ Electrically evoked [14C]ACh release Jin and Fredholm, 1997
 Hippocampus (CA3 region)A2A ↑ Electrically evoked [3H]ACh release Cunha et al., 1994
 Hippocampus (CA3 region)A2 ↑ P-type calcium currents Mogul et al., 1993
 Hippocampal synaptosomesA2A ↑ Veratridine-evoked [3H]ACh release Cunha et al., 1995
 Nucleus accumbensA2A ↓ Locomotor activity (baroreceptor ↓, chemoreceptor ↑) Barraco et al., 1993, 1994
 Nucleus tractus solitariusA2A Baroreflex control (hypotension, bradycardia) Barraco et al., 1993; Ergeneet al., 1994
A2A ↑ Electrically evoked [3H]NA release Barraco et al., 1995
A2A ↓ K+-evoked glutamate release Castillo-Meléndez et al., 1994
 StriatumA2A Catalepsy Hauber and Munkle, 1995
 StriatumA2 ↑ Dopamine release Zetterström and Fillenz, 1990
 StriatumA2A ↑ ACh release Brown et al., 1990; Kurokawa et al., 1994
 StriatumA2A ↑ Veratridine-evoked [3H]ACh release Kirkpatrick and Richardson, 1993
 StriatumA2A ↓ NMDA receptor conductance Nörenberg et al., 1997b
 Striatal synaptosomesA2A ↓ K+-evoked GABA release Kirk and Richardson, 1995
 Superior colliculusA2A ↑ Evoked potentials Ishikawa et al., 1997
 Spinal cordA2 Antinociception DeLander and Hopkins, 1987
PNS
 Motor nerves; phrenic nerve-hemidiaphragmA2A ↑ Electrically and CGRP-evoked [3H]ACh release Correia-de-Sá and Ribeiro, 1994a,b;Correia-de-Sá et al., 1996
 Myenteric neuronesA2A ↑ Excitability Christofi et al., 1994
 Airway sensory neuronesA2(A) ↓ Capsaicin-evoked substance P release Morimoto et al., 1993
 Vagal afferent neuronesA2A Depolarization Castillo-Melendez et al., 1994
 Vas deferens neuronesA2A ↑ Electrically evoked NA release Gonçalves and Queiroz, 1993
 Rat tail artery neuronesA2A ↑ Electrically evoked NA release Gonçalves and Queiroz, 1996