Adenosine A1 receptors modulate anxiety in CD1 mice.
The effect of the selective adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine (CCPA) was investigated in CD1 mice by the elevated plus-maze and the light/dark test, two models for measuring anxiety in rodents. CCPA, administered i.p., had an anxiolytic effect at 0.3 nmol/kg in the elevated plus-maze and at 1 nmol/kg in the light/dark test. Brain levels of 22 nM were found after administration of 100 nmol/kg CCPA, as measured by ex vivo binding experiments. These values are consistent with the occupancy of adenosine A1 but not A2 receptors by CCPA, and suggest that the anxiolytic-like action of CCPA may be mediated by centrally located adenosine A1 receptors. Both CPT, a selective adenosine A1 receptor antagonist, and IBMX, a non-selective adenosine antagonist, had an anxiogenic effect in the two tests. It is thus possible that purinergic neurons may be involved in the tonic modulation of affective state in mice.
Florio
C
C
Department of Biomedical Sciences, University of Trieste, Italy.
Prezioso
A
A
Papaioannou
A
A
Vertua
R
R
D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000627:therapeutic use; D000818:Animals; D014151:Anti-Anxiety Agents / Q000627:therapeutic use*; D001007:Anxiety / Q000188:drug therapy* / Q000503:physiopathology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D008027:Light; D008297:Male; D018782:Maze Learning; D051379:Mice; D058906:Purinergic P1 Receptor Agonists; D018047:Receptors, Purinergic P1 / Q000502:physiology
D014151:Anti-Anxiety Agents; D058906:Purinergic P1 Receptor Agonists; D018047:Receptors, Purinergic P1; C058394:2-chloro-N(6)cyclopentyladenosine; D000241:Adenosine