Adenosine A1 receptor activation inhibits basal accumulation of inositol phosphates in rat hippocampus.
The ability of the adenosine A1 receptor selective agonist, N6-cyclopentyladenosine, to modify basal accumulation of inositol phosphates in rat hippocampal slices, was investigated. Cyclopentyladenosine (10-300 nM) inhibited the basal accumulation of total [3H]inositol phosphates, with an EC50 of 10 nM and an Emax of 24%. This effect of cyclopentyladenosine was prevented by the adenosine A1 receptor selective antagonist, 1,3-dipropyl-8-cyclopentylxanthine (30 nM). Cyclopentyladenosine (100 nM) also inhibited histamine (300 nM)-stimulated accumulation of [3H]inositol phosphates, this effect being quantitatively similar to that observed on basal [3H]inositol phosphates accumulation. The results suggest that adenosine A1 receptor activation is able, per se, to inhibit the formation of phosphatidylinositol-derived second messengers in hippocampus.
Cascalheira
J F
JF
Department of Chemistry, University Beira Interior, Covilhã, Portugal.
Sebastião
A M
AM
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism*; D008297:Male; D058906:Purinergic P1 Receptor Agonists; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000187:drug effects* / Q000378:metabolism
D007295:Inositol Phosphates; D058906:Purinergic P1 Receptor Agonists; D018047:Receptors, Purinergic P1; C048599:N(6)-cyclopentyladenosine; D000241:Adenosine