Produção Nacional
Revisado por pares
Adenosine A 1 Receptors in Cultured Cerebellar Granule Cells: Role of Endogenous Adenosine
1996; Wiley; Volume: 67; Issue: 4 Linguagem: Inglês
10.1046/j.1471-4159.1996.67041469.x
ISSN1471-4159
AutoresJuana María Sanz, Deusa Vendite, Mercedes Fernández, Antonio Andrés, Manuel Ros,
Tópico(s)Neurological Complications and Syndromes
ResumoAbstract: Adenosine A 1 receptors as well as other components of the adenylate cyclase system have been studied in cultured cerebellar granule cells. No significant changes in adenosine A 1 receptor number, assayed by radioligand binding in intact cells, were detected from 2 days in vitro (DIV) until 7 DIV. Nevertheless, a decline in this parameter was detected at 9 DIV. The steady‐state levels of α‐G s and α‐G i , detected by immunoblotting, showed similar profiles, increasing from 2 to 5 DIV and decreasing afterward. Forskolin‐stimulated adenylate cyclase levels also showed an increase until 5 DIV, decreasing at 7 and 9 DIV. The adenosine A 1 receptor analogue cyclopentyladenosine (CPA) was able to inhibit cyclic AMP accumulation at 2, 5, and 7 DIV but failed to do so at 9 DIV. This inhibition was prevented by the specific adenosine A 1 receptor antagonist 8‐cyclopentyl‐1,3‐dipropylxanthine. The presence of adenosine deaminase in the culture increased adenosine A 1 receptor number during the period studied and induced recovery of the inhibitory effect of CPA, lost after 7 DIV. These data suggest that functional expression of adenosine A 1 receptors and the other components of the adenylate cyclase system is subjected to regulation during the maturation of cultured cerebellar granule cells and demonstrates a key role for endogenous adenosine in the process.
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