Desensitization and internalization of adenosine A1 receptors in rat brain by in vivo treatment with R-PIA: involvement of coated vesicles.
Biochim Biophys Acta
; 1310(1): 168-74, 1996 Jan 10.
Article
in En
| MEDLINE
| ID: mdl-9244192
ABSTRACT
Chronic treatment of rats with R-PIA 'in vivo' desensitized adenosine A1 receptor-mediated inhibition of adenylyl cyclase in brain plasma membranes and increased basal and forskolin-stimulated adenylyl cyclase. The adenosine A1 receptor agonist CHA (cyclohexyl adenosine) inhibited forskolin-stimulated adenylyl cyclase in synaptic plasma membranes from control rats but failed to do so in membranes isolated from rats treated with R-PIA. This loss of response was accompanied with a significant decrease in both, total number of adenosine A1 receptors and steady-state level of alpha-Gi in synaptic plasma membranes. An increase in the steady-state level of alpha-Gs in synaptic plasma membranes was also observed by R-PIA treatment. Concurrently, a significant increase of adenosine A1 receptors was observed in microsomes and coated vesicles. These results demonstrate adenosine A1 receptor desensitization in rat brain by 'in vivo' treatment with R-PIA and suggest a role for coated vesicles in the internalization of G-protein coupled receptors.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Vasodilator Agents
/
Brain
/
Adenosine
/
Receptors, Purinergic P1
/
Coated Vesicles
Limits:
Animals
Language:
En
Journal:
Biochim Biophys Acta
Year:
1996
Document type:
Article
Affiliation country: