Portal de Periódicos da CAPES

Repeated administration of (−) sulpiride and SCH 23390 differentially up-regulate D-1 and D-2 dopamine receptor function in rat mesostriatal areas but not in cortical-limbic brain regions

1987; Elsevier BV; Volume: 138; Issue: 1 Linguagem: Inglês

10.1016/0014-2999(87)90335-9

1879-0712

Maurizio Memo, Marina Pizzi, Enzo Nisoli, Cristina Missale, Michele O. Carruba, PierFranco Spano,

Neurotransmitter Receptor Influence on Behavior

We studied the possible function modifications of both D-1 and D-2 dopamine (DA) receptor subtypes following repeated administration of DA antagonists that act selectively on a single class of DA receptors. The functional state of D-1 and D-2 DA receptors in particular was evaluated by measuring SKF 82526-stimulated and bromocriptine-inhibited adenylate cyclase activity in different brain regions of rats treated with saline, SCH 23390, or (−)sulpiride for 21 days. The results indicate that chronic blockade of D-1 DA receptors in striatum, nucleus accumbens, and substantia nigra by SCH 23390 induced up-regulation of the D-1 receptors without changing the functional activity of D-2 receptors. Likewise, chronic blockade of D-2 DA receptors by (−) sulpiride caused up-regulation of D-2 but not D-1 DA receptors in striatum, nucleus accumbens, substantia nigra and pituitary. SCH 23390 or (−)sulpiride did not modify the functional activity of either D-1 or D-2 DA receptors located in frontal cortex and hippocampus. In conclusion, these results indicate that chronic treatment with selective D-1 or D-2 DA receptor blockers induces a receptor-specific up-regulation which involves the DA receptors located in the nigrostriatal system and pituitary but not those in the limbic-cortical areas.