DOPAMINE D-2 RECEPTOR EFFECTS ON GABA(A) RECEPTOR EXPRESSION MAY MODIFY MELANOTROPE PEPTIDE RELEASE

Stimulation of melanotrope dopamine D-2 receptors decreases mitotic ra te, calcium channel activity, and the biosynthesis of several proteins . This study demonstrates that D-2 receptor activation also affects GA BA(A) receptor beta(2)/beta(3) subunit immunoreactivity. Following chr onic treatment with haloperidol, a D-2 receptor antagonist, GABA(A) re ceptor immunoreactivity increased, whereas it decreased after chronic treatment with bromocriptine, a dopamine D-2 receptor agonist. Thus, t hese data indicate that D-2 function regulates GABA(A) receptor expres sion in melanotropes, a mechanism by which peptide release may be modi fied. (C) 1998 Elsevier Science Inc.