Dopamine D3 receptor density elevation in aged Fischer-344 x Brown-Norway (F1) rats.
The density of dopamine D3 receptors was determined in young (4-month-old) and aged (37-month-old) Fischer-344 x Brown-Norway (F1) male rats using the putative D3 receptor-preferring agonist, [3H](+)-7.hydroxy-2-(N,N-di-n-propylamino)tetralin ([3H](+)-7-OH-DPAT). In the presence of the non-hydrolyzable GTP analog, 5'-guanylylimidodiphosphate (Gpp(NH)p), the density of dopamine D3 receptors in the striatum and nucleus accumbens was significantly increased (29-102%, respectively) in aged Fischer-344 x Brown-Norway (F1) rats compared to young adults. These findings suggest that dopaminergic activity in aged rats is compromised by increased D3 receptor density, resulting in altered striatal/nucleus accumbens function via presynaptic or postsynaptic modifications.
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University of Kentucky Medical Center, Department of Pharmacology, Lexington 40536-0084, USA.
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D000375:Aging / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism*; D003433:Crosses, Genetic; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3
C493595:Drd3 protein, rat; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3