Age-related changes in rat serotonergic and adrenergic systems and in receptor responsiveness to subchronic desipramine treatment.
Noradrenergic (NA) and serotonergic (5-HT) receptor profiles were compared in the cerebral cortex of young adult (3 months old) and aged (24 months old) male Sprague Dawley rats. Beta and alpha-1 receptors were significantly decreased in 24 month old rats, whereas alpha-2 receptors remained unchanged. 5-HT-2 Postsynaptic receptors and 5-HT high affinity uptake were reduced in aged animals; on the other hand the number of 3H-imipramine (3H-IMI) recognition sites located on serotonin nerve terminals and labelled also by 3H-paroxetine (3H-PAR), were significantly higher in the cerebral cortex of old rats. The ratio 5-hydroxyindoleacetic acid (5-HIAA)/5-HT, an index of serotonin turn-over, increased in some brain areas of senescent rats. There were no age-related changes in the responsiveness of investigated binding sites to subchronic desipramine treatment; the density of beta-noradrenergic and 5-HT-2 serotonergic receptors and that of 3H-IMI binding sites was reduced both in young adult and aged rats.
Brunello
N
N
Center of Neuropharmacology, University of Milano, Italy.
Riva
M
M
Rovescalli
A C
AC
Galimberti
R
R
Racagni
G
G
D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000378:metabolism; D003000:Clonidine / Q000378:metabolism; D003891:Desipramine / Q000008:administration & dosage / Q000494:pharmacology*; D004082:Dihydroalprenolol / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007099:Imipramine / Q000378:metabolism; D007650:Ketanserin / Q000378:metabolism; D007700:Kinetics; D008297:Male; D017374:Paroxetine; D010880:Piperidines / Q000378:metabolism; D011224:Prazosin / Q000378:metabolism; D011506:Proteins / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism; D013997:Time Factors
D010880:Piperidines; D011506:Proteins; D011941:Receptors, Adrenergic; D011985:Receptors, Serotonin; D012701:Serotonin; D017374:Paroxetine; D006897:Hydroxyindoleacetic Acid; D004082:Dihydroalprenolol; D007650:Ketanserin; D003000:Clonidine; D007099:Imipramine; D003891:Desipramine; D011224:Prazosin