Effects of chronic lithium treatment on serotonin binding sites in rat brain.
The effects of lithium treatment on serotonin (5-HT) binding sites in the rat brain were investigated. Oral administration of lithium carbonate for 3 weeks did not influence 5-HT2 binding sites in the cerebral cortex. On the other hand, the number of 5-HT1 binding sites labeled with [3H]5-HT was decreased significantly in the hippocampus, but not in the cerebral cortex. While non-5-HT1A sites, defined as specific [3H]5-HT binding in the presence of 100 nM 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), were not affected by lithium treatment in either brain region, chronic lithium administration reduced significantly the density of 5-HT1A sites labeled with [3H]8-OH-DPAT only in the hippocampus, but not in the cerebral cortex. These results suggest that 5-HT1A components are responsible for lithium-induced down-regulation of 5-HT1 binding sites in the hippocampus and that 5-HT1A sites in the hippocampus might be connected with the therapeutic efficacy of lithium.
Odagaki
Y
Y
Department of Psychiatry and Neurology, Hokkaido University School of Medicine, Sapporo, Japan.
Koyama
T
T
Matsubara
S
S
Matsubara
R
R
Yamashita
I
I
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects; D008094:Lithium / Q000494:pharmacology*; D016651:Lithium Carbonate; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism
D011985:Receptors, Serotonin; D016651:Lithium Carbonate; D012701:Serotonin; D008094:Lithium