Influence of long-term lithium treatment on 5-hydroxytryptamine-mediated stimulation of adenylate cyclase in guinea-pig hippocampus.
The effects of long-term lithium treatment on the 5-hydroxytryptamine-mediated stimulation of adenylate cyclase activity in guinea-pig hippocampal membranes were examined. The stimulatory effect of 5-hydroxytryptamine on adenylate cyclase activity was guanine nucleotide-dependent and additive to those of dopamine, isoproterenol, norepinephrine, epinephrine and histamine. In contrast, the adenylate cyclase activity stimulated by 10 microM of 5-hydroxytryptamine plus 10 microM of 8-OH-DPAT was quite equal to that stimulated by 10 microM of 5-hydroxytryptamine alone. Oral administration of lithium for 3 weeks reduced, slightly but significantly, the concentration-response curve to 5-hydroxytryptamine but did not alter that to 8-OH-DPAT. Inhibition of the forskolin-stimulated adenylate cyclase activity by 5-hydroxytryptamine or 8-OH-DPAT was shown to be unaltered after lithium treatment. The implications of these results are discussed with reference to previously reported data using hippocampal membranes prepared from rats.
Odagaki
Y
Y
Department of Psychiatry and Neurology, Hokkaido University School of Medicine, Sapporo, Japan.
Koyama
T
T
Yamashita
I
I
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006168:Guinea Pigs; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology*; D066298:In Vitro Techniques; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*
D005576:Colforsin; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D006160:Guanosine Triphosphate; D008094:Lithium; D000262:Adenylyl Cyclases