Regulation of 5-hydroxytryptamine1A receptor function in rat hippocampus by short- and long-term administration of 5-hydroxytryptamine1A agonist and antidepressants.
Single s.c. injections of the 5-hydroxytryptamine (5-HT)1A receptor agonists buspirone at 4 mg/kg, 8-hydroxy-2-(di-n-propylamino)tetralin at 1 or 4 mg/kg or ipsapirone at 10 mg/kg did not affect 5-HT inhibition of forskolin-stimulated adenylate cyclase activity in rat hippocampal membranes. However, a single injection of buspirone at 8 mg/kg, and daily injections of each of the agonists for 8 days, resulted in a reduction in the degree of enzyme inhibition by 5-HT. Chronic administration of the antidepressants fluoxetine, zimelidine and maprotiline by i.p. injections at 15 mg/kg for 3 weeks also resulted in a decreased degree of enzyme inhibition. Chronic iprindole at the same dose had no effect. It is concluded that the antidepressant-like properties of 5-HT1A receptor agonists may be mediated partly by a postsynaptic action at the level of serotonergic second messenger transduction in the hippocampus.
Newman
M E
ME
Ya'acov Herzog Center for Brain and Psychiatry Research, Ezrath Nashim Hospital, Jerusalem, Israel.
Shapira
B
B
Lerer
B
B
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D005576:Colforsin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006624:Hippocampus / Q000502:physiology / Q000648:ultrastructure*; D008297:Male; D008376:Maprotiline / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D013997:Time Factors; D015031:Zimeldine / Q000494:pharmacology
D000928:Antidepressive Agents; D011985:Receptors, Serotonin; D005576:Colforsin; D008376:Maprotiline; D012701:Serotonin; D015031:Zimeldine; D000262:Adenylyl Cyclases