Pharmacological characterization of serotonin receptors involved in the control of prolactin secretion.
The present study was undertaken to characterize the type of serotonin (5-HT) receptors involved in the control of prolactin (PRL) secretion in male rats. d-Fenfluramine (10 mg/kg i.p.), a potent 5-HT releaser and quipazine, (20 mg/kg i.p.) a 5-HT agonist, caused a marked increase in serum PRL levels. Ritanserin (200 micrograms/kg i.p.), a specific antagonist of 5-HT2 receptors, administered 1 h before the administration of d-fenfluramine or quipazine, completely prevented the PRL-releasing effect of these drugs. Furthermore, the administration of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH DPAT) (1.5, 3 and 6 mg/kg i.p.), a compound considered to be a prototypical 5-HT1A agonist, failed to induce any change in serum PRL levels. The same lack of effect on PRL secretion was observed after the administration of 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridin-4-yl)-1-H-indole (RU 24969) (1, 3 and 10 mg/kg i.p.), a compound which has been shown to possess a higher selectivity for 5-HT1B receptor subtypes than for 5-HT1A subtypes. These results suggest that 5-HT receptors involved in the control of PRL secretion are of the 5-HT2 type.
Di Renzo
G
G
Department of Pharmacology, 2nd School of Medicine, Naples, Italy.
Amoroso
S
S
Taglialatela
M
M
Canzoniero
L
L
Basile
V
V
Fatatis
A
A
Annunziato
L
L
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D005277:Fenfluramine / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D010880:Piperidines / Q000494:pharmacology; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D011814:Quipazine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D016713:Ritanserin; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
D007211:Indoles; D010880:Piperidines; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D016713:Ritanserin; D005277:Fenfluramine; C025145:5-methoxy 3-(1,2,3,6-tetrahydro-4-pyridinyl)1H indole; D011814:Quipazine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D011388:Prolactin