Involvement of the 5-HT2 receptor in the 5-HT receptor-mediated stimulation of prolactin release.
The present study examined the involvement of 5-HT1C and 5-HT2 receptors in the regulation of prolactin release in the rat. Both the mixed 5-HT2/5-HT1C receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), and the preferential 5-HT1C agonist, 2-chloro-6-(1-piperazinyl)pyrazine monohydrochloride (MK-212), elicited a significant increase in plasma prolactin concentration with DOI about 20 times more potent than MK-212. Treatment with DOI, but not with MK-212, induced head twitching in the rat, and this behavior was inhibited by both the mixed 5-HT2/5-HT1C receptor antagonist, ritanserin, and the selective 5-HT2 receptor antagonist, amperozide. DOI-induced prolactin release was also antagonized by ritanserin and amperozide, whereas only ritanserin affected MK-212-induced prolactin release. Furthermore, amperozide did not attenuate d-fenfluramine-elicited prolactin release, which is known to be antagonized by ritanserin. These data suggest that the pharmacological stimulation of prolactin release by DOI is mediated via the 5-HT2 receptor and that the 5-HT1C receptor may be of importance for the physiological regulation of prolactin release.
Albinsson
A
A
Kabi Pharmacia AB, Department of CNS Research, Malmö, Sweden.
Palazidou
E
E
Stephenson
J
J
Andersson
G
G
D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D011719:Pyrazines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000502:physiology*; D016713:Ritanserin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D000662:Amphetamines; D010879:Piperazines; D011719:Pyrazines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C049058:amperozide; D016713:Ritanserin; C014896:6-chloro-2-(1-piperazinyl)pyrazine; D011388:Prolactin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine