A central 5-HT2 receptor mechanism plays a key role in the proestrous surge of luteinizing hormone in the rat.
The role of serotonin (5-HT) in generating the spontaneous preovulatory surge of luteinizing hormone (LH) has been investigated by studying the effect of ketanserin (a mixed 5-HT2/alpha 1 adrenoreceptor antagonist); the selective 5-HT2 receptor antagonist, ritanserin; and the selective alpha 1 adrenoreceptor antagonist, prazosin, on the plasma concentrations of LH during the afternoon of proestrus in conscious Wistar rats. Sequential blood samples for hormone estimation were taken through intra-atrial cannulae previously implanted under halothane anesthesia. All three drugs blocked the LH surge; ketanserin, but not ritanserin or prazosin, also blocked basal LH release. These results provide the first robust evidence for the fact that a 5-HT2 receptor as well as an alpha 1 adrenoreceptor mechanism is involved in the LH surge generator.
Dow
R C
RC
MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh, UK.
Williams
B C
BC
Bennie
J
J
Carroll
S
S
Fink
G
G
D000818:Animals; D005260:Female; D007650:Ketanserin / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000097:blood*; D011224:Prazosin / Q000494:pharmacology; D011359:Proestrus / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D016713:Ritanserin / Q000494:pharmacology
D011985:Receptors, Serotonin; D016713:Ritanserin; D007986:Luteinizing Hormone; D007650:Ketanserin; D011224:Prazosin