Attenuation of the lordosis-inhibiting effects of 8-OH-DPAT by TFMPP and quipazine.
Regularly cycling, proestrous female rats received infusions of 200 ng of the serotonin (5-HT) 1A receptor agonist, (+/-) 8-hydroxy 2-(di-n-propylamino) tetralin-HBr (8-OH-DPAT), or 200 ng 8-OH-DPAT and 1000 or 2000 ng of N-(3-trifluoro-methylphenyl) piperazine hydrochloride (TFMPP) or 2-(1-piperazinyl) quinoline dimaleate (quipazine). Infusions were made bilaterally into the ventromedial nucleus of the hypothalamus (VMN). Animals receiving 200 ng 8-OH-DPAT exhibited a decline in lordosis behavior following infusion. Rats receiving 8-OH-DPAT and 1000 or 2000 ng quipazine or TFMPP were protected from the lordosis-inhibiting effects of 8-OH-DPAT, alone. Although both quipazine and TFMPP act on multiple 5-HT receptors, they overlap in their agonist action at 5-HT2 receptors. Consequently, these results provide further evidence supporting the contention that within the VMN, both 5-HT1A and 5-HT2 receptor subtypes contribute to the modulation of lordosis behavior in the female rat. The data are discussed in terms of the relative potency of 5-HT at 5-HT receptors mediating inhibition and facilitation of lordosis behavior.
Department of Biology, Texas Woman's University, Denton, TX 76204, USA.
A
A
Wolf
A
A
Jackson
T
T
Price
A
A
Trevino
M
M
Caldarola-Pastuszka
L
L
Uphouse
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D000818:Animals; D004971:Estrus / Q000502:physiology; D005260:Female; D010879:Piperazines / Q000494:pharmacology*; D011187:Posture / Q000502:physiology; D011814:Quipazine / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D010879:Piperazines; D017366:Serotonin Receptor Agonists; C018406:1-(3-trifluoromethylphenyl)piperazine; D011814:Quipazine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin