The 5HT(7) receptor subtype is involved in the regulation of female sexual behaviour in the rat.
5-Hydroxytryptamine (5-HT) regulates sexual behaviour in the female rat via a number of its receptors. The role of the 5HT(7) receptor was investigated in ovariectomised rats primed with 10 mug oestradiol benzoate (OB) followed at 48 h by 0.5 mg progesterone, which induced receptivity in approximately half of the animals. These animals were treated with three agonists all effective at 5HT(1A) and 5HT(7) receptors; 5-hydroxytryptophan, 8-hydroxy-2-(di-n-propylamino)tetralin 1-Br (8-OH DPAT) and 5-carboxy-aminotryptamine (5-CT) in the presence or absence of selective 5HT(1A) and 5HT(7) antagonists: WAY 100135 and SB 269970-A. The three agonists inhibited lordosis in the receptive group, and this was prevented by both the selective 5HT(1A) and 5HT(7) antagonists. When given alone, both WAY 100135 and SB 269970-A increased the lordosis in the non-receptive rats indicating that endogenous 5-HT acting on 5HT(1A) and 5HT(7) receptors may have a tonic inhibitory effect on receptivity. A comparison of OB priming doses on the effect of serotoninergic agents showed that the higher OB doses attenuated the inhibitory effect of 8-OH DPAT and enhanced the stimulatory effect of WAY 100135, but did not affect the actions of 5-CT or SB 269970-A. The interaction between oestradiol and 5-HT activity on sexual behaviour may therefore be selective to the 5HT(1A) pathway.
Siddiqui
Arif
A
Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74800, Pakistan. arif.siddiqui@aku.edu
Niazi
Ambreen
A
Shaharyar
Saeeda
S
Wilson
Catherine A
CA
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D010052:Ovariectomy; D010879:Piperazines / Q000494:pharmacology; D011187:Posture; D051381:Rats; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D010879:Piperazines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C104425:serotonin 7 receptor; D044282:Receptor, Serotonin, 5-HT1A; C081293:WAY 100135; D012701:Serotonin; D004958:Estradiol; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C047087:5-carboxamidotryptamine