Progesterone attenuates the effect of the 5-HT1A receptor agonist, 8-OH-DPAT, and of mild restraint on lordosis behavior

Behavioural Brain Research

2015

Self Cite

Regularly cycling Fischer female rats were treated with either a low (5 mg/kg) or high (5 mg/RAT; approximately 30 mg/kg) dose of the antiprogestin, RU486, before the morning of proestrus or on the morning of proestrus. The emergence of sexual behavior after treatment with RU486 was examined in a mating test with a sexually active male rat. Lordosis behavior was remarkably resistant to the effects of RU486. Only the high dose of RU486 given the evening before proestrus, approximately 22 hours before mating, reduced lordosis behavior. Independent of dose or time of treatment, proceptivity was reduced and resistance to the male’s attempts to mount was increased by RU486 treatment. In addition, the effect of a 5 min restraint stress on sexual behavior was examined. In contrast to the relative resistance of lordosis behavior of unrestrained rats to RU486 treatment, RU486 treated rats showed a significant decline in lordosis behavior after restraint. These findings allow the suggestion that the emergence of lordosis behavior is relatively resistant to the antiprogestin while the maintenance of lordosis behavior after restraint may require participation of intracellular progesterone receptors.

Section: 0 Discussionmentioning

confidence: 99%

Dose-dependent effects of the antiprogestin, RU486, on sexual behavior of naturally cycling Fischer rats

Behavioural Brain Research

2015

Self Cite

“…In fact, virtually all aspects of 5-HT synthesis and metabolism are modified by estradiol (Bethea et al, 2002; Clark et al, 2012; Lu et al, 2003; Smith et al, 2004) and/or progesterone (Farmer et al, 1996; Maswood et al, 1995; Renner et al, 1987). Not surprisingly, therefore, the type and timing of hormonal treatment can have robust effects on the sexual behavioral response to 5-HT drugs (Guptarak et al, 2010; Jackson and Etgen, 2001; Jackson and Uphouse, 1998, 1996; Trevino et al, 1999; Truitt et al, 2003). …”

Section: 0 Summary and Conclusionmentioning

confidence: 99%

Pharmacology of serotonin and female sexual behavior

Pharmacology Biochemistry and Behavior

2014

Self Cite

In this review, first a historical perspective of serotonin’s (5-HT) involvement in female sexual behavior is presented. Then an overview of studies implicating 5-HT is presented. The effect of drugs that increase or decrease CNS levels of 5-HT is reviewed. Evidence is presented that drugs which increase 5-HT have negative effects on female sexual behavior while a decrease in 5-HT is associated with facilitation of sexual behavior. Studies with compounds that act on 5-HT1, 5-HT2 or 5-HT3 receptors are discussed. Most evidence indicates that 5-HT1A receptor agonists inhibit sexual behavior while 5-HT2 or 5-HT3 receptors may exert a positive influence. There is substantial evidence to support a role for 5-HT in the modulation of female consummatory sexual behavior, but studies on the role of 5-HT in other elements of female sexual behavior (e.g. desire, motivation, sexual appetite) are few. Future studies should be directed at determining if these additional components of female sexual behavior are also modulated by 5-HT.

“…Bilateral ovariectomy was performed immediately after implant surgery [37] and the rats were allowed to recover for at least 2 weeks. Dental acrylic was purchased from Reliance Dental Mfg Co (Worth, IL) and suture materials were obtained from Henry Schein (Melville, NY).…”

Section: Surgical Procedures-whenmentioning

confidence: 99%

“…When effects of BIM were examined, rats were preinfused with BIM or distilled/deionized water after the pretest but 30 or 90 min prior to infusion with the 5-HT receptor agonist(s). Sexual behavior after infusion with 5-HT receptor compounds was monitored for 30 consecutive min as previously described [37]. Sexual receptivity was quantified as the lordosis to mount (L/M) ratio (e.g.…”

Section: Behavioral Testing-mentioning

confidence: 99%

The PKC inhibitor, bisindolymaleimide, blocks DOI's attenuation of the effects of 8-OH-DPAT on female rat lordosis behavior

Selvamani

Lincoln

Behavioural Brain Research

2007

Self Cite

Ovariectomized rats with bilateral cannulae near the ventromedial nucleus of the hypothalamus were hormonally primed with 10μg estradiol benzoate and 500μg progesterone. Sexually receptive females were infused bilaterally with 200 ng of the 5-HT 1A receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), or with a combination of 200 ng 8-OH-DPAT and 2000 ng of the 5-HT 2 receptor agonist, (±)-2,5-dimethoxy-4-iodophenyl-2-aminopropane HCl (DOI). 8-OH-DPAT inhibited lordosis behavior and DOI reduced this inhibition. However, if females were preinfused with the PKC inhibitor, bisindolymaleimide I hydrochloride (BIM), DOI's effect was eliminated. BIM's attenuation of the effects of DOI was time-dependent. When BIM was infused 90 min, but not 30 min, before the 5-HT receptor agonists, BIM eliminated DOI's protection against the lordosisinhibiting effects of 8-OH-DPAT. A concentration of BIM as low as 10 −5 nmol in a 0.5μl infusion volume was effective and there was little evidence of dose responsivity between 10 −5 and 10 −1 nmol of BIM. In contrast, prior infusion with vehicle or with 10 −7 nmol BIM had no impact on the female's response to the 5-HT receptor agonists. These findings allow the suggestion that DOI's ability to increase PKC may be responsible for attenuation of the effects of 8-OH-DPAT on lordosis behavior. KeywordsPKC inhibitor; 5-HT 1A receptors; 5-HT 2 receptors; ovariectomized; sexual behavior IntroductionWithin the ventromedial nucleus of the hypothalamus (VMN), serotonin (5-HT) modulates female rat sexual behavior by acting on multiple 5-HT receptors [39]. Lordosis behavior, a supraspinal estrogen-dependent reflex of sexually receptive females [29], is inhibited by 5-HT 1A receptor agonists and facilitated by 5-HT 2 receptor agonists and their coactivation attenuates the lordosis-inhibitory effects of 5-HT 1A receptor agonists [39]. We have proposed that this 5-HT 1A /5-HT 2 receptor interaction enables the female to fine-tune her behavior so that it is most adaptive to environmental conditions [42]. However, the mechanisms for this interaction are not known.