title: Possible role of alpha-2-noradrenergic receptors in modulation of sexual behavior in female guinea pigs.
abstract: These studies examine whether alpha 1-noradrenergic receptor stimulation alone is sufficient to facilitate lordosis behavior in ovariectomized, estrogen-primed female guinea pigs and to what extent alpha 2-noradrenergic receptors are involved in this steroid-dependent behavior. Neither of the alpha 1-agonists, phenylephrine or methoxamine, significantly facilitated lordosis in ovariectomized females primed with 10 micrograms of estradiol benzoate for 1 or 3 days. Animals exhibiting estrogen plus clonidine-facilitated lordosis showed a decrease in the behavior when given one of two alpha 2-antagonists (yohimbine or idazoxan). Idazoxan also attenuated lordosis in animals given estrogen plus progesterone. These findings, in combination with previous findings (that specific alpha 1-antagonists block lordosis), suggest that alpha 2-receptors, in addition to alpha 1-receptors play a role in modulation of lordosis behavior.
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D004958:Estradiol / Q000502:physiology; D005260:Female; D006168:Guinea Pigs; D019329:Idazoxan; D008729:Methoxamine / Q000494:pharmacology; D010052:Ovariectomy; D010656:Phenylephrine / Q000494:pharmacology; D011187:Posture; D011374:Progesterone / Q000502:physiology; D011942:Receptors, Adrenergic, alpha / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D011942:Receptors, Adrenergic, alpha; D010656:Phenylephrine; D015016:Yohimbine; D011374:Progesterone; D004958:Estradiol; D008729:Methoxamine; D003000:Clonidine; D019329:Idazoxan