The influence of alpha-receptors on lordosis in the female rat.
The alpha-adrenergic agonist clonidine suppressed lordotic responding in spayed female rats brought into heat by estrogen and progesterone. The suppression was blocked by the alpha-antagonist yohimbine, but not by phenoxybenzamine or pimozide. The suppression was blocked by the alpha-antagonist yohimbine, but not by phenoxybenzamine or pimozide. Phenoxybenzamine itself had no suppressive effect on lordosis, though yohimbine did under some conditions. These results argue against an important facilitatory influence of norepinephrine on lordosis in the rat. Further, in comparison with the quite different findings recently reported from the guinea pig, they offer support for the presence of two different kinds of alpha-adrenergic receptors in the brain with different physiological functions.
D000818:Animals; D002369:Castration; D003000:Clonidine / Q000494:pharmacology; D004347:Drug Interactions; D005260:Female; D010643:Phenoxybenzamine / Q000494:pharmacology; D010868:Pimozide / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D010643:Phenoxybenzamine; D010868:Pimozide; D015016:Yohimbine; D003000:Clonidine