alpha 1-adrenergic receptor involvement in the LH surge in ovariectomized estrogen-primed rats.
The circadian pattern of LH release observed in ovariectomized estrogen-implanted rats was inhibited by blockade of alpha-adrenergic receptors by phenoxybenzamine; in contrast, blockade of beta-receptors by propranolol was ineffective. Prasozin, an alpha 1-antagonist, was as effective as phenoxybenzamine, whereas yohimbine, an alpha 2-antagonist, was effective only at high doses. Neither phenoxybenzamine nor prazosin were able to modify the LHRH-induced release of LH from superfused pituitaries. These results suggest an involvement of hypothalamic alpha 1-receptors in the control of circadian LH release.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002369:Castration; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000378:metabolism*; D010902:Pituitary Gland / Q000378:metabolism; D011301:Preoptic Area / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000502:physiology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D004967:Estrogens; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone