title: Role of alpha-adrenergic mechanism in regulating tonic luteinizing hormone release in conscious ovariectomized rats.
abstract: The role of brain catecholamines in controlling tonic LH secretion was studied in unanesthesized, freely moving, ovariectomized rats. Pretreatment with reserpine (10 mg/kg), given 24 h before the experiment, significantly suppressed pulsatile LH secretion in these rats. Intraperitoneal administration of clonidine (1 mg/kg), an alpha-adrenergic stimulating agent, significantly raised plasma LH levels in reserpine-treated rats. On the other hand, the administration of apomorphine (1.5 mg/kg), a dopamine receptor-stimulating agent, had no effect on the plasma LH levels. These findings suggest an excitatory role of noradrenaline, operating through alpha-adrenergic receptors, in pulsatile LH secretion in ovariectomized rats.
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002369:Castration; D003000:Clonidine / Q000494:pharmacology; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D012110:Reserpine / Q000494:pharmacology*
chemical_list: D011942:Receptors, Adrenergic, alpha; D012110:Reserpine; D007986:Luteinizing Hormone; D003000:Clonidine; D001058:Apomorphine