Activation of alpha1-adrenoceptors inhibits growth hormone secretion in humans.
In order to determine whether an alpha1-adrenergic mechanism is involved in the secretion of Growth Hormone (GH) in humans, we studied the effect of the alpha1-adrenergic-stimulating agent methoxamine on serum GH levels in twelve normal males (age range 22-32 years). Intravenous infusion of methoxamine (dose: 6 microg/kg/min; duration: 150 min) significantly reduced serum GH levels at time 120 and 150, and on integrated concentrations. These data suggest that alpha1-adrenergic receptors inhibit tonic GH secretion in humans.
Dipartimento-Struttura Clinica Medica-Patologia Speciale Medica, University of Sassari, Viale San Pietro 8, 07100 Sassari, Italy. gfanciu@uniss.it
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D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000328:Adult; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000502:physiology; D008297:Male; D008729:Methoxamine / Q000494:pharmacology*; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D018340:Receptors, Adrenergic, alpha-1; D013006:Growth Hormone; D008729:Methoxamine