Evidence for a role of alpha-adrenergic mechanisms in regulation of episodic growth hormone secretion in the rat.
The role of catecholamines in regulation of episodic GH secretion was investigated in the male rat. Administration of alpha-methyl-p-tyrosine (alpha-MT; 250 mg/kg ip) caused significant suppression of GH bursts and resulted in marked elevation of plasma PRL. Intravenous administration of apomorphine (.03 and .1 mg/kg) had no effect on decreased GH levels, whereas clonidine (150 micrograms/kg) restored GH secretion. Apomorphine significantly reduced PRL levels in alpha-MT-treated rats whereas, clonidine resulted in a further increase in PRL.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D013006:Growth Hormone / Q000378:metabolism*; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D010507:Periodicity; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*
D008781:Methyltyrosines; D011942:Receptors, Adrenergic, alpha; D011388:Prolactin; D013006:Growth Hormone; D003000:Clonidine; D001058:Apomorphine