Acute effects of medetomidine, a selective alpha 2-adrenoceptor agonist, on anterior pituitary hormone and cortisol secretion in man.
Single iv doses (25, 50 and 100 micrograms) of medetomidine, a selective alpha 2-adrenoceptor agonist of the imidazole type, were administered to 8 healthy male volunteers in a randomized, double-blind, placebo-controlled study. The concentration of hGH in plasma was powerfully and dose-dependently increased. The plasma level of cortisol was dose-dependently decreased, whereas TSH showed a slight but statistically significant increase. Plasma levels of PRL, FSH and LH were unaffected by the drug. Medetomidine appears to resemble other alpha 2-adrenoceptor agonists, notably clonidine, in its endocrine effects. Its high selectivity and short duration of action make it a suitable tool for studies of the physiology and pharmacology of alpha 2-adrenoceptors in man.
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage*; D000328:Adult; D002986:Clinical Trials as Topic; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005640:Follicle Stimulating Hormone / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007093:Imidazoles / Q000008:administration & dosage*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D020926:Medetomidine; D010908:Pituitary Hormones, Anterior / Q000097:blood / Q000378:metabolism*; D011388:Prolactin / Q000097:blood; D011897:Random Allocation; D013972:Thyrotropin / Q000097:blood
D000316:Adrenergic alpha-Agonists; D007093:Imidazoles; D010908:Pituitary Hormones, Anterior; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone; D020926:Medetomidine; D006854:Hydrocortisone