title: Dexamethasone increases plasma HVA but not MHPG in normal humans.
abstract: Several recent studies in animals and man indicate that corticosteroids may alter catecholaminergic activity in both the peripheral and central nervous systems. We administered 1 mg of the synthetic glucocorticoid, dexamethasone, to 12 drug-free healthy volunteers and measured plasma homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG). Dexamethasone was administered at 11 p.m. and blood was collected at 4 p.m. on the preceding and subsequent days. Dexamethasone administration resulted in a significant increase in plasma HVA but did not consistently affect MHPG. All subjects showed a suppression of serum cortisol to values less than 5 micrograms/dl while prolactin levels were unaltered. In an additional group of nine volunteers, we administered 2 mg of dexamethasone and observed a similar increase in plasma HVA without change in plasma MHPG, indicating a selective effect on dopamine metabolism. Implications of these findings for an understanding of the neurochemical and behavioral changes seen with steroid administration and in explaining previous results on plasma MHPG/HVA ratios in delusional depression are discussed.
mesh_terms: D000328:Adult; D003907:Dexamethasone / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism; D005260:Female; D006018:Glycols / Q000097:blood*; D006719:Homovanillic Acid / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000097:blood*; D011388:Prolactin / Q000097:blood*
chemical_list: D006018:Glycols; D008734:Methoxyhydroxyphenylglycol; D003907:Dexamethasone; D011388:Prolactin; D004298:Dopamine; D006854:Hydrocortisone; D006719:Homovanillic Acid