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 < 5 μg/d1 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.
- 3-methoxy-4- hydroxyphenylglycol
- homovanillic acid