Central and peripheral metabolites of norepinephrine and dopamine in postmenopausal women

Urinary 3-methoxy-4-hydroxyphenylglycol (MHPG) sulfate and glucuronide reflect, in part, central norepinephrine activity while urinary 3-methoxy-4-hydroxymandelic (VMA) reflects peripheral norepinephrine activity. Urinary MHPG and VMA were measured, together with homovanillic acid (HVA), in 20 symptomatic and seven asymptomatic postmenopausal women and 10 premenopausal control women. Urinary HVA reflects, in part, central dopamine metabolism. After nine of the symptomatic women were treated for 2 months with 0.625 mg of conjugated estrogens, urinary catecholamine measurements were repeated. Serum estrogen levels were not different in symptomatic and asymptomatic patients. Urinary MHPG, VMA, and HVA were similar in symptomatic women before and after estrogen treatment and were not different from levels of asymptomatic postmenopausal and control subjects. The ratios of MHPG:VMA, MHPG:HVA, and VMA:HVA also were similar. While body weight and estrogen did not correlate with urinary catecholamines, there was a significant positive correlation between MHPG and age in postmenopausal subjects (r = 0.56, p less than 0.005).