Obesity and precursor availability affect urinary catecholamine metabolite production in women

Abstract

The effect of obesity and tyrosine (tyr) supplements on catecholamine metabolism in 12 normal weight and nine obese adult women was studied. Protein intake was maintained at 1.4 g protein/kg fat-free mass daily for 4 days with tyr added (0.26 g/kg fat-free mass) to the liquid diet on the last 2 days. In the 12 normal subjects, but not the obese, base-line urinary excretion of the norepinephrine metabolite, 3-methoxy-4-hydroxy phenylethyleneglycol was related to body fat whereas excretion of the norepinephrine metabolite vanilmandelic acid was related to fat-free mass and to total energy intake. Normal subjects responded to tyr with elevations in plasma tyr/neutral amino acid, plasma 3-methoxy-4-hydroxy phenylethyleneglycol, urinary vanilmandelic acid, and homovanillic acid, a dopamine metabolite, but not the norepinephrine metabolite, dihydroxy phenylethyleneglycol. The obese showed no increase in plasma or urinary 3-methoxy-4-hydroxy phenylethyleneglycol during tyr supplementation, although vanilmandelic acid and homovanillic acid increased. We conclude that urinary catecholamine metabolite production is related to body composition and to tyr intake in normal weight women. These relationships however, are altered in the obese, suggesting an association of obesity with abnormal catecholamine metabolism.

Effect of a novel monamine oxidase‐a inhibitor, bw 1370U87, on urinary 3‐methoxy‐4‐hydroxyphenylglycol in normal volunteers

“…The 24 h urinary MHPG levels for the volunteers in this study are within the normal range reported in the literature [ Maes et al, 1989;Muscettola et al, 1984;Lensch et al, 1987;DeMet et al, 1985;Alonso et al, 1981;Dekirmenjian et al, 1970;Karege, 1984;Julien et al, 1988;Giedke et al, 1982;Wehr et al, 1980;Johnston et al, 1983 [ 19781 can be combined to make a direct comparison to the collection intervals in our study. Increases over the 0-4 h interval are more pronounced in our study (4-8 h, 33 vs. 9%; and 8-12 h, 59 vs. 30%) than in…”

Chronic dietary tyrosine supplements do not affect mild essential hypertension.

“…We therefore elected to allow our volunteers to maintain their usual dietary regimen and employed supplements of tyrosine calculated to approximately double their daily intake of this amino acid"; this was reflected by the twofold increase in tyrosine concentrations we observed in their plasma. A similar dietary program of supplemental tyrosine has been reported to maintain this relative increase for most of each 24-hour period 3 ' 15 and to enhance urinary excretion of metabolites of both norepinephrine and dopamine. 3 Brain tyrosine concentration reflects that in plasma.'…”

“…A similar dietary program of supplemental tyrosine has been reported to maintain this relative increase for most of each 24-hour period 3 ' 15 and to enhance urinary excretion of metabolites of both norepinephrine and dopamine. 3 Brain tyrosine concentration reflects that in plasma.' 6 -l7 Although this concentration appears to exceed the K m (25 /AM) for tyrosine hydroxylase, 18 the ratelimiting step for norepinephrine biosynthesis, studies have shown that an increase in brain tyrosine can lead to an increase in brain norepinephrine synthesis.…”

“…First, in one study in which quantities of tyrosine identical to those used in the present study were added to diets of normal weight women, both plasma levels and the 24-hour urinary excretion of 3 methoxy-4-hydroxyphenylglycol were increased. 3 There is good evidence that a proportion of this metabolite is of central origin.…”

Dietary flavonols contribute to false-positive elevation of homovanillic acid, a marker of catecholamine-secreting tumors

“…Certain drugs, e.g. L-dopa, are known to confound HVA estimation [10], as well as several dietary factors including vitamin B6 in combination with magnesium [11], nicotinamide adenine dinucleotide (NADH) used to treat patients with Parkinson's Disease [12], high monoamine meals in patients with Schizophrenia [13], and tyrosine supplementation in obese women [14]. These possible confounders are avoided prior to testing, under routine protocol.…”