Factors Influencing Urinary 6‐sulphatoxymelatonin, a Major Melatonin Metabolite, in Normal Human Subjects

Abstract

6-Sulphatoxymelatonin (aMT6s) has been measured, by a direct radioimmunoassay, in urine from 130 normal volunteers aged 2-80 years. Its relationship to a number of physiological parameters has been assessed. Total urinary excretion of aMT6s did not vary in a group of 40 children aged 2-20 years (24 boys and 16 girls) except when expressed as a function of body weight. In this case, total aMT6s excretion over 24 h decreased as a function of age. In 90 adult volunteers (44 men and 46 women) aged 20-80 years, there was an age-related decline in total 24 h aMT6s excretion with significantly lower values in elderly subjects. In this same adult group no relationships were found between total aMT6s excretion and body weight or height. No sex differences were found either in the 2-20 years or the 20-80 years groups. Pineal calcification was assessed by lateral skull X-ray in 26 adult volunteers (17 men and 9 women) aged 20-50 years. No significant differences in aMT6s excretion were found as a function of pineal calcification. In 16 of these subjects plasma melatonin and aMT6s also showed no relationship to pineal calcification. These studies confirm the usefulness of aMT6s as an index of melatonin secretion in normal volunteers.

Pineal volume and circadian melatonin profile in healthy volunteers: An interdisciplinary approach

“…In a postmortem study of 33 cases Schmid et al (32) did not find a correlation between calcium deposits in human pineal gland but a negative correlation between calcium supernatant and the nighttime melatonin of pineal glands. Bojkowski and Arendt (35) did not find a correlation between 6-sulfatoxymelatonin (the urinary excretional form of melatonin) and pineal calcifications as detected by lateral skull x-ray. Kunz et al (36) used a semiquantitative approach to analyze CT slices (4 mm thickness).…”

A New Concept for Melatonin Deficit On Pineal Calcification and Melatonin Excretion

“…Firstly, the size of pineal calcification is not associated with melatonin secretion (Bojkowski and Arendt 1990;Commentz et al 1986). This is in line with the lack of association between the size of pineal calcification and pathologies.…”

“…It is generally stated that no correlation can be demonstrated between the occurrence of pineal calcification and a reduced melatonin production (Arendt 1995). But, the two studies frequently cited in that context used predominantly skull X-ray, which provides only little information on the quantity of calcification-density and no information about the size of the remaining non-calcified tissue (Bojkowski and Arendt 1990; Commentz et al 1986).The adult shape and size of the pineal gland are, presumably genetically, determined early in life and reach their final stage around the first year of life (Wetterberg et al 1983;Schmidt et al 1995). The weight and dimensions are highly variable-up to a 20-fold inter-individual variance (Vollrath 1981;Hasegawa et al 1987;Bhatnagar 1990;Schmidt et al 1995).…”

“…It is generally stated that no correlation can be demonstrated between the occurrence of pineal calcification and a reduced melatonin production (Arendt 1995). But, the two studies frequently cited in that context used predominantly skull X-ray, which provides only little information on the quantity of calcification-density and no information about the size of the remaining non-calcified tissue (Bojkowski and Arendt 1990;Commentz et al 1986). …”

Male-female differences in 6-sulfatoxymelatonin excretion in hypopituitary patients

“…It is worth mentioning that melatonin has, in physiological conditions, a circadian secretory rhythm with low concentrations during daytime and high concentrations at night, with peak concentrations at approximately 0300 h (14). In previous studies, maximum pineal activity has been reported to occur in childhood and progressively decline in the following decades of life (14,15).…”