Abstract
MT extracted from 5 ml of plasma was bioassayed using its skin lightening effect on Xenopus laevis larvae. Less than 200 pg MT/ml of assay medium may be measured. 72.1 ± 1 % (mean ± SD) of added 3H-MT and 72.3 ± 9.5 % (mean ± SD) of unlabelled MT are recovered by extraction. Antibodies to MT have been raised in rabbits by conjugating N-acetyl-5-methoxy-tryptophan to bovine, serum albumin (BSA) and also thyroglobulin. Only the BSA antibody showed significant cross-reactions (N-acetyl-serotonin, 3.2 %, 6-hydroxy-MT, 4.6 %). The sensitivity range is similar to the bioassay. Dilution curves of plasma MT were parallel to the standard curve. Results were as follows (pg/ml) : 1) Bioassay : Obese children, 10-15 yrs, both sexes, 12 h = 119 ± 41, 24 h (artificial light) = 187 ± 43; adults, both sexes, 12 h = 177 ± 94, 24 h (artificial light) = 189 ± 51; male adults, 12 h = 147 ± 50, 24 h (obscurity 20-24 h) = 861 ± 514. 2) Radioimmunoassay : Male adults, 12 h = 445 ± 96, 24 h (obscurity 20-24 h) = 742 ± 156. Preliminary results seem to indicate that plasma MT levels found in obese children were not higher than those found in adults.
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Arendt, J., Paunier, L. & Sizonenko, P. ESTIMATION OF PLASMA MELATONIN (MT) CONCENTRATIONS IN CHILDREN AND ADULTS DURING THE LIGHT AND DARK PHASES OF THE DAY. Pediatr Res 9, 682 (1975). https://doi.org/10.1203/00006450-197508000-00093
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DOI: https://doi.org/10.1203/00006450-197508000-00093
