Annual changes in 6-sulphatoxymelatonin excretion in man
| Autor: | C. Bojkowski, Josephine Arendt |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
Adult
Male medicine.medical_specialty Endocrinology Diabetes and Metabolism Urinary system Urine Annual change Excretion Melatonin Endocrinology Animal science Internal medicine medicine Humans Circadian rhythm Melatonin secretion 6-sulphatoxymelatonin business.industry General Medicine Circadian Rhythm Female Seasons business medicine.drug |
| Zdroj: | Acta Endocrinologica. 117:470-476 |
| ISSN: | 1479-683X 0804-4643 |
| DOI: | 10.1530/acta.0.1170470 |
| Popis: | A recently developed RIA for 6-sulphatoxymelatonin, the major urinary metabolite of melatonin, has been used to investigate the annual change in melatonin secretion in humans. Twenty plasma samples were taken from 18 volunteers throughout a 24-h period and simultaneous 6-hourly urine samples were also collected. Plasma melatonin and urinary 6-sulphatoxymelatonin were measured by RIA. 6-Sulphatoxymelatonin assayed in the urine samples was shown to be a good index of the rhythmic characteristics of the plasma melatonin secretion. To study annual changes in excretion four sequential 6-hourly urine samples were collected at monthly intervals from 16 normal volunteers for 13 months. Cosinor curves were fitted to the 6-sulphatoxymelatonin excretion data and the 24-h rhythm was described by the cosinor parameters: amplitude, mesor and acrophase. Significant differences in the acrophase were found during the year. The summer acrophase was phase advanced relative to the winter acrophase by about 1.5 h while intermediate phase positions were observed in spring/autumn. The 24-h excretion of urinary 6-sulphatoxymelatonin was remarkably consistent and there was no annual rhythm. In contrast, the daytime 6-sulphatoxymelatonin excretion between 12.00–18.00 h showed a statistically significant seasonal rhythm, with peaks in December/January and in July. |
| Databáze: | OpenAIRE |
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