Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight
Abstract. This study was aimed at elucidating the possible effects of a large annual variation in photoperiodicity on the secretory activities of the pineal gland, pituitary and testes. Serum daytime melatonin, FSH, LH, prolactin (Prl), testosterone and oestradiol concentrations were determined mont...
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Oxford University Press (OUP)
1985
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Online Access: | http://dx.doi.org/10.1530/acta.0.1090446 https://eje.bioscientifica.com/view/journals/eje/109/4/acta_109_4_003.xml |
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croxfordunivpr:10.1530/acta.0.1090446 2024-10-06T13:51:29+00:00 Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight Martikainen, Hannu Tapanainen, Juha Vakkuri, Olli Leppäluoto, Juhani Huhtaniemi, Ilpo 1985 http://dx.doi.org/10.1530/acta.0.1090446 https://eje.bioscientifica.com/view/journals/eje/109/4/acta_109_4_003.xml unknown Oxford University Press (OUP) Acta Endocrinologica volume 109, issue 4, page 446-450 ISSN 0804-4643 1479-683X journal-article 1985 croxfordunivpr https://doi.org/10.1530/acta.0.1090446 2024-09-10T04:12:28Z Abstract. This study was aimed at elucidating the possible effects of a large annual variation in photoperiodicity on the secretory activities of the pineal gland, pituitary and testes. Serum daytime melatonin, FSH, LH, prolactin (Prl), testosterone and oestradiol concentrations were determined monthly over a year in 24 healthy young adult men (except for melatonin which was analysed only in 11 subjects) in northern Finland, where the day length is 22 h in mid-summer and 3.5 h in midwinter. Serum daytime melatonin levels showed two annual peak values, in December and May, and a nadir was observed in August. The absolute values of the other hormones measured did not show significant month to month variation over the observation period. When hormone levels were calculated as percentages of the individual annual means, several significant differences were found between monthly levels. The melatonin peak in May (133 ±20%, se , of the annual mean) was associated with significant increases in LH (110 ±4%) and FSH (107 ± 3%). Prl levels (115 ± 9%) reached a maximum in January. The nadirs of melatonin and the pituitary hormones measured were seen in August. Oestradiol showed the highest values in April-June, but no significant variation was found in serum testosterone levels. Positive correlations were observed between FSH and LH (r = 0.41, P <0.01), and Prl and LH (r = 0.26, P < 0.01), whereas Prl and testosterone (r = −0.17, P < 0.01) were inversely correlated. This study indicates circannual rhythmicity of peripheral serum daytime melatonin, gonadotrophin, Prl and oestradiol levels, but this variation was not related to extremes in daylight and therefore seasonal factors other than light may regulate this circannual variation. Article in Journal/Newspaper Northern Finland Oxford University Press Midwinter ENVELOPE(139.931,139.931,-66.690,-66.690) Acta Endocrinologica 109 4 446 450 |
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Open Polar |
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Oxford University Press |
op_collection_id |
croxfordunivpr |
language |
unknown |
description |
Abstract. This study was aimed at elucidating the possible effects of a large annual variation in photoperiodicity on the secretory activities of the pineal gland, pituitary and testes. Serum daytime melatonin, FSH, LH, prolactin (Prl), testosterone and oestradiol concentrations were determined monthly over a year in 24 healthy young adult men (except for melatonin which was analysed only in 11 subjects) in northern Finland, where the day length is 22 h in mid-summer and 3.5 h in midwinter. Serum daytime melatonin levels showed two annual peak values, in December and May, and a nadir was observed in August. The absolute values of the other hormones measured did not show significant month to month variation over the observation period. When hormone levels were calculated as percentages of the individual annual means, several significant differences were found between monthly levels. The melatonin peak in May (133 ±20%, se , of the annual mean) was associated with significant increases in LH (110 ±4%) and FSH (107 ± 3%). Prl levels (115 ± 9%) reached a maximum in January. The nadirs of melatonin and the pituitary hormones measured were seen in August. Oestradiol showed the highest values in April-June, but no significant variation was found in serum testosterone levels. Positive correlations were observed between FSH and LH (r = 0.41, P <0.01), and Prl and LH (r = 0.26, P < 0.01), whereas Prl and testosterone (r = −0.17, P < 0.01) were inversely correlated. This study indicates circannual rhythmicity of peripheral serum daytime melatonin, gonadotrophin, Prl and oestradiol levels, but this variation was not related to extremes in daylight and therefore seasonal factors other than light may regulate this circannual variation. |
format |
Article in Journal/Newspaper |
author |
Martikainen, Hannu Tapanainen, Juha Vakkuri, Olli Leppäluoto, Juhani Huhtaniemi, Ilpo |
spellingShingle |
Martikainen, Hannu Tapanainen, Juha Vakkuri, Olli Leppäluoto, Juhani Huhtaniemi, Ilpo Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
author_facet |
Martikainen, Hannu Tapanainen, Juha Vakkuri, Olli Leppäluoto, Juhani Huhtaniemi, Ilpo |
author_sort |
Martikainen, Hannu |
title |
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
title_short |
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
title_full |
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
title_fullStr |
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
title_full_unstemmed |
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
title_sort |
circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight |
publisher |
Oxford University Press (OUP) |
publishDate |
1985 |
url |
http://dx.doi.org/10.1530/acta.0.1090446 https://eje.bioscientifica.com/view/journals/eje/109/4/acta_109_4_003.xml |
long_lat |
ENVELOPE(139.931,139.931,-66.690,-66.690) |
geographic |
Midwinter |
geographic_facet |
Midwinter |
genre |
Northern Finland |
genre_facet |
Northern Finland |
op_source |
Acta Endocrinologica volume 109, issue 4, page 446-450 ISSN 0804-4643 1479-683X |
op_doi |
https://doi.org/10.1530/acta.0.1090446 |
container_title |
Acta Endocrinologica |
container_volume |
109 |
container_issue |
4 |
container_start_page |
446 |
op_container_end_page |
450 |
_version_ |
1812179703943921664 |