Circatrigintan Cycle of Salivary Testosterone in Human Male

Celec, Peter; Ostatníková, Daniela; Putz, Z; Hodosy, Július; Burský, Peter; Stárka, L.; Hampl, Richard; Kúdela, Matúš

doi:10.1076/brhm.34.3.305.18807

Cited by 24 publications

(21 citation statements)

References 24 publications

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“…Salivary estradiol (E), progesterone (P) and testosterone (T) levels were determined by radioimmunoassay as described previously [4]. The intra-assay coefficient of variation is under 5% (on average 3.6%).…”

Section: Methodsmentioning

confidence: 99%

Salivary Sex Hormones during the Menstrual Cycle

et al. 2009

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Section: Methodsmentioning

confidence: 99%

Salivary Sex Hormones during the Menstrual Cycle

et al. 2009

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“…Levels of DHEA peak at Ϸ20 years of age and then decline to reach values of 20-30% at 70-80 years of age (1). Significant interest has arisen from the hypothesis that declining DHEA concentrations in adults may serve as an indicator of a number of conditions including the loss of insulin sensitivity, obesity, diabetes, cardiovascular diseases, stress, and aging (2). In clinical studies, DHEA levels were found to decline in mental illnesses such as major depressive disorder or in systematic diseases that respond to DHEA supplementation (3,4).…”

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confidence: 99%

Mitotic and neurogenic effects of dehydroepiandrosterone (DHEA) on human neural stem cell cultures derived from the fetal cortex

Suzuki

Wright

Marwah

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

143

136

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Dehydroepiandrosterone (DHEA) is a neurosteroid with potential effects on neurogenesis and neuronal survival in humans. However, most studies on DHEA have been performed in rodents, and there is little direct evidence for biological effects on the human nervous system. Furthermore, the mechanism of its action is unknown. Here, we show that DHEA significantly increased the growth rates of human neural stem cells derived from the fetal cortex and grown with both epidermal growth factor (EGF) and leukemia inhibitory factor (LIF). However, it had no effect on cultures grown in either factor alone, suggesting a specific action on the EGF͞LIF-responsive cell. Precursors of DHEA such as pregnenolone or six of its major metabolites, had no significant effect on proliferation rates. DHEA did not alter the small number (<3%) of newly formed neuroblasts or the large number (>95%) of nestin-positive precursors. However, the number of glial fibrillary acidic protein-positive cells, its mRNA, and protein were significantly increased by DHEA. We found both N-methyl-D-aspartate and sigma 1 antagonists, but not GABA antagonists, could completely eliminate the effects of DHEA on stem cell proliferation. Finally we asked whether the EGF͞LIF͞DHEA-responsive stem cells had an increased potential for neurogenesis and found a 29% increase in neuronal production when compared to cultures grown in EGF͞LIF alone. Together these data suggest that DHEA is involved in the maintenance and division of human neural stem cells. Given the wide availability of this neurosteroid, this finding has important implications for future use.

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“…Best described are the circadian and circannual rhythms with amplitudes in the morning and in autumn, respectively (Ostatnikova et al testosterone are also high during the ovulation phase of the menstrual cycle (Dabbs and de La 1991). A similar circalunar cycle of testosterone has been described in men (Celec et al 2003).…”

Section: Introductionmentioning

confidence: 78%

“…Blood contamination was checked visually before analysis. Salivary TST levels were determined by radioimunoassay as described previously (Celec et al 2003;Putz et al 1983). The sensitivity of the assay was 1 pg, interassay coefficient of variation 8,2% and intraassay coefficient of variation under 5%.…”

Section: Methodsmentioning

confidence: 99%

Lack of evidence for meteorological effects on infradian dynamics of testosterone

et al. 2009

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Climatic factors are known to influence the endocrine system. Previous studies have shown that circannual seasonal variations of testosterone might be partly explained by changes in air temperature. Whether infradian variations are affected by meteorological factors is unknown. To analyze possible effects of meteorological parameters on infradian variations of salivary testosterone levels in both sexes, daily salivary testosterone levels were measured during 1 month in 14 men and 17 women. A correlation analysis between hormonal levels and selected meteorological parameters was performed. The results indicate that high testosterone levels are loosely associated with cold, sunny and dry weather in both sexes. However, only the correlations between testosterone and air temperature (men) and actual cloudiness (women) were statistically significant (p < 0,05). Although some correlations reached the level of statistical significance, the effects of selected meteorological parameters on salivary testosterone levels remain unclear. Further longer-term studies concentrating on air temperature, cloudiness and average relative humidity in relation to the sex hormone axis are needed.

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Circatrigintan Cycle of Salivary Testosterone in Human Male

Cited by 24 publications

References 24 publications

Salivary Sex Hormones during the Menstrual Cycle

Salivary Sex Hormones during the Menstrual Cycle

Mitotic and neurogenic effects of dehydroepiandrosterone (DHEA) on human neural stem cell cultures derived from the fetal cortex

Lack of evidence for meteorological effects on infradian dynamics of testosterone

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