Gender and Age Differences in the Growth Hormone Response to Pyridostigmine

Jv, Lucey; O'Keane,; O’Flynn, Karen; Aw, Clare; Tg, Dinan

doi:10.1097/00004850-199100620-00005

Cited by 18 publications

(11 citation statements)

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“…Gender and age differences in hormone parameters have already been described (Touitou et al 1982(Touitou et al , 1983Lucey et al 1991). DHEA is one of these, and is involved in maturing and aging processes.…”

Section: Discussionmentioning

confidence: 95%

Age and sex differences of dehydroepiandrosterone sulfate (DHEAS) and cortisol (CRT) plasma levels in normal controls and Alzheimer's disease (AD)

et al. 1993

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In 50 healthy subjects (23 female, 27 male, aged 18-81) and 24 patients with Alzheimer's disease (AD) (11 female, 13 male, aged 58-88) DHEAS and CRT plasma levels were studied. In normal subjects there was a clear negative correlation of DHEAS to age, while no significant age correlated decrease of CRT plasma levels was found. There was a significant decrease in the DHEAS/CRT ratio in elderly controls (aged > 60) as compared to young individuals (aged < 45). Overall there was a trend to lower DHEAS/CRT ratios in AD patients compared to age matched controls out of the total group of normals (P < 0.1), there was a significant decrease of this ratio in female AD patients (P < 0.05), compared to age matched female controls, but there was none in male Alzheimers; furthermore there was a significant difference in CRT plasma levels between female AD patients and age matched female controls (P < 0.01) and between female and male AD patients (P < 0.05). Considering the antiglucocorticoid effects of DHEAS, this ratio may account for its protective effect against hippocampal degeneration caused by glucocorticoids and possibly for the higher rate of AD in females.

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Section: Discussionmentioning

confidence: 95%

Age and sex differences of dehydroepiandrosterone sulfate (DHEAS) and cortisol (CRT) plasma levels in normal controls and Alzheimer's disease (AD)

et al. 1993

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“…Buffet et al, 2001) have verified that the concentrations and ratios of circulating sex hormones oscillate throughout the menstrual cycle and influence the central nervous system (CNS) in a large number of varied ways the menstrual cycle effects reported here may be related to hormonal influences. Cholinergic (Gibbs et al, 1998;Lucey et al, 1991;Tseng et al, 1997), glutamatergic (Gazzaley et al, 1996 andWoolley et al, 1997), GABAergic (Murphy et al, 1998), serotonergic (Biegon et al, 1983;Moses et al, 2000;Pecins-Thompson et al, 1996;Sumner and Fink, 1997) noradrenergic (Tseng et al, 1997), and dopaminergic neurotransmitter (Pasqualini et al, 1995) and (Pasqualini et al, 1996) systems all respond to sex hormones. Dopamine is of particular interest here given its role in both response inhibition (Hester et al, 2004) and the ACC error response (Holroyd and Coles, 2002).…”

Section: Discussionmentioning

confidence: 99%

Menstrual cycle phase modulates cognitive control over male but not female stimuli

et al. 2008

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Evolutionary selection pressures have been one of the factors proposed to underlie sex differences in inhibitory control. Consequently, inhibitory control may vary as a function of the menstrual cycle and may be modulated by the stimuli being processed if these stimuli are related to reproductive success. We used functional MRI to study women's brain activation across the menstrual cycle on a GO/NOGO response inhibition task using attractive male and female faces as stimuli. We detected brain activity changes for both successful inhibitions and errors of commission that were unique to the male stimuli during the follicular phase of the menstrual cycle. That is, when pregnancy was possible women had superior inhibitory brain function and heightened detection of inhibitory failures when processing male stimuli. Moreover, we show that individual differences between females in sexual desire and social risk taking negatively correlate with error-related brain activity to the male stimuli during the follicular phase of the menstrual cycle. These results suggest an interaction between hormonal influences and stimulus-specific effects in producing an endophenotypic outcome predicted by evolutionary psychology, and suggest that the functioning of the brain's monitoring system can predict individual differences in both traits and real-world risk-taking behaviours.© 2008 Elsevier B.V. All rights reserved. Keywords:Menstrual cycle Attractiveness Inhibition fMRI IntroductionParental investment theory (Trivers, 1972) postulates that many psychological differences between the sexes derive from different evolutionary pressures particular to the investment of resources in finding a mate vs. parenting. Theorists (Bjorkund and Kipp, 1996) have proposed that the greater parenting demands placed on females and the advantage of forming stable bonds with males, confer a selection advantage on those females with the ability to suppress sexual interests in other males or aggressive tendencies towards one's own offspring. Consequently, greater selection pressures on female ancestors

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“…As indicated in the Introduction, there are only a few prior cholinergic challenge studies that considered women and men separately, to which we can compare our GH fi ndings [12,13,19] . In these studies, PYRIDO was administered orally and at fi xed doses rather than based on Table 2.…”

Section: Discussionmentioning

confidence: 99%

“…Lucey et al [12] found a greater GH response to PYRIDO (120 mg) in pre-and postmenopausal women aged 19-58 years compared to men aged 19-56 years, with a significant positive correlation between serum estradiol and GH response in the women. Van Amelsvoort et al [13] found a signifi cantly greater GH response to PYRIDO (120 mg) in postmenopausal women on long-term estrogen replacement compared to postmenopausal women who were estrogen-naïve.…”

Section: Introductionmentioning

confidence: 97%

“…Decreased GH responses to pyridostigmine (PYRIDO) have been reported in elderly vs. young women and in non-estrogen-replaced postmenopausal women vs. those receiving hormone replacement therapy [12,13] . In contrast, increased hypothalamo-pituitary-adrenal cortical (HPA) responses to physostigmine (PHYSO) have been reported in elderly vs. young subjects and in elderly women vs. elderly men [14][15][16] .…”

Section: Introductionmentioning

confidence: 99%

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Growth Hormone Responses to Low-Dose Physostigmine in Elderly vs. Young Women and Men

Rubín

Miller²,

Rhodes³

et al. 2006

Gerontology

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Background: Growth hormone (GH) secretion is a sensitive measure of CNS cholinergic neurotransmission, and GH decreases considerably with age. Cholinesterase inhibitors, which increase acetylcholine concentrations, have been used in elderly subjects to investigate the neuroendocrine effects of aging and Alzheimer’s disease. However, there have been only a few studies of a potential sex difference in GH responses to cholinesterase inhibitors in elderly subjects, with mixed results. Objective: We therefore administered low-dose physostigmine (PHYSO), a cholinesterase inhibitor, to normal, non-hormone-replaced, elderly women and men, to ascertain a potential sex difference in GH response. We hypothesized: (1) elderly women and men would have similar hormone responses, because of relatively low circulating estrogen in the women, and (2) the elderly women would have significantly lower baseline GH and GH responses to cholinergic challenge than the young women we studied previously. Methods: Normal elderly women and men ≧65 years of age meeting stringent inclusion and exclusion criteria were studied on three test days, 4–7 days apart, by serial blood sampling for several hours for baseline GH, followed by administration of low-dose PHYSO (first and third days) or saline (second day) at 18:00 h. Frequent blood sampling was continued for several hours. Plasma GH and hypothalamo-pituitary-adrenal cortical hormones were measured in each sample. Results: PHYSO administration produced no side effects in about half the elderly subjects and mild side effects in the other half, with no significant female-male differences and no significant relationship between the presence or absence of side effects and GH response. PHYSO significantly increased GH compared to saline, to a similar degree in the elderly women and men. The elderly women had a significantly greater GH response to PHYSO than did the young women, whereas GH responses were similar in the elderly and young men. Conclusions: These results indicate similar GH responses to low-dose PHYSO in elderly women compared to elderly men, and a significantly greater GH response in elderly women compared to young women. A likely mechanism is increased sensitivity of central cholinergic systems that inhibit somatostatin and/or enhance GHRH release from the hypothalamus.

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Gender and Age Differences in the Growth Hormone Response to Pyridostigmine

Cited by 18 publications

References 0 publications

Age and sex differences of dehydroepiandrosterone sulfate (DHEAS) and cortisol (CRT) plasma levels in normal controls and Alzheimer's disease (AD)

Age and sex differences of dehydroepiandrosterone sulfate (DHEAS) and cortisol (CRT) plasma levels in normal controls and Alzheimer's disease (AD)

Menstrual cycle phase modulates cognitive control over male but not female stimuli

Growth Hormone Responses to Low-Dose Physostigmine in Elderly vs. Young Women and Men

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