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Adrenarche, androgens, and acclimation:Dehydroepiandrosterone-sulfate (DHEAS) and the primate life history

Hart, Emilee Nicole
http://orcid.org/0000-0001-7003-0617
http://rave.ohiolink.edu/etdc/view?acc_num=kent1720780661260643

Abstract Details

2024, PHD, Kent State University, College of Arts and Sciences / School of Biomedical Sciences.
In nonhuman primates, the adrenal gland serves an important function in the stress response and as an additional source of steroid hormones: estrogens and testosterone. Therefore, the measurement of these adrenal steroids can provide valuable information regarding the relationship between stress and reproductive fitness. This research documented the hormonal maturation of the adrenal gland in small apes and explored how environmental, reproductive, and social changes influence adrenal hormone secretions in primates. The first objective was to determine the presence and pattern of adrenarche in the small apes. This objective collected cross-sectional fecal samples from 64 (35F, 29M) zoo-housed small apes and longitudinal fecal samples from 7 female zoo-housed small apes and measured dehydroepiandrosterone-sulfate (DHEAS) by enzyme immunoassay to determine the pattern of hormone secretion characteristic of the activation of the adrenal gland, or adrenarche. This study tested the effects of age, sex, and genus on fecal DHEAS levels using generalized linear mixed-effects models (GLMM). The results showed that age was positively correlated with a pre-pubertal increase in fecal DHEAS across all genera in the study (Hylobates spp., Hoolock spp., Nomascus spp., Symphalangus syndactylus) indicating that the small apes exhibit delayed adrenarche similar to the great apes. The second objective was to examine how reproductive state and social dominance impact fecal androgens and the glucocorticoid metabolite (GCM) to DHEAS ratio (GCM:DHEAS) in free-ranging Japanese macaques (Macaca fuscata) considering environmental factors (season and ambient temperature) and social behaviors (i.e., aggression, and affiliation) as potential variables influencing these steroid hormones. This objective measured fecal GCM and DHEAS in 354 samples by enzyme immunoassay in 11 female macaques (7 pregnant/lactating, 4 nonpregnant/nonlactating). Using GLMM, the results showed that pregnant and lactating female macaques had significantly higher fecal DHEAS levels than nonpregnant/nonlactating females. Additionally, the results revealed that dominant females in this population had higher fecal DHEAS levels and lower GCM:DHEAS levels than subordinate females. This suggests that the greater fecal DHEAS levels in high-ranking females could explain their high reproductive fitness despite their elevated GCM levels. The third objective was to measure the adrenal response using fecal GCM and DHEAS in northern white-cheeked gibbons (Nomascus leucogenys) to two stressful events: 1) acclimation to a new exhibit and 2) the death of a group member. Both studies highlighted individual differences in the acclimation process indicating that behavioral signals of stress did not consistently correspond to physiological markers of stress. Therefore, the integration of fecal GCM and DHEAS measurements in behavioral studies can provide valuable information to interpret individual stress levels to acute and chronic stress events. Together, these three objectives aimed to identify the role of DHEAS in primate life history in addition to different extrinsic and intrinsic factors that may impact the levels. Overall, the knowledge gathered through this research will provide explanations for variations in DHEAS secretions observed in past and future studies on nonhuman primates and humans.
Rafaela Takeshita (Advisor)
Richard Meindl (Committee Member)
Mary Ann Raghanti (Committee Member)
Wilson Chung (Committee Member)
128 p.
Animals; Behavioral Sciences; Biology; Developmental Biology; Ecology; Endocrinology; Evolution and Development; Physiology; Social Structure; Welfare; Zoology
adrenal steroids; adrenarche; small apes; gibbons; DHEAS; fecal steroids; glucocorticoids; Japanese macaques; nonhuman primates; dominance; reproductive state; season; stress; acclimation; zoo welfare; death response

Recommended Citations

Citations

  • Hart, E. N. (2024). Adrenarche, androgens, and acclimation:Dehydroepiandrosterone-sulfate (DHEAS) and the primate life history [Doctoral dissertation, Kent State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=kent1720780661260643

    APA Style (7th edition)

  • Hart, Emilee. Adrenarche, androgens, and acclimation:Dehydroepiandrosterone-sulfate (DHEAS) and the primate life history. 2024. Kent State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=kent1720780661260643.

    MLA Style (8th edition)

  • Hart, Emilee. "Adrenarche, androgens, and acclimation:Dehydroepiandrosterone-sulfate (DHEAS) and the primate life history." Doctoral dissertation, Kent State University, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=kent1720780661260643

    Chicago Manual of Style (17th edition)

kent1720780661260643
79
© 2024, some rights reserved.Creative Commons License Adrenarche, androgens, and acclimation:Dehydroepiandrosterone-sulfate (DHEAS) and the primate life history by Emilee Nicole Hart is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Kent State University and OhioLINK.