Menopause in Nonhuman Primates: A Comparative Study with Humans

Abstract

Although menopause is a phenomenon predominantly studied in humans or laboratory animals, this chapter discussed the case of nonhuman primates (NHPs), not only with the objective of employing them as study models but also to better understand phylogenetic divergence among species. Those taxonomic differences are reflected in reproductive processes that may be similar to those of human beings, with the presence of a defined cycle or periods of estrus, but perhaps at different ages as well, where menopause plays a crucial role. First, it is important to delimit the concept of menopause by considering its anatomical, physiological, and biochemical parameters, including the cessation of menstrual bleeding or perineal swelling-when present-or follicular depletion and hormonal changes. Thus, the aim of this chapter is to discuss some of the similarities between NHPs and human females, during the menopause period. Studying these phenomena should help us achieve a better understanding of the social, physiological, and environmental factors without adopting any particular cultural view of menopause.

Stable isotope evidence (Fe, Cu) suggests that sex, but not aging is recorded in rhesus macaque (Macaca mulatta) bone

“…Following the first proposed reason for sex differences, we predict that since rhesus macaques have a similar hormonal cycle and menstruation (~7 mL: Brenner & Slayden, 2012) to human females (de Jesús Rovirosa‐Hernández et al, 2017; Lewis & Prongay, 2015), the variation in Fe and Cu isotopic compositions in bone and teeth should reflect that of humans. We predict that based on human dental enamel and the short residence time of Cu in the body, there will be no sex differences in enamel δ 65 Cu values (Jaouen et al, 2017).…”

“…We examine the variation of δ 56 Fe and δ 65 Cu values in the bone and incisors of rhesus macaques ( Macaca mulatta ) with documented life histories to test for sex and age‐class differences characteristic of humans. Rhesus macaques ( Macaca mulatta ) were selected, because as old‐world monkeys, they exhibit menstrual cycles that range from 25 to 35 days with on average 7 mL blood loss, where ~1.1% of total blood volume is lost during menstruation, which is comparable to human females (~1.2%, Brenner & Slayden, 2012; de Jesús Rovirosa‐Hernández et al, 2017; Lewis & Prongay, 2015; Sharma & Sharma, 2018; Wolfensohn & Lloyd, 2008). Likewise, rhesus macaques are established non‐human primate models for studying Fe deprivation and are known to assimilate dietary Fe in a manner similar to humans (Giulietti et al, 1991; Golub & Hogrefe, 2014; Rao, Prasad, & Sarathy, 1977).…”

Longitudinal Effects of Immediate and Delayed Estradiol on Cognitive Performance in a Spatial Maze and Hippocampal Volume in Menopausal Macaques Under an Obesogenic Diet

“…Specifically, for work on reproductive senescence, NHPs provide several advantages over rodents as model animals. In both NHPs and humans, reproductive senescence in driven by the depletion of the follicular pool (18,19). In contrast, rodent reproductive senescence is driven by dysregulation of the hypothalamic-pituitary-ovarian (HPO) axis, resulting in mature viable follicles that are present throughout the lifespan (4).…”