Phylogenetic influences on hormone levels across the primate order

Abstract

Adrenal and gonadal hormone levels were evaluated in representative species from F'rosimii, Ceboidea, Cercopithecoidea, and Hominoidea to determine if endocrine activity was influenced by phylogenetic factors. Most small-bodied New World primates had extremely high levels of cortisol, progesterone, and testosterone when compared with Old World primates. In contrast to the high hormone levels and diversity found in Ceboidea, Old World primates showed a more similar pattern of hormone secretion. Thus, this survey supports earlier reports indicating that the callitricids and smaller cebid monkeys have a distinctive hormone profile. Although higher hormone levels tended to be associated with lower body weight, this effect was not evident in all taxa, and there were many notable exceptions. When species differ from their predicted hormone levels based on phylogenetic heritage and body weight (e.g., titi monkeys), we must look for other biological factors that influence endocrine activity.

Saliva sampling to assess cortisol levels in unrestrained common marmosets and the effect of behavioral stress

“…These levels of free cortisol compare favorably with those found in the saliva of squirrel monkeys by Tiefenbacher et al [2003] (i.e., B500-600 nmoles per liter, depending on the time of day). Previous studies have found that the plasma cortisol levels of New World primates are 3-15 times higher than those of Old World primates, including humans [Coe et al, 1992]. One study reported the saliva cortisol level to be 34 nmol/l in rhesus macaques [Boyce et al, 1995], and judging by this, our results are in the region of 13-fold higher, as expected.…”

Social and reproductive influences on plasma cortisol in female marmoset monkeys

“…As found in previous studies of marmosets and other New World monkeys (12,17,64), plasma cortisol values were approximately 5-10 times higher than those of Old World primates, including humans. Basal plasma cortisol concentrations of females housed in heterosexual pairs averaged 214.1 __-21.5 and 171.7 ---17.0 #g/dl at 0900 and 1145 h, respectively.…”

Diurnal variation on the excretion patterns of fecal steroids in common marmoset ( Callithrix jacchus ) females

“…The highest plasma cortisol levels were registered at 0400, and the lower values were between the late afternoon and midnight. Besides the differences in the endocrine physiology in New World primates and the distinct range of variation for cortisol in the living Old and New World primates [Coe et al, 1992], a similar pattern of diurnal variation for this hormone appears to occur in different species of animals [Krieger, 1978]. Regarding this data, we should expect that diurnal secretion patterns for cortisol in marmosets would be comparable to those registered for the other primates.…”