A study was made in 2 consecutive years of the emotional states and morning and afternoon serum levels of prolactin, cortisol and testosterone of male medical students during a 4- to 5-week period preceding a major university examination. 'Distress', 'anxiety' and, to a lesser degree, 'depression' increased during the 2 weeks immediately preceding the examination and were positively correlated with personality anxiety or neuroticism traits. Group means for hormones showed no consistent change over the same period. Neither was there evidence for a correlation between endocrine and emotional changes within individual students during the pre-examination period. A restricted study showed that there were significant increments in cortisol in samples taken during the examination itself. Changes in emotional state before an examination occurred in the absence of equally dramatic changes in levels of the three hormones studied, though this relationship may have altered during the examination itself. This suggests that the factors controlling the two categories of response may relate differently, in some way, to the imminence of this stressful event.
Serum testosterone and androstenedione levels were lower in the subordinate female talapoin monkeys of four social groups than either dominant or intermediate-ranking females. This was found in both intact or ovariectomized (oestrogen-treated) animals, which suggests that androgen from the adrenals contributed to this rank-related endocrine effect. These differences disappeared when the females were housed singly, levels in all animals becoming similar to those in subordinates in the group cage. There were no rank-related differences in progesterone levels during either the follicular or luteal phase of the cycle in intact females, or in those of ovariectomized females of different rank, but cortisol was highest in dominant group-living animals in these experiments. Significant correlations were found between androgen levels in group-living females and the amount of sexual interest shown in them by males; the amount of aggressive interaction involving each female did not correlate with her androgen levels. Social rank is defined according to the direction, not the amount, of aggression. These findings suggest that the social hierarchy regulates androgen levels in these female monkeys; there may also be effects on the ability of females to respond to their own, or to administered, androgen. Similar findings have been made previously in male talapoins. Since androgens fill a critical role in the sexual behaviour of both sexes in primates, this may be a neuroendocrine mechanism of general significance relating behaviour to social rank.
Seven castrated monkeys were given either 50 or 100 micrograms 5 alpha-dihydrotestosterone (DHT) propionate/kg per day. There was no correlation between serum and cerebrospinal fluid (CSF) levels of DHT, which remained very low in the CSF (0.3-0.6% of blood levels) despite the presence of high, supraphysiological amounts in the circulation. There was also no relation between unbound DHT in the blood and the CSF, in which all DHT is unbound. These results differ from previous work on testosterone, the metabolic precursor of DHT. 5 alpha-Dihydrotestosterone propionate at the higher dose maintained suppressed levels of serum LH; LH in two out of four monkeys treated at the lower dose increased to levels observed in castrated, untreated rhesus monkeys. There was no predictable relationship between the amount of DHT in the CSF and levels of LH in the blood: by contrast, DHT in the blood was correlated with serum levels of LH. Levels of LH rose in monkeys in which total blood DHT fell below about 68 nmol/l and, even more obviously, if unbound DHT decreased to less than about 2 nmol/l. Differences between the distribution of testosterone and DHT between blood and CSF cannot be explained by serum binding, lipid solubility or clearance from the brain, and suggest that there may be some mechanism for excluding DHT from the CSF. Though DHT reaches the CSF from the blood in small amounts, levels there do not relate predictably to those in the vascular compartment. It seems unlikely, therefore, that levels of intracerebral DHT are controlled by changes in those of the blood.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.