Behaviorally subordinate female marmosets undergo social suppression of ovulation and hypoestrogenism, as well as chronic reductions in circulating basal cortisol concentrations. Because estrogen elevates hypothalamic-pituitary-adrenal axis activity and circulating glucocorticoid levels in other species, we tested the hypothesis that socially induced hypoestrogenism contributes to cortisol redu...

Clinical studies have indicated that circulating bile acid (BA) concentrations increase following bariatric surgery, especially following malabsorptive procedures such as Roux-en-Y gastric bypasses (RYGB). Moreover, total circulating BA concentrations in patients following RYGB are positively correlated with serum glucagon-like peptide-1 concentrations and inversely correlated with postprandial...

Cross-sectional studies have suggested an association between the main female hormone, 17b-estradiol (E2), and the risk of type 2 diabetes (T2D) in postmenopausal women (1,2). Even prospective studies have found that among postmenopausal women not using hormone therapy, higher circulating levels of total and free E2 were strongly and prospectively associated with increased longterm risk of T2D,...

BACKGROUND Circulating concentrations of sex hormone-binding globulin (SHBG) have been associated with cardiovascular diseases, type 2 diabetes, metabolic syndrome, and hormone-dependent cancers; however, correlates of SHBG concentrations are not well understood. METHODS We comprehensively investigated correlates of SHBG concentrations among 13 547 women who participated in the Women's Health...

BACKGROUND Short-term trials indicate that intensive physical activity may influence endogenous sex hormone concentrations. However, the relationship between usual daily physical activity and endogenous hormones in postmenopausal women in the general population is still uncertain. OBJECTIVE AND METHODS To determine the relationship between usual physical activity and endogenous sex hormones i...

Polychlorinated biphenyls (PCBs) are well known to reduce the concentrations of thyroid hormones in the circulation of experimental animals (Bastomsky et al., 1976; Brouwer et al., 1998). Moreover, circulating levels of PCBs have been reported to co-vary with various measures of thyroid status in humans (Koopman-Esseboom et al., 1997; Osius et al., 1999). These observations form the basis for t...

BACKGROUND Hepcidin-25 reduces iron absorption by binding to the intestinal iron transporter ferroportin and causing its degradation. Currently, little is known about the basal regulation of circulating hepcidin-25. In addition, although erythropoietin administration has been reported to decrease the circulating hepcidin concentration, information is limited regarding how other stimulators of e...

The gut-derived hormone, peptide YY (PYY) reduces food intake and enhances satiety in both humans and animals. Obese individuals also have a deficiency in circulating peptide YY, although whether this is a cause or a consequence of obesity is unclear. Our aims were to determine whether peptide YY (PYY) over-expression may have therapeutic effects for the treatment of obesity by altering energy ...

Rat liver, as well as other species, contains numerous sex-dependent isoforms of cytochrome P450 (P450) that are regulated by the sexually dimorphic profiles of circulating growth hormone. During puberty, young adulthood, and senescence, changes in the hormonal profiles appear to be responsible for alterations in age-associated expression levels of selective P450 isoforms. In contrast, little i...

Fecal hormone analysis is a useful tool for frequent, non-invasive sampling of free-living animals. Estrogens fluctuate throughout life among reproductive states in female animals, and intensive repetitive sampling can permit accurate assessment of female reproductive condition. This type of repetitive sampling is difficult in large carnivores, including the spotted hyena (Crocuta crocuta). Pat...