Searchable abstracts of presentations at key conferences in endocrinology

ea0011oc12 | Steroids and reproductive endocrinology | ECE2006

Expression profiling of genes in the testis of rhesus macaques during development and aging

Urbanski HF , Garyfallou VT , Lemos DR , Downs JL , Brown DI

Men show an age-associated decline in 24-hour circulating testosterone levels, but the reason for this decline is unclear. To shed light on the possible cause we first established that male rhesus monkeys undergo a similar decline in testosterone with age. Testosterone from young adult (∼10 years) and old (∼26 years) unanaesthetized males was measured by RIA from blood samples collected remotely through a vascular catheter, every 30 minutes for 24 hours. In both yo...

ea0011p678 | Reproduction | ECE2006

Changes in GnRH gene expression in the medial basal hypothalamus of rhesus macaques across the menstrual cycle

Urbanski HF , Noriega N , Garyfallou VT , Downs JL , Kohama SG

Rhesus macaques, like humans, express two molecular forms of gonadotropin-releasing hormone (GnRH-I and GnRH-II). Although the role of GnRH-I in the control of the reproductive axis is well-established, the physiological role of GnRH-II is less clear. Both forms of GnRH are highly expressed in the monkey hypothalamus and both forms are highly effective at stimulating LH and FSH release in vivo. However, estradiol appears to affect GnRH-I and GnRH-II gene expression diff...

ea0012oc1 | Young Endocrinologist prize session | SFE2006

The effects of age and calorie restriction on 24-hour plasma melatonin and activity rhythms in the rhesus macaque (Macaca mulatta)

Downs JL , Aghazadeh-Sanai N , Mattison JA , Ingram DK , Kohama SG , Urbanski HF

A characteristic of aging in humans, as well as in nonhuman primates, is the disruption and attenuation of many biological rhythms. A desynchronization or dampening of cyclical neuroendocrine patterns, such as the circulating melatonin rhythm, may help to explain age-related disturbances in sleep and daytime alertness. Although the cause of age-associated disruptions of biological rhythms is largely unknown, it may be partially due to cumulative neuronal damage of relevant bra...