Endocrine Abstracts

Two major timing systems control all living organisms. The first is the “circadian” clock, which drives a vast array of internal physiological systems. This includes timing of hormone secretion, and interaction with intra-cellular signalling pathways. The second system is the less understood photoperiodic clock, in which virtually all life forms adapt to the passage of the seasons. Here, processes as diverse as reproduction, sexual behaviour, parental care, metabolis...

Biological clocks drive the physiology and behaviour of all organisms, from bacteria to humans. Much attention has focused on the circadian 24 h clock, and rapid progress made in defining key molecular components that regulate our rhythmic physiology. The circadian clock also drives a linked timing system that controls annual cycles of hormone secretion and metabolism, this is most evident in wild species, such as hibernating mammals. Annual cycles are also key feature of dome...

The circadian clock is a key regulator of immune responses. Both circulating and resident immune cells possess intrinsic timers, which act to impart time-of-day variation in their function. It is now becoming evident that the circadian clock is also critically involved in regulating the function of endogenous anti-inflammatory glucocorticoid hormones. Consequently, we see variation in an animal’s inflammatory responses dependent on the time the stimulus was delivered. Thi...

One in five people in the UK is affected by lung disease, along with millions more worldwide. Glucocorticoids represent the most utilized anti-inflammatory therapy for the treatment of pulmonary inflammation, however a subset of patients exist which do not respond to therapeutically relevant doses.The non-ciliated bronchial epithelial (Clara) cells have been identified as key mediators of the pulmonary inflammatory response. The glucocorticoid receptor (...

Adiponectin, an exclusive adipose-derived hormone, circulates at high concentration, and exerts metabolic effects. Adiponectin levels in the circulation correlate negatively with BMI, and low adiponectin concentrations are associated with the low grade inflammation and metabolic dysfunction that accompanies obesity. Adiponectin has been reported to have potent anti-inflammatory activities, and to exert these effects by regulating macrophage function. The mechanism of adiponect...

An extraordinary array of behavioural and physiological systems is regulated by endogenous circadian timekeepers within mammals. This circadian machinery is comprised of intricate autoregulatory transcription feedback loops, which interact to generate a time delay of approximately 24 hours in the cyclical transcription of components. In addition to the master clock in the suprachiasmatic nucleus it is clear that peripheral tissues also express clock components. The central clo...

Reproductive timing strongly influences the fitness of the individual. While most vertebrates rely on photoperiodic changes to induce seasonal reproduction, the arctic ground squirrel (AGS) naturally undergoes reproductive maturation in a photoperiod-independent manner. In addition, males spontaneously activate their reproductive axis during hibernation, but the timing of reproduction is sensitive to external cues. We are using electron microscopy to examine, define, and measu...