1. Figure 1 Regulation of energy storage and energy release
Figure 1 | Regulation of energy storage and energy release. Three organ systems, each of which has a form of memory, are instrumental in energy regulation, particularly in storing and releasing energy from reserves. Energy reserves provide a 'memory' of food availability, food intake, general health status and times of previous energy shortage. a | Energy reserves are protected by the immune system and by the brain. Signals from energy storage tissues to the immune system and the brain via leptin indicate the amount of energy stored in the body's reserves. The brain and the immune system also signal to each other by mechanisms including IL-6, adrenaline and many others. b | In situations in which an individual encounters short-lived energy-demanding threats, such as predators, food shortages, extreme temperatures, infectious agents, wounding and haemorrhage, either the immune system or the brain can demand energy-rich fuels by stimulating insulin resistance, lipolysis and other energy-liberating pathways. Examples of mechanisms used by the brain or the immune system to induce insulin resistance include cortisol release92 by the hypothalamic–pituitary–adrenal (HPA) axis and also by immune cells, which can convert cortisone to cortisol locally, and vasopressin, which can stimulate lipolysis93. HPG axis, hypothalamic–pituitary–gonadal axis; RAA system, renin–angiotensin–aldosterone system.
Straub, R. H. (2017) The brain and immune system prompt energy shortage in chronic inflammation and ageing
Nat. Rev. Rheumatol. doi: /nrrheum