Thermoregulation energy balance regulatory peptides recent developments

Abstract

Energy balance of the body is determined mainly by the function of various hypothalamic and brainstem nuclei, according to a complex interaction between the regulation of body temperature (actual metabolic rate vs. heat loss) and regulation of body weight (metabolic rate vs. food intake). The direct effect of central anabolic neuropeptides (neuropeptide Y, orexins, melanin concentrating hormone, etc.) is to enhance food intake and suppress metabolic rate with a tendency to cause hypothermia, while central catabolic neuropeptides (melanocortins, corticotropin releasing factor, cocaine-amphetamine regulated peptide, etc.) suppress food intake and enhance energy expenditure with a tendency to induce hyperthermia. Many other neuropeptides are neither clearly anabolic, nor clearly catabolic, but still influence these complex hypothalamic/brainstem functions. Some peripheral peptides (e.g. leptin, insulin, ghrelin) acting at either peripheral or cerebral sites also contribute to the regulation of energy balance. The prevailing thermoregulatory status, the substances or neural signals representing actual feeding vs. established nutritional states, and the aging process may modify the expression and/or activity of peripheral and central peptides and peptide receptors.

Central alpha-MSH, energy balance, thermal balance, and antipyresis

“…bombesin or neurotensin suppresses food intake (FI) but also suppresses metabolic rate and induces hypothermia (Tsushima et al, 2003;Tsushima and Mori, 2005;Popp et al, 2007;Gordon et al, 2003;Ohinata et al, 2004). The present study aimed to investigate whether or not hypothalamic alpha-MSH can be regarded as a catabolic peptide in every sense (Szé kely et al, 2010;Szé kely and Szelé nyi, 2005), i.e. : whether or not its anorexic effects are completed by corresponding coordinated hypermetabolic and consequent thermal changes.…”

Age-related alterations in the central thermoregulatory responsiveness to alpha-MSH

“…The central melanocortin system plays a crucial role in the regulation of energy balance (Cone, 1999;Robinson et al, 2000;Schwartz et al, 2000;Szekely et al, 2010). Its central catabolic actions appear to be coordinated, as both the anorexigenic (food intake reducing) and the hypermetabolic effects result in weight loss (Székely and Szelényi, 2005).…”

Distribution of orexin-A immunoreactive neurons and their terminal networks in the brain of the rock hyrax, Procavia capensis

“…In addition to this the hyraxes are diurnally active and their sleep has been described as being polycyclic (Snyder, 1974). Moreover, they are poor thermoregulators (McNairn and Fairall, 1984;Brown and Downs, 2006) and orexins are clearly involved in thermoregulation and energy balance (Szekely et al, 2010;Teske et al, 2010).…”