Activation of Kappa Opioid Receptor Regulates the Hypothermic Response to Calorie Restriction and Limits Body Weight Loss.

ABSTRACT: Mammals maintain a nearly constant core body temperature (T_b) by balancing heat production and heat dissipation. This comes at a high metabolic cost that is sustainable if adequate calorie intake is maintained. When nutrients are scarce or experimentally reduced such as during calorie restriction (CR), endotherms can reduce energy expenditure by lowering T_b [1-6]. This adaptive response conserves energy, limiting the loss of body weight due to low calorie intake [7-10]. Here we show that this response is regulated by the kappa opioid receptor (KOR). CR is associated with increased hypothalamic levels of the endogenous opioid Leu-enkephalin, which is derived from the KOR agonist precursor dynorphin [11]. Pharmacological inhibition of KOR, but not of the delta or the mu

SUBMITTER: Cintron-Colon R 

PROVIDER: S-EPMC6917995 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature