Sex differences in thermoregulation in mammals: Implications for energy homeostasis

Abstract

Thermal homeostasis is a fundamental process in mammals, which allows the maintenance of a constant internal body temperature to ensure an efficient function of cells despite changes in ambient temperature. Increasing evidence has revealed the great impact of thermoregulation on energy homeostasis. Homeothermy requires a fine regulation of food intake, heat production, conservation and dissipation and energy expenditure. A great interest on this field of research has re-emerged following the discovery of thermogenic brown adipose tissue and browning of white fat in adult humans, with a potential clinical relevance on obesity and metabolic comorbidities. However, most of our knowledge comes from male animal models or men, which introduces unwanted biases on the findings. In this review, we discuss how differences in sex-dependent characteristics (anthropometry, body composition, hormonal regulation, and other sexual factors) influence numerous aspects of thermal regulation, which impact on energy homeostasis. Individuals of both sexes should be used in the experimental paradigms, considering the ovarian cycles and sexual hormonal regulation as influential factors in these studies. Only by collecting data in both sexes on molecular, functional, and clinical aspects, we will be able to establish in a rigorous way the real impact of thermoregulation on energy homeostasis, opening new avenues in the understanding and treatment of obesity and metabolic associated diseases.

Knockdown of Esr1 from DRD1-Rich Brain Regions Affects Adipose Tissue Metabolism: Potential Crosstalk between Nucleus Accumbens and Adipose Tissue

“…There was also a significant sex-by-genotype interaction such that, among males only, WAT leptin mRNA levels were higher among KD mice compared to WT males. We and others have shown females to be more sensitive to WAT browning [ 21 , 22 ], a finding supported herein. Indeed, there were sex differences in WAT UCP1 staining, gene expression, and protein expression.…”

“…BAT thermogenesis, driven by UCP1, contributes to resting energy expenditure. Given the known sex differences in BAT [ 22 ] and WAT browning [ 21 , 26 ] and accumulating evidence that central E2 signaling affects BAT activation [ 27 ], it is not entirely surprising that BAT appeared to be affected by the Esr1 mutation in the present study. It is well established that E2 signaling is permissive for WAT browning, which may be mediated centrally [ 28 ], although the mechanisms are not clear.…”

Thermotherapy has Sexually Dimorphic Responses in APP/PS1 Mice

“…Despite Tc modulation by estradiol and progesterone [31], the absence of a response is not solely attributed to sex hormones, as thermotherapy increased Tc in female C57BL/6 mice. In mice, thermoregulatory sex differences have not been fully elucidated, but females prefer warmer environments than males regardless of gonadal factors [31] despite having higher Tc [32]. This suggests the differential responses we observed in the present study were not driven by sex hormones, but rather Aβ 42 accumulation and aggregation.…”

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

“…Sex, pregnancy and lactation are factors that change thermoregulation in other mammalian species that gives birth to altricial young, such as for example humans and mice (Kaciuba‐Uscilko and Grucza, 2001 ; Jackson et al., 2014 ). Body heat and body temperature are indeed highly dependent on sexual hormones in mammals (Fernández‐Peña et al., 2023 ). Progesterone causes changes in the hypothalamus that determine shifts in the body temperature towards higher temperatures.…”