Chronic cold exposure has no effect on brown adipose tissue in newborn lambs born to well-fed ewes

1999 ◽  
Vol 11 (8) ◽  
pp. 415 ◽  
Author(s):  
J. J. Gate ◽  
L. Clarke ◽  
M. A. Lomax ◽  
M. E. Symonds

It has been previously shown in twin-bearing ewes fed only 60% of their metabolizable energy requirements for late pregnancy that chronic cold exposure induced by winter shearing of the ewes results in larger lambs with more brown adipose tissue. This effect appears to be primarily due to prevention of a decline in fetal body and tissue weights between 145 days’ gestation and 2 h after birth (i.e. 147 days’ gestation) in lambs born to underfed shorn ewes. The present study therefore examined the impact, in ewes that were well fed (i.e. received 100% of their metabolizable energy requirements) during the final month of gestation, of chronic cold exposure induced by winter shearing on lamb birthweight and perirenal adipose tissue composition as measured 2 h after birth. Perirenal adipose tissue was analysed for its thermogenic activity (i.e. GDP binding to mitochondria) and catecholamine content. These observations were combined with similar measurements made in near-term (i.e. 145 days’ gestation) fetuses sampled from well-fed unshorn ewes. There was no difference between lambs born to shorn or unshorn ewes with respect to birth-weight or perirenal adipose tissue weight and composition. Perirenal adipose tissue weight was higher in lambs born to unshorn ewes than in fetuses. The thermogenic activity of adipose tissue was 2-fold higher in lambs born to unshorn ewes compared with 145-day-old fetuses. Epinephrine was detectable only at very low levels in fetal perirenal adipose tissue, increasing 10-fold after birth, with no difference between lambs born to shorn or unshorn ewes. In newborn lambs, plasma growth hormone concentration was lower and insulin concentration higher in shorn compared with unshorn groups. In conclusion, chronic cold exposure induced by winter shearing had no effect on brown adipose tissue development in lambs born to well-fed ewes.

2016 ◽  
Vol 310 (10) ◽  
pp. R999-R1009 ◽  
Author(s):  
Takeshi Yoneshiro ◽  
Mami Matsushita ◽  
Satoshi Nakae ◽  
Toshimitsu Kameya ◽  
Hiroki Sugie ◽  
...  

Brown adipose tissue (BAT) contributes to whole body energy expenditure (EE), especially cold-induced thermogenesis (CIT), in humans. Although it is known that EE and CIT vary seasonally, their relationship with BAT has not been investigated. In the present study, we examined the impact of BAT on seasonal variations of EE/CIT and thermal responses to cold exposure in a randomized crossover design. Forty-five healthy male volunteers participated, and their BAT was assessed by positron emission tomography and computed tomography. CIT, the difference of EE at 27°C and after 2-h cold exposure at 19°C, significantly increased in winter compared with summer, being greater in subjects with metabolically active BAT (High BAT, 185.6 kcal/day vs. 18.3 kcal/day, P < 0.001) than those without (Low BAT, 90.6 kcal/day vs. −46.5 kcal/day, P < 0.05). Multivariate regression analysis revealed a significant interaction effect between season and BAT on CIT ( P < 0.001). The cold-induced drop of tympanic temperature (Tty) and skin temperature (Tskin) in the forehead region and in the supraclavicular region close to BAT deposits were smaller in the High BAT Group than in the Low BAT Group in winter but not in summer. In contrast, the drop of Tskin in the subclavicular and peripheral regions distant from BAT was similar in the two groups in both seasons. In conclusion, CIT increased from summer to winter in a BAT-dependent manner, paralleling cold-induced changes in Tty/Tskin, indicating a role of BAT in seasonal changes in the thermogenic and thermal responses to cold exposure in humans.


1982 ◽  
Vol 30 (1) ◽  
pp. 15 ◽  
Author(s):  
CR Tidemann

Information on seasonal changes in activity, body weight and brown adipose tissue weight was collected from a wild population of a small Australian vespertilionid, Eptesicus vulturnus. Both sexes, but especially females, became less active during the colder months of the year. Males maintained body weight and brown adipose tissue weight during winter, as do non-hibernating mammals. Females lost brown adipose tissue and body weight during winter, as do hibernators. The relationship between the sex differences in overwintering behaviour and the reproductive cycle is discussed.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sujoy Ghosh ◽  
Chul-Hong Park ◽  
Jisu Lee ◽  
Nathan Lee ◽  
Rui Zhang ◽  
...  

Abstract Background Brown adipose tissue (BAT) is specialized to dissipate energy in the form of heat. BAT-mediated heat production in rodents and humans is critical for effective temperature adaptation of newborns to the extrauterine environment immediately after birth. However, very little is known about whether and how fetal BAT development is modulated in-utero in response to changes in maternal thermal environment during pregnancy. Using BL6 mice, we evaluated the impact of different maternal environmental temperatures (28 °C and 18 °C) on the transcriptome of the placenta and fetal BAT to test if maternal cold exposure influences fetal BAT development via placental remodeling. Results Maternal weight gain during pregnancy, the average number of fetuses per pregnancy, and placental weight did not differ between the groups at 28 °C and 18 °C. However, the average fetal weight at E18.5 was 6% lower in the 18 °C-group compared to the 28 °C-group. In fetal BATs, cold exposure during pregnancy induced increased expression of genes involved in de novo lipogenesis and lipid metabolism while decreasing the expression of genes associated with muscle cell differentiation, thus suggesting that maternal cold exposure may promote fetal brown adipogenesis by suppressing the myogenic lineage in bidirectional progenitors. In placental tissues, maternal cold exposure was associated with upregulation of genes involved in complement activation and downregulation of genes related to muscle contraction and actin-myosin filament sliding. These changes may coordinate placental adaptation to maternal cold exposure, potentially by protecting against cold stress-induced inflammatory damage and modulating the vascular and extravascular contractile system in the placenta. Conclusions These findings provide evidence that environmental cold temperature sensed by the mother can modulate the transcriptome of placental and fetal BAT tissues. The ramifications of the observed gene expression changes warrant future investigation.


iScience ◽  
2021 ◽  
pp. 102434
Author(s):  
Winifred W. Yau ◽  
Kiraely Adam Wong ◽  
Jin Zhou ◽  
Nivetha Kanakaram Thimmukonda ◽  
Yajun Wu ◽  
...  

Metabolism ◽  
2021 ◽  
Vol 117 ◽  
pp. 154709 ◽  
Author(s):  
Tim Hollstein ◽  
Karyne Vinales ◽  
Kong Y. Chen ◽  
Aaron M. Cypess ◽  
Alessio Basolo ◽  
...  

2018 ◽  
Vol 120 (6) ◽  
pp. 9138-9146 ◽  
Author(s):  
Ziye Xu ◽  
Jiaqi Liu ◽  
Wenjing You ◽  
Yizhen Wang ◽  
Tizhong Shan

1995 ◽  
Vol 269 (1) ◽  
pp. R38-R47 ◽  
Author(s):  
J. M. Matz ◽  
M. J. Blake ◽  
H. M. Tatelman ◽  
K. P. Lavoi ◽  
N. J. Holbrook

The accumulation of heat shock proteins (HSPs) after the exposure of cells or organisms to elevated temperatures is well established. It is also known that a variety of other environmental and cellular metabolic stressors can induce HSP synthesis. However, few studies have investigated the effect of cold temperature on HSP expression. Here we report that exposure of Institute of Cancer Research (ICR) mice to cold ambient temperatures results in a tissue-selective induction of HSPs in brown adipose tissue (BAT) coincident with the induction of mitochondrial uncoupling protein synthesis. Cold-induced HSP expression is associated with enhanced binding of heat shock transcription factors to DNA, similar to that which occurs after exposure of cells or tissues to heat and other metabolic stresses. Adrenergic receptor antagonists were found to block cold-induced HSP70 expression in BAT, whereas adrenergic agonists induced BAT HSP expression in the absence of cold exposure. These findings suggest that norepinephrine, released in response to cold exposure, induces HSP expression in BAT. Norepinephrine appears to initiate transcription of HSP genes after binding to BAT adrenergic receptors through, as yet, undetermined signal transduction pathways. Thermogenesis results from an increase in activity and synthesis of several metabolic enzymes in BAT of animals exposed to cold challenge. The concomitant increase in HSPs may function to facilitate the translocation and activity of the enzymes involved in this process.


Sign in / Sign up

Export Citation Format

Share Document