EFFECT OF BIRTH AND AMBIENT TEMPERATURE ON ABUNDANCE OF LONG AND SHORT FORMS OF THE PROLACTIN RECEPTOR (PRLR) IN OVINE BROWN ADIPOSE TISSUE

1999 ◽  
Vol 27 (1) ◽  
pp. A49-A49
Author(s):  
J. Bispham ◽  
L. Heasman ◽  
L. Clarke ◽  
P. Ingleton ◽  
T. Stephenson ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Prolactin Receptor ◽  
Short Forms ◽  
Brown Adipose

Rat Fetal Brown Adipose Tissue in vitro: Effects of Hormones and Ambient Temperature

Neonatology ◽  
1976 ◽  
Vol 30 (1-4) ◽  
pp. 40-48 ◽  
Author(s):  
J. Frohlich ◽  
P. Hahn ◽  
L. Kirby ◽  
W. Webber
Keyword(s):  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Brown Adipose

Cold-defense function of brown adipose tissue during sleep

1993 ◽  
Vol 265 (5) ◽  
pp. R1060-R1064 ◽  
Author(s):  
M. Calasso ◽  
E. Zantedeschi ◽  
P. L. Parmeggiani
Keyword(s):  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Nasal Mucosa ◽  
Interscapular Brown Adipose Tissue ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Before And After ◽  
Defense Function

Rats with chronically implanted electroencephalograph scalp electrodes and thermistors were exposed to 24 and 4 degrees C ambient temperatures during the light hours before and after acclimation to 4 degrees C ambient temperature for 9 days. During synchronized sleep, deep interscapular temperature was higher at 4 degrees C than at 24 degrees C both before and after acclimation to cold. After ablation of brown adipose tissue, deep interscapular temperature was lower at 4 degrees C than at 24 degrees C during synchronized sleep. In the presence of brown adipose tissue, deep interscapular temperature decreased sharply during desynchronized sleep at 4 degrees C both before and after acclimation to cold. This decrease was subsequent to and correlated with an increase in the temperature of the nasal mucosa. The decrease in deep interscapular temperature during desynchronized sleep at 4 degrees C ambient temperature was markedly reduced by ablation of the interscapular brown adipose tissue.

Cortisol has no effect on prolactin receptor (PRLR) abundance in brown adipose tissue (BAT) in late gestation fetal sheep

2001 ◽  
Vol 29 (1) ◽  
pp. A39-A39
Author(s):  
S. Pearce ◽  
H. Budge ◽  
A. Forhead ◽  
A. Fowden ◽  
P. Ingleton ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Prolactin Receptor ◽  
Late Gestation ◽  
Fetal Sheep ◽  
Brown Adipose

Fetal and neonatal adipose maturation: a primary site of cytokine and cytokine-receptor action

2001 ◽  
Vol 29 (2) ◽  
pp. 80-85 ◽  
Author(s):  
T. Stephenson ◽  
H. Budge ◽  
A. Mostyn ◽  
S. Pearce ◽  
R. Webb ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Maternal Nutrition ◽  
Short Form ◽  
Uncoupling Protein ◽  
Prolactin Receptor ◽  
Late Gestation ◽  
Metabolic Adaptation ◽  
Postnatal Life ◽  
Brown Adipose

During late gestation, the maturation of fetal adipose tissue is geared towards the synthesis of high levels of uncoupling protein 1 (UCP1), which is unique to brown adipose tissue. At birth, rapid activation of UCP1 ensures a large increase in heat production. These adaptations are nutritionally sensitive, and may be mediated in part by rapid changes in prolactin and leptin secretion after birth. Restriction of maternal nutrition reduces adipose tissue deposition, with no effect on UCP1. Increased maternal food intake results in increases in levels of UCP1 and the short form of the prolactin receptor, but in a decrease in adipose tissue content per kg of fetus. The ontogeny of the long and short forms of the prolactin receptor follows that of UCP1, to peak at birth. Then, during postnatal life, UCP1 disappears in parallel with the loss of prolactin receptors. Treatment of neonatal lambs with prolactin increases body temperature and the thermogenic potential of brown adipose tissue. In contrast, acute leptin treatment results in maintenance of colonic temperature, but chronic leptin treatment accelerates UCP1 loss. Increasing our understanding of the interaction between prolactin and leptin during perinatal development may enable the establishment of strategies aimed at maximizing adipose tissue development in order to promote metabolic adaptation to the extra-uterine environment.

scholarly journals Relationship between the Daily Rhythm of Distal Skin Temperature and Brown Adipose Tissue 18F-FDG Uptake in Young Sedentary Adults

2019 ◽  
Vol 34 (5) ◽  
pp. 533-550 ◽  
Author(s):  
Francisco M. Acosta ◽  
Borja Martinez-Tellez ◽  
Denis P. Blondin ◽  
François Haman ◽  
Patrick C. N. Rensen ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Skin Temperature ◽  
Daily Rhythm ◽  
Relative Amplitude ◽  
Fdg Uptake ◽  
Brown Adipose ◽  
The Mean ◽  
Intraday Variability

The present study examines whether the daily rhythm of distal skin temperature (DST) is associated with brown adipose tissue (BAT) metabolism as determined by 18F-fluorodeoxyglucose (18F-FDG) uptake in young adults. Using a wireless thermometer (iButton) worn on the nondominant wrist, DST was measured in 77 subjects (26% male; age 22 ± 2 years; body mass index 25.2 ± 4.8 kg/m2) for 7 consecutive days. The temperatures to which they were habitually exposed over the day were also recorded. The interday stability of DST was calculated from the collected data, along with the intraday variability and relative amplitude; the mean temperature of the 5 and 10 consecutive hours with the maximum and minimum DST values, respectively; and when these hours occurred. Following exposure to cold, BAT volume and mean and peak standardized 18F-FDG uptake (SUVmean and SUVpeak) were determined for each subject via static 18F-FDG positron emission tomography/computed tomography scanning. Relative amplitude and the time at which the 10 consecutive hours of minimum DST values occurred were positively associated with BAT volume, SUVmean, and SUVpeak ( p ≤ 0.02), whereas the mean DST of that period was inversely associated with the latter BAT variables ( p ≤ 0.01). The interday stability and intraday variability of the DST were also associated (directly and inversely, respectively) with BAT SUVpeak ( p ≤ 0.02 for both). All of these associations disappeared, however, when the analyses were adjusted for the ambient temperature to which the subjects were habitually exposed. Thus, the relationship between the daily rhythm of DST and BAT activity estimated by 18F-FDG uptake is masked by environmental and likely behavioral factors. Of note is that those participants exposed to the lowest ambient temperature showed 3 to 5 times more BAT volume and activity compared with subjects who were exposed to a warmer ambient temperature.

scholarly journals Influence of maternal dexamethasone administration on thermoregulation in lambs delivered by caesarean section

1998 ◽  
Vol 156 (2) ◽  
pp. 307-314 ◽  
Author(s):  
I Clarke ◽  
L Heasman ◽  
ME Symonds
Keyword(s):  
Adipose Tissue ◽  
Caesarean Section ◽  
Thyroid Hormones ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Premature Delivery ◽  
Dexamethasone Treatment ◽  
Brown Adipose ◽  
Colonic Temperature

We have previously shown that lambs delivered by caesarean section 1 week prematurely become hypothermic due to reduced brown adipose tissue function in conjunction with low plasma concentrations of cortisol and thyroid hormones. The present study therefore aimed to determine whether maternal dexamethasone (a synthetic corticosteroid) administration could improve thermoregulation in premature lambs to the extent that they become similar to term lambs. Lambs were either delivered by caesarean section into a warm (30 degrees C; WD) or cool (15 degrees C; CD) ambient temperature at 140 days of gestation, 2 days after maternal dexamethasone treatment, or at 146 days for controls. During the first 30 min of life the decline in colonic temperature was greater in dexamethasone treated lambs compared with controls delivered into the same ambient temperature. All lambs then restored colonic temperature although this adaptation took longest in dexamethasone treated lambs CD but these subsequently attained highest plateau colonic temperatures. Oxygen consumption, breathing frequency and plasma free fatty acid concentrations were highest in dexamethasone treated lambs CD. There were no differences in plasma thyroid hormones between groups, but cortisol concentrations were lower in dexamethasone treated lambs irrespective of delivery temperature. Analysis of brown adipose tissue samples at 6 h of life demonstrated that dexamethasone treated lambs WD had more uncoupling protein and, in both dexamethasone treated and control lambs, uncoupling protein content was higher in lambs CD compared with those WD. An effect of ambient temperature on thermogenic activity was only observed in the dexamethasone treated group. It is concluded that maternal dexamethasone treatment can significantly improve thermoregulation after birth following premature delivery by caesarean section. As a consequence, dexamethasone treated lambs delivered 1 week prematurely do not remain hypothermic and have higher or similar colonic temperatures compared with untreated lambs born 1-2 days before term.

Brown Adipose Tissue and Its Uncoupling Protein in Chronically Hypoxic Rats

1997 ◽  
Vol 93 (4) ◽  
pp. 349-354 ◽  
Author(s):  
Jacopo P. Mortola ◽  
Lina Naso
Keyword(s):  
Adipose Tissue ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Body Mass ◽  
Uncoupling Protein ◽  
Total Proteins ◽  
Tissue Mass ◽  
Brown Adipose ◽  
Adipose Tissue Mass ◽  
Old Rats

1. Hypoxia is known to decrease thermogenesis. We set out to determine whether this is accompanied by alterations in the brown adipose tissue, which is a major source of non-shivering thermogenesis. 2. Measurements were performed on 25- and 64-day-old rats, after 4 days of hypoxia (10% inspired O2), and on ∼3.5-month-old rats in hypobaric hypoxia since birth, at an ambient temperature of 25°C. 3. All hypoxic rats had higher haematocrit and lower body mass than corresponding controls. 4. In the 25-day-old rats, hypoxia had minimal and non significant effects on brown adipose tissue mass, proteins and DNA concentration. The content of the mitochondrial uncoupling protein thermogenin, evaluated by immunoblot after electrophoretic separation, relative to the cytoskeleton actin (UCP/Act), was not significantly altered. 5. In 25-day-old rats exposed for 4 days to cold (ambient temperature = 7–9°C), brown adipose tissue was hyperplastic, with increased UCP/Act; hypoxia did not appreciably alter the response to cold. 6. In the 2-month-old rats, after 4 days of hypoxia UCP/Act was reduced to about 40% of control. 7. In the 3.5-month-old rats maintained in hypoxia since birth, brown adipose tissue mass was reduced in proportion to body mass, with little effect on total proteins and DNA; UCP/Act was decreased to about 50% of control. 8. We conclude that chronic hypoxia had a minimal effect on brown adipose tissue total proteins and DNA content. However, the uncoupling protein content can be greatly reduced, depending upon age and duration of hypoxia.

Influence of maternal bodyweight on adaptation after birth in near-term lambs delivered by Caesarean section

1998 ◽  
Vol 10 (4) ◽  
pp. 333 ◽  
Author(s):  
Michael E. Symonds ◽  
Lynne Clarke
Keyword(s):  
Adipose Tissue ◽  
Respiratory Failure ◽  
Caesarean Section ◽  
Ambient Temperature ◽  
Brown Adipose Tissue ◽  
Umbilical Vein ◽  
Brown Adipose ◽  
Caesarean Section Delivery ◽  
Near Term ◽  
Colonic Temperature

The present study investigated the influence of maternal bodyweight on adaptation after birth in near-term lambs delivered by caesarean section. One twin lamb from a heavy (>60 kg) or light ewe (<55 kg) was randomly taken and immediately placed into a warm (30˚C) ambient temperature and its twin then delivered into a cool (15˚C) ambient temperature. Continuous recordings of colonic temperature were then made followed by measurements of thermoregulation and brown adipose tissue function up to 6 h of life. Following caesarean section delivery colonic temperature rapidly declined over the first 30 min of life, a response that was greater in lambs at 15˚C. Irrespective of ambient temperature all lambs born to heavy ewes commenced shivering within 15 min of birth and were able to restore body temperature. These adap-tations were only observed in warm-delivered lambs born to light ewes, as cool-delivered lambs failed to shiver, became hypothermic and 4 out of 6 lambs exhibited respiratory failure. Umbilical vein plasma thyroid hormone concentrations were lower in lambs born to light compared with heavy ewes. Plasma T3 concentrations remained lower in warm-delivered lambs born to light ewes until 2 h after birth when heat production and colonic temperature were not significantly different from warm delivered lambs born to heavy ewes. Lambs born to light ewes possessed less brown adipose tissue than those born to heavy ewes. In conclusion, maternal bodyweight has a critical influence on survival following caesarean section birth that is dependent on the ambient temperature into which a lamb is delivered.

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