Effects of maternal undernutrition during late pregnancy on the regulatory factors involved in growth and development in ovine fetal perirenal brown adipose tissue

We have recently shown that ovine fetal brown adipose tissue (BAT) contains two distinct iodothyronine 5'-monodeiodinase (5'MDI) activities, one with a high Km (type I) and another with a low Km (type II). Both activities increased to maximum levels near term (150 days gestation). BAT plays a major role in neonatal temperature regulation in lambs, and available evidence suggests that BAT 5'MDI activity is closely linked to thermogenic capacity. To better characterize the changes in 5'MDI after birth, we studied both type I and type II 5'MDI in lamb BAT from the time of birth to 30 days of postnatal age. Type I 5'MDI activity [pmol 3,5,3'-triiodothyronine (T3).mg protein-1.h-1] showed no significant changes during the first 11 days after birth [newborn (NB), 95 +/- 16; 1 day, 83 +/- 20; 3-4 days, 80 +/- 11; 10-11 days, 92 +/- 28]. Activity decreased significantly at 30 days (24 +/- 8.9, P less than 0.05). On the other hand, the type II 5'MDI activity (fmol I- released.mg protein-1.h-1) increased significantly (P less than 0.01) during the first 4 days, (NB, 348 +/- 23; 1 day, 679 +/- 37; 3-4 days, 785 +/- 199), decreased toward NB values (401 +/- 87) at 10-11 days of age, and fell to 66 +/- 31 at 30 days (P less than 0.05 vs. NB). Kinetic analysis of BAT type II thyroxine 5'MDI revealed a rise in maximum velocity from NB to 1 and 3-4 days of age without a change in the enzymatic activity Km.(ABSTRACT TRUNCATED AT 250 WORDS)

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Iodothyronine 5′-deiodinase activity and thyroid hormone content in brown adipose tissue during the breeding cycle of the rat

Biochemical Journal ◽

10.1042/bj2550457 ◽

1988 ◽

Vol 255 (2) ◽

pp. 457-461 ◽

Cited By ~ 3

Author(s):

O Viñas ◽

M Giralt ◽

M J Obregón ◽

R Iglesias ◽

F Villarroya ◽

...

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Late Pregnancy ◽

Brown Fat ◽

Breeding Cycle ◽

Activity Levels ◽

Pregnant Rats ◽

Deiodinase Activity ◽

Brown Adipose ◽

Pregnancy And Lactation

Brown adipose tissue iodothyronine 5′-deiodinase activity is significantly lower in 17-day pregnant rats compared with virgin controls and remains low during late pregnancy and lactation. It fully recovers with abrupt weaning, but only partially with spontaneous weaning. Even though this profile of changes is remarkably in step with the known pattern of modifications in brown fat thermogenesis during the breeding cycle, the lowered iodothyronine 5′-deiodinase activity appearing between days 15 and 17 of pregnancy occurs earlier than the reduction in brown adipose tissue thermogenesis. Brown fat 3,3′,5-tri-iodothyronine content is also reduced in late pregnant, early and mid-lactating rats, most probably as a consequence of the lowered 5′-deiodination of thyroxine in situ. Acute insulin treatment increases brown fat iodothyronine 5′-deiodinase activity in virgin animals as well as in late-pregnant and lactating rats, despite the lowered basal enzyme activity levels in the latter groups. Thus an impaired response to insulin in brown fat does not appear to be a factor leading to the lowered iodothyronine 5′-deiodinase activity during late pregnancy and lactation.

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Mitochondrial biogenesis in brown adipose tissue is associated with differential expression of transcription regulatory factors

Cellular and Molecular Life Sciences ◽

10.1007/pl00012516 ◽

2002 ◽

Vol 59 (11) ◽

pp. 1934-1944 ◽

Cited By ~ 18

Author(s):

J. A. Villena ◽

M. C. Carmona ◽

M. Rodriguez de la Concepción ◽

M. Rossmeisl ◽

O. Viñas ◽

...

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Differential Expression ◽

Mitochondrial Biogenesis ◽

Regulatory Factors ◽

Brown Adipose

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Brown adipose tissue growth and development: significance and nutritional regulation

Frontiers in Bioscience ◽

10.2741/3807 ◽

2011 ◽

Vol 16 (1) ◽

pp. 1589 ◽

Cited By ~ 31

Author(s):

Michael Carey Satterfield

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Growth And Development ◽

Tissue Growth ◽

Nutritional Regulation ◽

Brown Adipose

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Effect of Maternal Undernutrition during Late Pregnancy on Growth and Development of Ovine Fetal Visceral Organs

Asian-Australasian Journal of Animal Sciences ◽

10.5713/ajas.2009.90131 ◽

2009 ◽

Vol 22 (12) ◽

pp. 1633-1639 ◽

Cited By ~ 6

Author(s):

F. Gao ◽

Y. C. Liu ◽

X. Z. Hou

Keyword(s):

Growth And Development ◽

Late Pregnancy ◽

Maternal Undernutrition ◽

Visceral Organs ◽

Ovine Fetal

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Functional characterization of human brown adipose tissue metabolism

Biochemical Journal ◽

10.1042/bcj20190464 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1261-1286 ◽

Cited By ~ 3

Author(s):

Marie Anne Richard ◽

Hannah Pallubinsky ◽

Denis P. Blondin

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Functional Characterization ◽

Human Infants ◽

Positron Emission ◽

Brown Adipose ◽

Treatment Of Obesity ◽

And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

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