Brown and White Fats: Development in the Hamster

Smalley, Robert L.; Smalley, Katherine N.

doi:10.1126/science.157.3795.1449

Cited by 20 publications

(11 citation statements)

References 8 publications

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“…Not until the 16th day after birth have the majority of cells ob tained the typical multilocular appearance of brown fat cells (19,26,28). Our results show that the increase in BAT mass starts at this age.…”

Section: Discussionsupporting

confidence: 60%

Brown Fat Thermoregulation in Developing Hamsters (<i>Mesocricetus auratus</i>): a GDP-Binding Study

Sundin

Herron

Cannon³

1981

Neonatology

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The thermogenic capacity of brown fat from neonatal and developing hamsters was investigated. The method used was to measure the capacity of brown fat mitochondria to bind externally added guanosine diphosphate (GDP). This gives an estimate of the number of proton-conducting channels and hence the capacity of heat production in the mitochondria. At an age of 12 days post-partum the GDP-binding capacity is low: 0.14 nmol GDP/mg mitochondrial protein. Thereafter the capacity shows a steady increase up to 0.54 nmol/mg at 20 days. The peak is followed by a slow decrease down to the level of the adult hamster: 0.32 nmol/mg. This pattern of brown fat development is strikingly similar to reports on the development of oxygen consumption measured on whole animals or on the ability to maintain a constant body temperature when the ambient temperature is lowered. The calorigenic response to injected noradrenaline also follows this pattern. It is therefore justified to suggest that brown fat is a major effector of regulative metabolic heat production in the developing hamster.

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Section: Discussionsupporting

confidence: 60%

Brown Fat Thermoregulation in Developing Hamsters (<i>Mesocricetus auratus</i>): a GDP-Binding Study

Sundin

Herron

Cannon³

1981

Neonatology

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“…catecholamine release [22]. The brown adipose tissue of the interscapular and subscapular areas was dissected free of muscle and white fat and placed in Krebs Ringer phosphate buffer (containing 1/2 normal Ca++ concentration throughout) with 4 bovine serum albumin.…”

Section: Isolation Of Brown Fat Cellsmentioning

confidence: 99%

Oxidative Metabolism in Cells Isolated from Brown Adipose Tissue

Prusiner

Cannon

Lindberg

1968

European Journal of Biochemistry

118

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1.Brown fat cells exhibit a classical mitochondria1 electron transport system. 2. The respiration of brown fat cells can be stimulated by nor-epinephrine and this hormonally mediated respiration can be mimicked by oleate.3. Both nor-epinephrine and oleate-stimulated respiration can be blocked by rotenone, antimycin, azide and malonate, and the antimycin block can be by-passed by tetramethyl-p-phen y lenediamine .4. a-Glycerol phosphate and succinate were found to stimulate respiration. 5. The potent a-glycerol phosphate oxidase cannot quantitatively contribute to the respiration evoked during catecholamine induced thermogenesis.It is well-known that catecholamines are able to affect a number of systems in the whole animal, such as glycogenolysis by activating the phosphorylase, glycolysis by activating phosphofructokinase and lipolysis by activating the triglyceride lipase. I n recent years the action of catecholamines on brown adipose tissue has received much attention [I -31. Numerous studies carried out in vivo have shown that the sympathetic nervous system, which releases catecholamines on stimulation, controls thermogenesis in brown fat upon cold exposure and probably on arousal from hibernation [3 -81. Several investigators have demonstrated the rich sympathetic innervation of brown fat where the catecholamine content of the tissue was observed to be 0.5-1.0 pg/gram of tissue, a figure equalled only by the heart [9--121. It is known that the thermogenic effect is linked with increased fatty acid mobilisation and oxidation [I3 to i5]. The work presented here has been carried out in order to investigate whether the catecholamine affects all the above systems or rather whether the activity is restricted to one or more of the functions mentioned.The experiments of Heim and Hull The events leading to this large stimulation of 0, utilization and the nature of the oxidative mechanism will be discussed here. METHODS AND MATERIALS Isolation of Brown Fat CellsBrown fat cells were isolated by a method similar to that described by Fain et al. [19]. Two important modifications were introduced into the isolation procedure. First, hamsters were starved for 48 to 72 h prior to sacrifice in order to reduce the size of the lipid globules within the cells. Analyses of extractable lipids from rat brown fat show a 40°/, reduction of lipid after 48 h of starvation [21]. Second, micro-hematocrit determinations of the cell volume in the final suspension were made in order to allow adjustment of the suspension concentration prior to experimentation.Adult hamsters, more than 60 days old, weighing 70-105 g, were killed by guillotine to minimize the

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“…Fine-structure studies by Nechad and Barnard (1979) and an earlier light microscope investigation by Smalley and Smalley (1967) on developing BAT in the hamster produced essentially similar speculations on the likely capillary endothelial or paravascular mesenchymal origins for adipocytes following the observation of "immature brown adipocytes" closely associated with blood vessels at 3-5 days of age. At first characterized as unilocular because of their possession of single lipid droplets, these "immature brown adipocytes" became increasingly multilocular in appearance such that, at 15 days of age, the majority of parenchyma1 cells in BAT were multilocular.…”

Section: Precursor Cells In Embryonic and Perinatal Adipose Tissuesmentioning

confidence: 64%

Development of adipose tissues

Nnodim

1987

Anat. Rec.

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Studies on the development of brown and white adipose tissues and their relationship to ordinary connective tissue are the subject of the present review, which is updated to the fall of 1985. Primordial entities described as "primitive organs" have been noted at sites of adipose tissue development by numerous investigators. These "primitive organs" are clearly delineated from surrounding connective tissue and possess a well-defined vascular network in the interstices of which cellular organization takes place. The precursor cells of brown and white adipocytes appear to acquire their distinctive cytogenetic properties at a very early stage in the embryo. These progenitor cells temporarily exhibit structural similarities to fibroblasts and endothelial cells. This resemblance has led to speculation that fibroblasts and/or endothelial cells may be ancestral to adipocytes. However, recent in vivo and in vitro observations suggest that the brown adipose precursor cell is morphogenetically distinct from the white adipose precursor cell on one hand, and from fibroblasts and endothelial cells on the other. In vitro studies have also shown that the pericytic elements present in both brown and white adipose tissue depots in the adult are quiescent precursor cells that may be recruited under certain circumstances. Areas for further inquiry by means of recently developed techniques are indicated.

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Brown and White Fats: Development in the Hamster

Cited by 20 publications

References 8 publications

Brown Fat Thermoregulation in Developing Hamsters (<i>Mesocricetus auratus</i>): a GDP-Binding Study

Brown Fat Thermoregulation in Developing Hamsters (<i>Mesocricetus auratus</i>): a GDP-Binding Study

Oxidative Metabolism in Cells Isolated from Brown Adipose Tissue

Development of adipose tissues

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