A dramatic accumulation of glycogen in the brown adipose tissue of rats following recovery from cold exposure

In a morphological study of brown adipose tissue (BAT) of rats returned after exposure to cold (+5 degrees C) to neutral temperature (+25 degrees C), striking periodic acid Schiff staining was observed, indicating substantial glycogen accumulation. Enzymatic analysis revealed that the glycogen content increased from the 4.05 +/- 0.51 (micromol glucose unit per gram of tissue, mean +/- SE) control value to 57.3 +/- 9.66 when the animals were returned to neutral temperature for 24 h after a 1-week cold period. Glycogen repletion was also observed in liver and skeletal muscle; however, the glycogen levels in these tissues never exceeded the control values. The accumulation of glycogen in the BAT started by the 3rd hour of replacement and peaked by the 24th hour. This glycogen was readily utilized during the next short cold exposure of the animals. The plasma leptin concentration was reduced at the cold temperature. The hexokinase II activity in the BAT increased to 29.3 +/- 1.46 vs the 11.8 +/- 1.06 control (mU/mg protein +/- SE) after a 1-week cold exposure and this level was maintained during the return to neutral temperature. The total glycogen synthetase (GStot) and the glycogen synthetase a activity also increased after a 1-week cold exposure and increased further during the replacement. The level of GStot reached 26.9 +/- 1.39 vs 9.54 +/- 1.43 control by the 24th hour of replacement. At the same time, the glycogen phosphorylase a activity declined during the replacement. The concentration of glucose 6-phosphate (an activator of GS) decreased in the cold but returned to normal during the replacement. These changes in the BAT are in favor of glycogen synthesis.     

CYTOLOGICAL RESPONSES OF BROWN FAT TISSUE IN COLD-EXPOSED RATS

In young adult laboratory rats exposed to cold (6°C) the brown adipose tissue undergoes time-dependent increases in cellularity, vascular supply, and total mass. These changes are largely complete after 16 days in the cold and concurrent generally with the development of a thermoregulatory state not greatly dependent upon shivering. Histologically the brown fat changes from a tissue having both unilocular and multilocular fat cell types to one having almost exclusively the latter. During the first 6 to 12 hours in cold, the multilocular cells lose their lipid vacuoles and decrease in size, but these features are restored to normal by 24 hours. Cell proliferation, as estimated by the DNA synthetic index method (using tritiated thymidine autoradiography), appears in the reticuloendothelial cells of the brown fat at 1 day of cold exposure, becomes maximal at 4 days, and returns to the control level by 16 days. In animals injected with tritiated thymidine on the 3rd day of cold exposure and then maintained for 1 or more additional days in the cold, autoradiographs indicate that new brown fat (multilocular) cells arise by cytogenesis from reticuloendothelial progenitor cells and not by proliferation of existing brown fat cells. Throughout this and subsequent periods, cells of the epididymal white adipose tissue slowly decrease in size. Because a thermogenic role in cold acclimation has been established for the brown fat, the reported changes are regarded as adaptive responses to a cold environment.     

Cyclic GMP and cyclic GMP-dependent protein kinase in brown adipose tissue of developing rats

In order to ascertain the possible involvement of cyclic GMP in the physiological regulation of the function and development of brown fat of the rat, we have determined its tissue concentration in vivo under a variety of conditions. The steady-state concentration of cyclic GMP in interscapular brown adipose tissue of late foetus was about 80 pmol per g fresh weight. The concentration gradually declined during the first 2 weeks after birth to reach 40 pmol/g fresh weight and then remained constant into adulthood. The cyclic GMP content of brown fat was decreased by chemical sympathectomy and was increased after complete acclimatization of the animals to the cold. The activity of cyclic GMP-dependent protein kinase was also highest in tissue from newborn and cold-acclimatized rats.Both acute cold stress and injection of norepinephrine resulted in a significant but temporary increase in the concentration of cyclic GMP in brown fat, which was followed by a depression of the concentration below values in untreated animals. The concentration of cyclic AMP showed similar pattern of changes. Injection of phenylephrine was followed by a pronounced increase in the cyclic GMP content of brown fat, with little effect upon cyclic AMP. Injection of isoproterenol raised the content of cyclic AMP but not that of cyclic GMP. The ability of norepinephrine and phenylephrine to increase the concentration of cyclic GMP was abolished by pre-treatment of the animals with phenoxybenzamine, but not by pre-treatment with propranolol. Conversely, propranolol but not phenoxybenzamine abolished the effects of norepinephrine on the cyclic AMP content of the tissue.Thus we have established the responsiveness of the cyclic GMP content of brown fat to physiological and pharmacological stimuli and have evidence of the possible participation by cyclic GMP in the α-adrenergic stimulation and in the regulation of proliferative processes in the tissue.     

UCP1-independent thermogenesis in white adipose tissue of cold-acclimated Ucp1-/- mice

Apart from UCP1-based nonshivering thermogenesis in brown adipocytes, the identity of thermogenic mechanisms that can be activated to reduce a positive energy balance is largely unknown. To identify potentially useful mechanisms, we have analyzed physiological and molecular mechanisms that enable mice, genetically deficient in UCP1 and sensitive to acute exposure to the cold at 4 degrees C, to adapt to long term exposure at 4 degrees C. UCP1-deficient mice that can adapt to the cold have increased oxygen consumption and show increased oxidation of both fat and glucose as indicated from serum metabolite levels and liver glycogen content. Enhanced energy metabolism in inguinal fat was also indicated by increased oxygen consumption and fat oxidation in tissue suspensions and increased AMP kinase activity in dissected tissues. Analysis of gene expression in skeletal muscle showed surprisingly little change between cold-adapted Ucp1+/+ and Ucp1-/- mice, whereas in inguinal fat a robust induction occurred for type 2 deiodinase, sarcoendoplasmic reticulum Ca2+-ATPase, mitochondrial glycerol 3-phosphate dehydrogenase, PGC1alpha, CoxII, and mitochondrial DNA content. Western blot analysis showed an induction of total phospholamban and its phosphorylated form in inguinal fat and other white fat depots, but no induction was apparent in muscle. We conclude that alternative thermogenic mechanisms, based in part upon the enhanced capacity for ion and substrate cycling associated with brown adipocytes in white fat depots, are induced in UCP1-deficient mice by gradual cold adaptation.     

Portein kinases in brown adipose tissue of developing rats. State of activation of protein kinase during development and cold exposure and its relationship to adenosine 3':5'-monophosphate, lipolysis, and heat production.

The addition of norepinephrine to brown fat in vitro produced a dose-dependent increase in the protein kinase activity ratio (the ratio of activity assayed without cAMP to that assayed with cAMP) in extracts subsequently prepared in the presence of 0.5 M NaCl. The ratio was slightly increased by insulin. The effects of norepinephrine were potentiated by theophylline and reduced by propranolol. There was a significant linear regression between protein kinase activity ratio and the rate of glycerol release for ratios between 0.32 and 0.52. Higher activity ratios were associated with a slight but nonsignificant increase in glycerol release. The relationship between the protein kinase activity ratio and the concentration of cAMP in brown fat could be expressed by simple saturation kinetics. There was a significant linear regression between the reciprocal of the concentration of cAMP in the tissue and the reciprocal of the activity ratio over the whole range of observed values. Exposure of 1-month-old rats to cold increased the protein kinase activity ratio in their brown fat. This confirms that activation of protein kinase is involved in the physiological response of a tissue to a specific environmental stimulus. As the rat became fully adapted to the cold, the activity ratio declined. The protein kinase activity ratio in brown fat was low in late fetuses but greatly increased immediately after birth and remained high for the next 2 weeks. During this period the ratio was not further increased by the injection of norepinephrine but was reduced after chemical sympathectomy. The activity ratio in brown fat fell during the 3rd and 4th weeks after birth. At this time injection of norepinephrine increased the ratio whereas chemical sympathectomy had little effect. These observations confirm that the stimulation of the tissue by the sympathetic nerves results in an activation of protein kinase and reflect the reduced requirement for heat production in brown fat as the animals grow.     

Increased contribution of brown adipose tissue to nonshivering thermogenesis in the Djungarian hamster during cold-adaptation

Summary The effect of cold-adaptation was investigated on the brown adipose tissue of Djungarian hamsters. Animals maintained at 23°C and 16 hours light per day (controls) were exposed to 5°C. The wet weight of the total brown fat is reduced by some 40% within 4 days of coldexposure, as a result of extensive triacylglycerol depletion of the tissue with no reduction in DNA; the tissue mass remains constant unde persistent cold influence. The total amount of tissue mitochondria is doubled by 24 h and increases by a factor of 3 under persistent cold-stimulus, the specific respiratory capacity of the organelles remaining unchanged. The amount of 32 kDa regulatory protein per mg mitochondrial protein quantified from high-affinity GDP-binding, is increased by a factor of 2.7 after 21 days of cold-adaptation; a 9-fold increment is found of the total mitochondrial GDB-binding capacity.Comparison of nonshivering thermogenesis and the maximal thermogenic capacity of brown fat, estimated from the maximal respiration of the isolated mitochondria and the total amount of mitochondria in the tissue, suggests that brown fat may contribute about 20% to the whole-body nonshivering thermogenesis in warm-adapted controls and 45% in cold-adapted hamsters. The estimated increase in thermogenic capacity of the tissue in response to 21 days of cold-adaptation corresponds to the increase in nonshivering thermogenesis, suggesting a central thermoregulatory role of brown fat during cold-adaptation.Abbreviation FCCP carbonylcyanide-p-trifluoromethoxyphenylhydrazone     

Partial restoration of dietary fat induced metabolic adaptations to training by 7 days of carbohydrate diet.

We tested the hypothesis that a shift to carbohydrate diet after prolonged adaptation to fat diet would lead to decreased glucose uptake and impaired muscle glycogen breakdown during exercise compared with ingestion of a carbohydrate diet all along. We studied 13 untrained men; 7 consumed a high-fat (Fat-CHO; 62% fat, 21% carbohydrate) and 6 a high-carbohydrate diet (CHO; 20% fat, 65% carbohydrate) for 7 wk, and thereafter both groups consumed the carbohydrate diet for an eighth week. Training was performed throughout. After 8 wk, during 60 min of exercise (71 +/- 1% pretraining maximal oxygen uptake) average leg glucose uptake (1.00 +/- 0.07 vs. 1.55 +/- 0.21 mmol/min) was lower (P < 0.05) in Fat-CHO than in CHO. The rate of muscle glycogen breakdown was similar (4.4 +/- 0.5 vs. 4.2 +/- 0.7 mmol. min(-1). kg dry wt(-1)) despite a significantly higher preexercise glycogen concentration (872 +/- 59 vs. 688 +/- 43 mmol/kg dry wt) in Fat-CHO than in CHO. In conclusion, shift to carbohydrate diet after prolonged adaptation to fat diet and training causes increased resting muscle glycogen levels but impaired leg glucose uptake and similar muscle glycogen breakdown, despite higher resting levels, compared with when the carbohydrate diet is consumed throughout training.     

SOME FACTORS INFLUENCING BRAIN GLYCOGEN IN THE NEONATE CHICK

—Studies of the brain glycogen concentration in the chick during the perinatal period showed that there was an increase immediately prior to hatching. This was followed by a pronounced decrease between 1 and 2 days after hatching. The decrease was most marked in the cerebellum. During ischaemia, the rate of glycogen depletion was greater in 1-day-old chicks than in 2- and 7-day-old birds. Brain glycogen concentration exhibited a circadian rhythm which was not closely related to changes in motor activity or body temperature. Exposure to a high environmental temperature (40°C) caused a depletion of glycogen, but exposure to a low temperature (2°C) had no effect. Four hours of hyperglycaemia resulted in a lowering of brain glycogen levels whereas hypoglycaemia was without effect.     

Aspect ultrastructural de la lipogénèse dans le tissu adipeux brun

Summary In interscapular brown fat of the rat, appropriately processed so as to maintain membrane structures intact, lipid droplets are in fact liposomes, i.e., lipid filled vacuoles surrounded by a membrane that is related to the smooth endoplasmic reticulum. Thus the endoplasmic reticulum appears as an important component of brown fat cells. — After complete lipid depletion has been achieved by 7 days of fasting, feeding with glucose results in sudden and very conspicuous increase of smooth endoplasmic reticulum; dilatations of the perinuclear cistern and pinocytotic activity at the periphery of the cell contribute to this increase. Simultaneously the cytoplasmic matrix is heavily loaded with glycogen in particulate form. Lipogenesis, as far as can be appreciated by different degrees in electron density, takes place inside the vesicles of the endoplasmic reticulum; increase of such small lipid vacuoles then leads to reconstitution of liposomes; return to the normal aspect is completed 12 hours after the beginning of feeding. — During the phase of glycogen overloading and resulting lipogenesis, glycogen particles may be found in intercellular and pericapillary spaces; the significance of this finding is discussed. — The fundamental difference between both types of fat cells seems to be concerned with the site of lipogenesis: this takes place in the cytoplasmic matrix of white fat cells, so that lipid droplets aggregate without any limiting membrane, whereas in brown fat cells lipogenesis occurs inside cavities of the endoplasmic reticulum and lipids remain permanently enclosed in membranes. This process appears similar to what may be observed occasionally in liver and normally in adrenal cortex, and this might presumably lead to a physico-chemical understanding of the particular aspect of lipogenesis in brown fat, as compared to that in common white fat.

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Travail dédié au Professeur W. Bargmann, en témoignage d'admiration, à l'occasion de son 60e anniversaire.     

The development of insulin resistance in brown adipose tissue may impair the acute cold-induced activation of thermogenesis in genetically obese (ob/ob) mice

Genetically obese (ob/ob) mice develop insulin resistance in brown adipose tissue during the fifth week of life. Prior to this, at 26 days of age, oh/oh mice show a substantial increase in GDP binding to brownadipose-tissue mitochondria during acute cold exposure. When insulin resistance in brown fat develops, by 35 days of age, the increase in GDP binding in response to cold is markedly reduced. Studies with 2-deoxyglucose suggest that insulin resistance in brown adipose tissue could impair thermogenic responsiveness during acute cold exposure by limiting the ability of the tissue to take up glucose.     

Manipulation of dietary carbohydrate and muscle glycogen affects glucose uptake during exercise when fat oxidation is impaired by beta-adrenergic blockade

We have recently reported that, during moderate intensity exercise, low muscle glycogen concentration and utilization caused by a high-fat diet is associated with a marked increase in fat oxidation with no effect on plasma glucose uptake (R(d) glucose). It is our hypothesis that this increase in fat oxidation compensates for low muscle glycogen, thus preventing an increase in R(d) glucose. Therefore, the purpose of this study was to determine whether low muscle glycogen availability increases R(d) glucose under conditions of impaired fat oxidation. Six cyclists exercised at 50% peak O(2) consumption (Vo(2 peak)) for 1 h after 2 days on either a high-fat (HF, 60% fat, 24% carbohydrate) or control (CON, 22% fat, 65% carbohydrate) diet to manipulate muscle glycogen to low and normal levels, respectively. Two hours before the start of exercise, subjects ingested 80 mg of propanolol (betaB), a nonselective beta-adrenergic receptor blocker, to impair fat oxidation during exercise. HF significantly decreased calculated muscle glycogen oxidation (P < 0.05), and this decrease was partly compensated for by an increase in fat oxidation (P < 0.05), accompanied by an increase in whole body lipolysis (P < 0.05), despite the presence of betaB. Although HF increased fat oxidation, plasma glucose appearance rate, R(d) glucose, and glucose clearance rate were also significantly increased by 13, 15, and 26%, respectively (all P < 0.05). In conclusion, when lipolysis and fat oxidation are impaired, in this case by betaB, fat oxidation cannot completely compensate for a reduction in muscle glycogen utilization, and consequently plasma glucose turnover increases. These findings suggest that there is a hierarchy of substrate compensation for reduced muscle glycogen availability after a high-fat, low-carbohydrate diet, with fat being the primary and plasma glucose the secondary compensatory substrate. This apparent hierarchy likely serves to protect against hypoglycemia when endogenous glucose availability is low.     

Cold exposure does not decrease serum leptin concentration,but increases energy intake and thermogenic capacity in pregnant Brandt's voles (Lasiopodomys brandtii)

In most mammals, maternal body mass and fat mass increase during pregnancy due to hyperphagia. These physiological changes provide the fetus with energy and nutrients and prepare the mother for the high energetic demands of lactation. In the present study, metabolic changes in response to cold and pregnancy were examined in female Brandt's voles (Lasiopodomys brandtii). At 23±1 °C, the voles increased body mass and deposited body fat during pregnancy. However, at 5±1 °C pregnant voles did not deposit body fat even though energy intake increased above the level in the warm. Serum leptin concentration increased during pregnancy and was not influenced by cold exposure. Thermogenic capacity, as indicated by uncoupling protein 1 (UCP1) content in brown adipose tissue (BAT), increased in cold-exposed pregnant voles. The number and mass of fetuses were not affected by cold exposure. Our data may indicate the importance of an increased serum leptin concentration for a successful outcome of the pregnancy and also the independence of leptin secretion from body fat in pregnant voles. It also implies the need to develop central leptin resistance with respect to control of energy balance for pregnant voles.     

Effect of noradrenaline chronic administration on brown fat phospholipids

Chronic cold exposure of rats (9 days at 5°C) induces an alteration of the fatty acid composition of phospholipids in brown adipose tissue. The alteration is due to an increase of the unsaturation degree of these lipids. The phenomenon can be reproduced by 10^–7 mole. h^–1 administration of noradrenaline for 9 days in rats kept at 25°C. Thus, phospholipid alteration in brown fat of cold exposed rats is most probably a consequence of the increase of sympathetic tone which occurs in this tissue during exposure to cold.     

Muscle glycogen availability and temperature regulation in humans

The effects of intramuscular glycogen availability on human temperature regulation were studied in eight seminude subjects immersed in 18 degrees C water for 90 min or until rectal temperature (Tre) decreased to 35.5 degrees C. Each subject was immersed three times over a 3-wk period. Each immersion followed 2.5 days of a specific dietary and/or exercise regimen designed to elicit low (L), normal (N), or high (H) glycogen levels in large skeletal muscle groups. Muscle glycogen concentration was determined in biopsies taken from the vastus lateralis muscle before and after each immersion. Intramuscular glycogen concentration before the immersion was significantly different among the L, N, and H trials (P less than 0.01), averaging 247 +/- 15, 406 +/- 23, and 548 +/- 42 (SE) mmol glucose units.kg dry muscle-1, respectively. The calculated metabolic heat production during the first 30 min of immersion was significantly lower during L compared with N or H (P less than 0.05). The rate at which Tre decreased was more rapid during the L immersion than either N or H (P less than 0.05), and the time during the immersion at which Tre first began to decrease also appeared sooner during L than N or H. The results suggest that low skeletal muscle glycogen levels are associated with more rapid body cooling during water immersion in humans. Higher than normal muscle glycogen levels, however, do not increase cold tolerance.     

Hypothalamic temperature and thermogenesis of brown fat during desynchronized sleep in rats

The relationship between hypothalamic temperature and deep interscapular temperature measured just below the brown fat lobes has been studied during desynchronized sleep at two ambient temperatures (24 degrees C and 4 degrees C) before and after adaptation (9 days) to cold (4 degrees C). The results show that the increase in hypothalamic temperature during this stage of sleep occurs independently of a transfer of heat from interscapular brown fat.     

Carbohydrate metabolism in starved fifth instar larvae of Manduca sexta

The influence of starvation on carbohydrate metabolism in fifth instar larvae of Manduca sexta was studied. The percentage of active fat body glycogen phosphorylase increased from 10% to approximately 50% within 3 h of starvation; afterward the enzyme was slowly inactivated. The increase of phosphorylase activity might have been caused by a peptide(s) from the CC. The amount of fat body glycogen in starved animals decreased over 24 h by approximately 20 mg. The released glucose molecules seem to be converted mainly to trehalose because the hemolymph trehalose concentration in starved animals was always slightly higher than in the fed controls, and the glucose concentration decreased even when phosphorylase was activated. The chitosan content in starved larvae increased during the first 9 h of treatment to the same extent as in fed controls. It is suggested that fat body glycogen phosphorylase was activated during starvation to provide substrates for chitin synthesis and energy metabolism.     

Carbohydrate metabolism during starvation in the silkworm Bombyx mori

The effect of starvation on carbohydrate metabolism in the last instar larvae of the silkworm Bombyx mori was examined. Trehalose concentration in the hemolymph increased slightly during the first 6 h of starvation and decreased thereafter, whereas glucose concentration decreased rapidly immediately after diet deprivation. Starvation-induced hypertrehalosemia was completely inhibited by neck ligation, suggesting that starvation stimulates the release of a hypertrehalosemic factor(s) from the head. The percentage of active glycogen phosphorylase in the fat body increased within 3 h of starvation and its glycogen content decreased gradually. These observations suggest that production of trehalose from glycogen is enhanced in starved larvae. However, hypertrehalosemia during starvation cannot be explained by the increased supply of trehalose into hemolymph alone, as similar changes in phosphorylase activity and glycogen content in the fat body were observed in neck-ligated larvae, in which hemolymph trehalose concentration did not increase but decreased gradually. When injected into larvae, trehalose disappeared from hemolymph at a rate about 40% lower in starved larvae than neck-ligated larvae. The hemolymph lipid concentration increased during starvation, suggesting that an increased supply of lipids to tissues suppresses the consumption of hemolymph trehalose and this is an important factor in hypertrehalosemia.     

Effects of endurance exercise training on muscle glycogen accumulation in humans.

The purpose of this investigation was to determine whether endurance exercise training increases the ability of human skeletal muscle to accumulate glycogen after exercise. Subjects (4 women and 2 men, 31 +/- 8 yr old) performed high-intensity stationary cycling 3 days/wk and continuous running 3 days/wk for 10 wk. Muscle glycogen concentration was measured after a glycogen-depleting exercise bout before and after endurance training. Muscle glycogen accumulation rate from 15 min to 6 h after exercise was twofold higher (P < 0.05) in the trained than in the untrained state: 10.5 +/- 0.2 and 4.5 +/- 1.3 mmol. kg wet wt(-1). h(-1), respectively. Muscle glycogen concentration was higher (P < 0.05) in the trained than in the untrained state at 15 min, 6 h, and 48 h after exercise. Muscle GLUT-4 content after exercise was twofold higher (P < 0.05) in the trained than in the untrained state (10.7 +/- 1.2 and 4.7 +/- 0.7 optical density units, respectively) and was correlated with muscle glycogen concentration 6 h after exercise (r = 0.64, P < 0.05). Total glycogen synthase activity and the percentage of glycogen synthase I were not significantly different before and after training at 15 min, 6 h, and 48 h after exercise. We conclude that endurance exercise training enhances the capacity of human skeletal muscle to accumulate glycogen after glycogen-depleting exercise.     

Low-fat diet alters intramuscular substrates and reduces lipolysis and fat oxidation during exercise

We determined whether a low-fat diet reduces intramuscular triglyceride (IMTG) concentration, whole body lipolyis, total fat oxidation, and calculated nonplasma fatty acid (FA) oxidation during exercise. Seven endurance-trained cyclists were studied over a 3-wk period during which time they exercised 2 h/day at 70% of maximum O2 uptake VO(2 max) and consumed approximately 4,400 kcal/day. During the 1st wk, their fat intake provided 32% of energy. During the 2nd and 3rd wk, they were randomly assigned to eat 2 or 22% of energy from fat (2%FAT or 22%FAT). Compared with 22%FAT, 2%FAT lowered IMTG concentration and raised muscle glycogen concentration at rest (P < 0.05). Metabolism was studied during 1 h of exercise at 67% VO(2 max) performed in the fasted state. 2%FAT resulted in a 27% reduction (P < 0.05) in total fat oxidation vs. 22%FAT without altering the stable isotopically determined rates of plasma free fatty acid or glucose disappearance. Therefore, 2%FAT reduced calculated nonplasma FA oxidation by 40% in association with a 19% reduction in whole body lipolysis while increasing calculated minimal muscle glycogen oxidation compared with 22%FAT (all P < 0.05). In summary, an extremely low fat (2% of energy) and high-carbohydrate diet lowers whole body lipolysis, total fat oxidation, and nonplasma FA oxidation during exercise in the fasted state in association with a reduced concentration of intramuscular triglyceride.     

Inherent plasticity of brown adipogenesis in white fat of mice allows for recovery from effects of post-natal malnutrition

Interscapular brown adipose tissue (iBAT) is formed during fetal development and stable for the life span of the mouse. In addition, brown adipocytes also appear in white fat depots (wBAT) between 10 and 21 days of age in mice maintained at a room temperature of 23 °C. However, this expression is transient. By 60 days of age the brown adipocytes have disappeared, but they can re-emerge if the adult mouse is exposed to the cold (5 °C) or treated with β3-adrenergic agonists. Since the number of brown adipocytes that can be induced in white fat influences the capacity of the mouse to resist the obese state, we determined the effects of the nutritional conditions on post-natal development (birth to 21 days) of wBAT and its long-term effects on diet-induced obesity (DIO). Under-nutrition caused essentially complete suppression of wBAT in inguinal fat at 21 days of age, as indicated by expression of Ucp1 and genes of mitochondrial structure and function based upon microarray and qRT-PCR analysis, whereas over-nutrition had no discernible effects on wBAT induction. Surprisingly, the suppression of wBAT at 21 days of age did not affect DIO in adult mice maintained at 23 °C, nor did it affect the reduction in obesity or cold tolerance when DIO mice were exposed to the cold at 5 °C for one week. Gene expression analysis indicated that mice raised under conditions that suppressed wBAT at 21 days of age were able to normally induce wBAT as adults. Therefore, neither severe hypoleptinemia nor hypoinsulinemia during suckling permanently impaired brown adipogenesis in white fat. In addition, energy balance studies of DIO mice exposed to cold indicates that mice with reduced adipose stores preferentially increased food intake, whereas those with larger adipose tissue depots preferred to utilize energy from their adipose stores.