1
|
Agea I, García ML, Blasco A, Argente MJ. Litter Survival Differences between Divergently Selected Lines for Environmental Sensitivity in Rabbits. Animals (Basel) 2019; 9:ani9090603. [PMID: 31450706 PMCID: PMC6769716 DOI: 10.3390/ani9090603] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 08/14/2019] [Accepted: 08/20/2019] [Indexed: 11/23/2022] Open
Abstract
Simple Summary Two rabbit lines are divergently selected for increasing or decreasing the variability of litter size at birth. Decreasing the litter size variability produces more resilient females with less sensitivity to diseases, being an indirect selection way to improve environmental sensitivity. The kits’ survival rate at weaning was higher in the homogeneous line. Moreover, this line led to a greater uniformity of the kits’ weight at weaning, although the weight variability at birth was higher, which could be due to a higher lactation capacity of the homogeneous line. Abstract A divergent selection experiment on environmental sensitivity was performed in rabbits. The aim was to estimate the correlated response in kit weight and survival, litter weight, and weight distance from birth to weaning. The weight distance was calculated as the absolute value of the differences between the individual value and the mean value of its litter. The relationship between the probability of survival at 4 d of age, and the weight at birth, was studied. Environmental sensitivity was measured as litter size variability. A total of 2484 kits from 127 does from the low line, and 1916 kits of 114 does from the high line of the 12th generation were weighed. Both of the lines showed similar individual and litter weights at birth and weaning, and a similar survival rate at birth, and at 4 d of age. The survival rate at weaning was higher in the low line (0.67 and 0.62; P = 0.93). The weight distance was higher at birth, but lower at weaning in the low line (47.8 g and 54.1 g; P = 0.98). When the weight at birth was high, the kits had a higher survival rate. In conclusion, selection for environmental sensitivity showed a correlated response in the kits’ survival, and in the homogeneity of litter weight at weaning.
Collapse
Affiliation(s)
- Ivan Agea
- Departamento de Tecnología Agroalimentaria, Universidad Miguel Hernández de Elche, Ctra de Beniel Km 3.2, 03312 Orihuela, Spain
| | - María-Luz García
- Departamento de Tecnología Agroalimentaria, Universidad Miguel Hernández de Elche, Ctra de Beniel Km 3.2, 03312 Orihuela, Spain.
| | - Agustín Blasco
- Institute for Animal Science and Technology, Universitat Politècnica de València, P.O. Box 22012, 46022 Valencia, Spain
| | - María-José Argente
- Departamento de Tecnología Agroalimentaria, Universidad Miguel Hernández de Elche, Ctra de Beniel Km 3.2, 03312 Orihuela, Spain
| |
Collapse
|
2
|
Goody D, Pfeifer A. MicroRNAs in brown and beige fat. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:29-36. [DOI: 10.1016/j.bbalip.2018.05.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 02/05/2018] [Accepted: 05/04/2018] [Indexed: 12/27/2022]
|
3
|
Abstract
A new study in Nature Medicine, by Ikeda et al. (2017), reports that calcium cycling in beige adipocytes elevates energy expenditure and glucose oxidation in the absence of uncoupling protein 1. Thermogenic calcium cycling in beige fat is mediated by SERCA2b and improves cold tolerance and metabolic status.
Collapse
|
4
|
Bautista A, Zepeda JA, Reyes-Meza V, Féron C, Rödel HG, Hudson R. Body mass modulates huddling dynamics and body temperature profiles in rabbit pups. Physiol Behav 2017; 179:184-190. [DOI: 10.1016/j.physbeh.2017.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/10/2017] [Accepted: 06/10/2017] [Indexed: 10/19/2022]
|
5
|
Blix AS. Adaptations to polar life in mammals and birds. ACTA ACUST UNITED AC 2017; 219:1093-105. [PMID: 27103673 DOI: 10.1242/jeb.120477] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 01/25/2016] [Indexed: 12/22/2022]
Abstract
This Review presents a broad overview of adaptations of truly Arctic and Antarctic mammals and birds to the challenges of polar life. The polar environment may be characterized by grisly cold, scarcity of food and darkness in winter, and lush conditions and continuous light in summer. Resident animals cope with these changes by behavioural, physical and physiological means. These include responses aimed at reducing exposure, such as 'balling up', huddling and shelter building; seasonal changes in insulation by fur, plumage and blubber; and circulatory adjustments aimed at preservation of core temperature, to which end the periphery and extremities are cooled to increase insulation. Newborn altricial animals have profound tolerance to hypothermia, but depend on parental care for warmth, whereas precocial mammals are well insulated and respond to cold with non-shivering thermogenesis in brown adipose tissue, and precocial birds shiver to produce heat. Most polar animals prepare themselves for shortness of food during winter by the deposition of large amounts of fat in times of plenty during autumn. These deposits are governed by a sliding set-point for body fatness throughout winter so that they last until the sun reappears in spring. Polar animals are, like most others, primarily active during the light part of the day, but when the sun never sets in summer and darkness prevails during winter, high-latitude animals become intermittently active around the clock, allowing opportunistic feeding at all times. The importance of understanding the needs of the individuals of a species to understand the responses of populations in times of climate change is emphasized.
Collapse
Affiliation(s)
- Arnoldus Schytte Blix
- Department of Arctic Biology, University of Tromsø, Tromsø 9037, Norway St Catharine's College, Cambridge CB2 1RL, UK
| |
Collapse
|
6
|
Rödel HG, Bautista A, Roder M, Gilbert C, Hudson R. Early development and the emergence of individual differences in behavior among littermates of wild rabbit pups. Physiol Behav 2017; 173:101-109. [DOI: 10.1016/j.physbeh.2017.01.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/17/2017] [Accepted: 01/30/2017] [Indexed: 12/21/2022]
|
7
|
Affiliation(s)
- David Hull
- Pwdiatric Department, Radcliffe Infirmary, Oxford
| |
Collapse
|
8
|
Differential metabolism of brown adipose tissue in newborn rabbits in relation to position in the litter huddle. J Therm Biol 2015; 51:33-41. [DOI: 10.1016/j.jtherbio.2015.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 12/20/2022]
|
9
|
Abstract
PURPOSE OF REVIEW New evidence has recently supported the notion that brown adipose tissue (BAT) is present in adult humans and can play a prominent role in the regulation of body weight and metabolism. This has renewed the efforts to understand the physiologic mechanisms by which BAT is activated, which in turn could provide new therapeutic strategies for obesity and diabetes. RECENT FINDINGS BAT mass and activity are positively correlated with measures of metabolic health in rodents and humans; however, the amount of functional BAT in adult humans is highly variable with less found in overweight and obese individuals. The impact of BAT in the uptake and utilization of circulating nutrients is systemic, with major effects on whole-body insulin sensitivity and glucose tolerance as illustrated by BAT transplantation in rodents. Furthermore, a host of physiologic conditions and novel peptides/hormones have been implicated in the activation of BAT thermogenesis and/or 'browning' of white adipocytes. SUMMARY These new findings open the way for novel strategies aimed at increasing BAT mass and activity in obese humans as an important clinical goal in the midst of unprecedented high prevalence of obesity and associated metabolic disorders.
Collapse
Affiliation(s)
- Christine Loyd
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati, Cincinnati, Ohio, USA
| | | |
Collapse
|
10
|
Hu HH, Wu TW, Yin L, Kim MS, Chia JM, Perkins TG, Gilsanz V. MRI detection of brown adipose tissue with low fat content in newborns with hypothermia. Magn Reson Imaging 2013; 32:107-17. [PMID: 24239336 DOI: 10.1016/j.mri.2013.10.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/05/2013] [Accepted: 10/08/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To report the observation of brown adipose tissue (BAT) with low fat content in neonates with hypoxic-ischemic encephalopathy (HIE) after they have undergone hypothermia therapy. MATERIALS AND METHODS The local ethics committee approved the imaging study. Ten HIE neonates (3 males, 7 females, age range: 2-3days) were studied on a 3-T MRI system using a low-flip-angle (3°) six-echo proton-density-weighted chemical-shift-encoded water-fat pulse sequence. Fat-signal fraction (FF) measurements of supraclavicular and interscapular (nape) BAT and adjacent subcutaneous white adipose tissues (WAT) were compared to those from five non-HIE neonates, two recruited for the present investigation and three from a previous study. RESULTS In HIE neonates, the FF range for the supraclavicular, interscapular, and subcutaneous regions was 10.3%-29.9%, 28.0%-57.9%, and 62.6%-88.0%, respectively. In non-HIE neonates, the values were 23.7%-42.2% (p=0.01), 45.4%-59.5% (p=0.06), and 67.8%-86.3% (p=0.38), respectively. On an individual basis, supraclavicular BAT FF was consistently the lowest, interscapular BAT values were higher, and subcutaneous WAT values were the highest (p<0.01). CONCLUSION We speculate that hypothermia therapy in HIE neonates likely promotes BAT-mediated non-shivering thermogenesis, which subsequently leads to a depletion of the tissue's intracellular fat stores. We believe that this is consequently reflected in lower FF values, particularly in the supraclavicular BAT depot, in contrast to non-HIE neonates.
Collapse
Affiliation(s)
- Houchun H Hu
- Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA.
| | - Tai-Wei Wu
- Neonatology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Larry Yin
- Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Mimi S Kim
- Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | | | | | - Vicente Gilsanz
- Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA; Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA, USA
| |
Collapse
|
11
|
Bautista A, Castelán F, Pérez-Roldán H, Martínez-Gómez M, Hudson R. Competition in newborn rabbits for thermally advantageous positions in the litter huddle is associated with individual differences in brown fat metabolism. Physiol Behav 2013; 118:189-94. [DOI: 10.1016/j.physbeh.2013.05.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 02/02/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
|
12
|
Carey AL, Kingwell BA. Brown adipose tissue in humans: therapeutic potential to combat obesity. Pharmacol Ther 2013; 140:26-33. [PMID: 23718981 DOI: 10.1016/j.pharmthera.2013.05.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 05/09/2013] [Indexed: 01/19/2023]
Abstract
Harnessing the considerable capacity of brown adipose tissue (BAT) to consume energy was first proposed as a potential target to control obesity nearly 40years ago. The plausibility of this approach was, however, questioned due to the prevailing view that BAT was either not present or not functional in adult humans. Recent definitive identification of functional BAT in adult humans as well as a number of important advances in the understanding of BAT biology has reignited interest in BAT as an anti-obesity target. Proof-of-concept evidence demonstrating drug-induced BAT activation provides an important foundation for development of targeted pharmacological approaches with clinical application. This review considers evidence from both human and relevant animal studies to determine whether harnessing BAT for the treatment of obesity via pharmacological intervention is a realistic goal.
Collapse
Affiliation(s)
- Andrew L Carey
- Metabolic and Vascular Physiology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
| | | |
Collapse
|
13
|
Private heat for public warmth: how huddling shapes individual thermogenic responses of rabbit pups. PLoS One 2012; 7:e33553. [PMID: 22438947 PMCID: PMC3306396 DOI: 10.1371/journal.pone.0033553] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 02/16/2012] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Within their litter, young altricial mammals compete for energy (constraining growth and survival) but cooperate for warmth. The aim of this study was to examine the mechanisms by which huddling in altricial infants influences individual heat production and loss, while providing public warmth. Although considered as a textbook example, it is surprising to note that physiological mechanisms underlying huddling are still not fully characterised. METHODOLOGY/PRINCIPAL FINDINGS The brown adipose tissue (BAT) contribution to energy output was assessed as a function of the ability of rabbit (Oryctolagus cuniculus) pups to huddle (placed in groups of 6 and 2, or isolated) and of their thermoregulatory capacities (non-insulated before 5 days old and insulated at ca. 10 days old). BAT contribution of pups exposed to cold was examined by combining techniques of infrared thermography (surface temperature), indirect calorimetry (total energy expenditure, TEE) and telemetry (body temperature). Through local heating, the huddle provided each pup whatever their age with an ambient "public warmth" in the cold, which particularly benefited non-insulated pups. Huddling allowed pups facing a progressive cold challenge to buffer the decreasing ambient temperature by delaying the activation of their thermogenic response, especially when fur-insulated. In this way, huddling permitted pups to effectively shift from a non-insulated to a pseudo-insulated thermal state while continuously allocating energy to growth. The high correlation between TEE and the difference in surface temperatures between BAT and back areas of the body reveals that energy loss for non-shivering thermogenesis is the major factor constraining the amount of energy allocated to growth in non-insulated altricial pups. CONCLUSIONS/SIGNIFICANCE By providing public warmth with minimal individual costs at a stage of life when pups are the most vulnerable, huddling buffers cold challenges and ensures a constant allocation of energy to growth by reducing BAT activation.
Collapse
|
14
|
Abstract
Although a few pelagic species exhibit regional endothermy, most fish are regarded as ectotherms. However, we document significant regional endothermy in a benthic reef fish. Individual steephead parrotfish, Chlorurus microrhinos (Labridae, formerly Scaridae) were tagged and their internal temperatures were monitored for a 24 h period using active acoustic telemetry. At night, on the reef, C. microrhinos were found to maintain a consistent average peritoneal cavity temperature 0.16 ± 0.005 °C (SE) warmer than ambient. Diurnal internal temperatures were highly variable for individuals monitored on the reef, while in tank-based trials, peritoneal cavity temperatures tracked environmental temperatures. The mechanisms responsible for a departure of the peritoneal cavity temperature from environmental temperature occurred in C. microrhinos are not yet understood. However, the diet and behavior of the species suggests that heat in the peritoneal cavity may result primarily from endogenous thermogenesis coupled with physiological heat retention mechanisms. The presence of limited endothermy in C. microrhinos indicates that a degree of uncertainty may exist in the manner that reef fish respond to their thermal environment. At the very least, they do not always appear to respond to environmental temperatures as neutral thermal vessels and do display limited, but significant, visceral warming.
Collapse
Affiliation(s)
- Justin Q Welsh
- Australian Research Council Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville, Australia.
| | | |
Collapse
|
15
|
Klingenspor M, Herzig S, Pfeifer A. Brown fat develops a brite future. Obes Facts 2012; 5:890-6. [PMID: 23296106 DOI: 10.1159/000346337] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 12/10/2012] [Indexed: 01/02/2023] Open
|
16
|
Yang DB, Xu YC, Wang DH. Partial removal of brown adipose tissue enhances humoral immunity in warm-acclimated Mongolian gerbils (Meriones unguiculatus). Gen Comp Endocrinol 2012; 175:144-52. [PMID: 22080042 DOI: 10.1016/j.ygcen.2011.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 10/21/2011] [Accepted: 10/25/2011] [Indexed: 11/28/2022]
Abstract
Temperate rodent species experience marked seasonal fluctuations in environmental temperatures. High thermoregulatory demands during winter usually weaken immune function. Brown adipose tissue (BAT) plays a crucial role in adaptive thermoregulatory process. Thus, we proposed the hypothesis that BAT might participate in the regulation of seasonal changes in immune function. The present study examined the trade-off between thermoregulation and immune function and the potential role of BAT in regulating seasonal changes in immune function in Mongolian gerbils. Specifically, surgical removal of interscapular BAT (34% of total BAT) was performed in male gerbils, and subsequently acclimated to either warm (23 ± 1 °C) or cold (4 ± 1 °C) conditions. Gerbils were then challenged with innocuous antigens and the immune responses were measured. Resting metabolic rate (RMR) and nonshivering thermogenesis (NST) were increased under cold conditions. However, the cost of thermoregulation during cold acclimation did not suppress T-cell mediated immunity and humoral immunity or decrease spleen mass, thymus mass and white blood cells. Partial removal of BAT significantly enhanced humoral immunity in warm-acclimated, but not in cold-acclimated gerbils. T-cell mediated immunity, white blood cells and immune organs were not affected by BAT removal under both warm and cold conditions. Collectively, our results imply that BAT has a suppressive effect on humoral immunity in warm-acclimated gerbils and differential effects of BAT on humoral immunity under different temperatures (e.g., summer and winter) might be benefit to their survival.
Collapse
Affiliation(s)
- Deng-Bao Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | | | | |
Collapse
|
17
|
|
18
|
Jones CT, Rolph TP. Metabolic events associated with the preparation of the fetus for independent life. CIBA FOUNDATION SYMPOSIUM 2008; 86:214-33. [PMID: 6802587 DOI: 10.1002/9780470720684.ch10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The metabolic changes late in fetal development that are essential for neonatal survival are discussed. In many species gluconeogenesis develops before birth but provides substrate for intracellular biosynthesis and not for glucose production because of low activities of glucose 6-phosphate translocase. At the time of glycogen deposition in species with a relatively mature brain at birth the translocase develops and glucagon and adrenaline can stimulate glucose production and synthesis to elevate blood glucose concentrations both pre- and postnatally. The other metabolic fuel accumulated before birth, fat, can also be mobilized prenatally and in fetuses that are relatively mature at birth it may be used as an alternative fuel. The fetal rat brain can oxidize fatty acids and the brain of fetuses such as that of the guinea-pig and man can oxidize ketone bodies before birth. The timing and degree of oxidation of ketone bodies relates to the timing of myelination and protects the brain against hypoglycaemia. These late changes in development are associated with a sharp increase in plasma cortisol and adrenaline concentrations and a high fetal insulin concentration.
Collapse
|
19
|
Gilbert C, Blanc S, Giroud S, Trabalon M, Le Maho Y, Perret M, Ancel A. Role of huddling on the energetic of growth in a newborn altricial mammal. Am J Physiol Regul Integr Comp Physiol 2007; 293:R867-76. [PMID: 17459914 DOI: 10.1152/ajpregu.00081.2007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Huddling is considered as a social strategy to reduce thermal stress and promote growth in newborn altricial mammals. So far, the role of huddling on the allocation of saved energy has not been quantified nor have the related impacts on body temperature rhythms. To determine the energy partitioning of rabbit pups either raised alone or in groups of eight, four, or two individuals, when thermoregulatory inefficient (TI) and efficient (TE), we first investigated their total energy expenditure and body composition. We then monitored body temperature and activity rhythms to test whether huddling may impact these rhythms, centered on the suckling event. Pups in a group of eight utilized 40% less energy for thermogenesis when TI than did pups alone and 32% less energy when TE. Pups in groups of eight and four had significantly lower thermoregulatory costs in the TI period, whereas pups in groups of two, four, and eight had lower costs during the TE period. Huddling pups could therefore channel the energy saved into processes of growth and accrued more fat mass (on average 4.5 +/- 1.4 g) than isolated pups, which lost 0.7 g of fat. Pups in groups of four and eight had a body temperature significantly higher by 0.8 degrees C than pups in groups of two and one when TI, whereas no more differences were noted when the TE period was reached. Moreover, pups alone showed an endogenous circadian body temperature rhythm that differed when compared with that of huddling pups, with no rise before suckling. Thus huddling enables pups to invest the saved energy into growth and to regulate their body temperature to be more competitive during nursing, particularly at the early time when they are TI.
Collapse
Affiliation(s)
- Caroline Gilbert
- 1Institut Pluridisciplinaire Hubert Curien (IPHC)-Département Ecologie, Physiologie et Ethologie (DEPE), UMR 7178, Université Louis Pasteur (ULP), Centre National de la Recherche Scientifique (CNRS), Strasbourg, France.
| | | | | | | | | | | | | |
Collapse
|
20
|
Kim S, Krynyckyi BR, Machac J, Kim CK. Concomitant Paravertebral FDG Uptake Helps Differentiate Supraclavicular and Suprarenal Brown Fat Uptake From Malignant Uptake When CT Coregistration Is Not Available. Clin Nucl Med 2006; 31:127-30. [PMID: 16495728 DOI: 10.1097/01.rlu.0000200601.29042.ce] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Fluorine-18 fluorodeoxyglucose (F-18 FDG) uptake in brown adipose tissue (BAT) in the supraclavicular, superior mediastinal, paravertebral, and suprarenal/perinephric regions has been recognized. Of these 4 areas, uptake in the supraclavicular, mediastinal, and suprarenal areas may be difficult to differentiate from malignancy for those who interpret PET images only without CT coregistration or fusion. We assessed the prevalence and concomitance of F-18 FDG uptake in these 4 BAT regions. METHODS A total of 1495 F-18-FDG PET studies were reviewed. Distinct patterns compatible with BAT uptake in the 4 regions were graded and correlated with each other. RESULTS Of the 1495 studies, supraclavicular uptake was seen in 40 (2.7%), paravertebral uptake in 29 (1.9%), mediastinal uptake in 23(1.5%), and suprarenal uptake in 11 (0.7%). Of the 40 studies showing supraclavicular uptake, paravertebral uptake was also seen in 27 (68%), mediastinal uptake in 23 (58%), and suprarenal uptake in 11 (28%). Alternatively, of the 29 studies showing paravertebral uptake, all but 2 studies (93%) also had concomitant supraclavicular uptake. No studies showed isolated mediastinal or suprarenal uptake. All studies with mediastinal uptake also had supraclavicular uptake, and all studies with suprarenal uptake also had paravertebral uptake. CONCLUSIONS Virtually all of mediastinal and suprarenal BAT uptake was associated with supraclavicular and paravertebral uptake, respectively. Nearly all paravertebral uptake coexisted with supraclavicular uptake. Even when CT coregistration is not available, concomitant paravertebral uptake can help differentiate suprarenal uptake and somewhat less typical supraclavicular BAT uptake from malignant uptake, and concomitant supraclavicular uptake can help differentiate mediastinal uptake from malignant uptake.
Collapse
Affiliation(s)
- SunHee Kim
- Division of Nuclear Medicine, Department of Radiology, Mount Sinai School of Medicine, New York, NY, USA
| | | | | | | |
Collapse
|
21
|
Bautista A, Drummond H, Martínez-Gómez M, Hudson R. Thermal benefit of sibling presence in the newborn rabbit. Dev Psychobiol 2003; 43:208-15. [PMID: 14558043 DOI: 10.1002/dev.10134] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Newborn rabbits compete vigorously for the mother's milk, and survivors benefit from littermate deaths. Here we report that rabbit pups also may benefit from littermate presence in terms of increased thermal efficiency. Pups nursed normally once a day by their mother but otherwise raised alone had a lower probability of survival, lower body temperature, and lower efficiency of converting milk into body mass than their siblings raised with littermates. The contribution of a more favorable thermal environment to the better growth and survival of group-raised pups was supported by the finding that single pups raised at higher ambient temperatures grew more rapidly than single pups raised at lower temperatures. These effects were most clearly seen across Days 2 to 5, after which time differences between treatment groups were no longer significant. Thus, the results of this study suggest that the benefits as well as costs of having siblings must be weighed against each other when considering the manner in which sibling presence influences individual development and survival.
Collapse
Affiliation(s)
- A Bautista
- Centro de Investigaciones Fisiológicas, Universidad Autónoma de Tlaxcala, Tlaxcala, México.
| | | | | | | |
Collapse
|
22
|
Pacheco-Cobos L, Rosetti M, Distel H, Hudson R. To stay or not to stay: the contribution of tactile and thermal cues to coming to rest in newborn rabbits. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2003; 189:383-9. [PMID: 12720035 DOI: 10.1007/s00359-003-0413-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2002] [Revised: 03/10/2003] [Accepted: 03/11/2003] [Indexed: 10/25/2022]
Abstract
Newborn rabbits, like other altricial mammals, demonstrate thermotaxis and when placed on a thermal gradient locate and come to rest at physiologically appropriate temperatures. Little is known, however, about the sensory-motor components contributing to the in energetic terms important decision of the young to cease locomotion and come to rest. We investigated the behavior of newborn rabbits on two thermal gradients; linear in which pups could use tactile cues from the arena wall, and concentric in which pups were unable to use such cues. On both gradients pups located the warm, thermal-neutral area within the 200-s test time, thereby demonstrating their ability to orient appropriately using thermal cues alone. Unexpectedly, however, pups on the concentric gradient failed, or took significantly longer, to come to rest than pups on the linear gradient. Since the speed of locomotion of pups on the linear gradient was significantly slowed when they were in contact with the arena wall, and in most cases they came to rest in contact with it, we suggest that not only thermal but also tactile cues may be important in bringing young mammals to rest in a thermally appropriate environment.
Collapse
Affiliation(s)
- L Pacheco-Cobos
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, 04510 México D.F., Mexico
| | | | | | | |
Collapse
|
23
|
Abstract
Three main concerns underlie this review: 1) The need to draw together the widely dispersed information available on the circadian biology of the rabbit. Although the rabbit is a classic laboratory mammal, this extensive body of information is often overlooked by chronobiologists, and despite several advantages of this species. In terms of its general biology the rabbit is the best studied laboratory mammal in the wild, it demonstrates a wide variety of robust circadian functions, and being a lagomorph, it provides a useful comparison with more commonly studied rodent species. 2) The need to more fully exploit a developmental approach to understanding circadian function, and the particular suitability of the rabbit for this. Female rabbits only visit their altricial young for a few minutes once every 24 h to nurse, and survival of the young depends on the tight circadian-controlled synchronization in behavior and physiology of the two parties. Patterns of circadian rhythmicity in neonatal pups associated with nursing do not form a smooth continuum into weaning and adult life, and may reflect the action of separate mechanisms operating in their own right. 3) Using information from the first two points, to emphasize the diversity and complexity of circadian rhythms underlying behavioral and physiological functions in adult and developing mammals. Information accruing on circadian functions in the rabbit makes it increasingly difficult to account for these in terms of one or two regulatory mechanisms or "oscillators." Thus, it is argued that in addition to the reductionist, molecular approaches currently dominating much of chronobiology, the study of circadian systems as emergent characteristics of whole organisms operating in complex environments merits special attention.
Collapse
Affiliation(s)
- B Jilge
- Laboratory Animal Research Unit, University of Ulm, Germany.
| | | |
Collapse
|
24
|
|
25
|
Abstract
The behavioral and physiological thermoregulatory capabilities of newborn and infant mammals have been studied for over half a century. Psychobiologists have noted that the infants of altricial species (e.g., rats) have physical and physiological limitations such that heat loss overwhelms heat production, thus forcing a reliance on behavioral thermoregulation for the maintenance of body temperature. Recent evidence, however, suggests that a modification of this view is justified. Specifically, throughout a range of moderately cold air temperatures, nonshivering thermogenesis by brown adipose tissue contributes significantly to the infant rat's behavioral and physiological adaptations to cold challenge. Given the prominent use of altricial species for the study of infant behavior, increased understanding of the infant's physiological responses to cold and the effect of thermal factors on behavior is warranted.
Collapse
Affiliation(s)
- M S Blumberg
- Department of Psychology, University of Iowa, Iowa City 52242, USA
| | | |
Collapse
|
26
|
Sokoloff G, Kirby RF, Blumberg MS. Further evidence that BAT thermogenesis modulates cardiac rate in infant rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:R1712-7. [PMID: 9841546 DOI: 10.1152/ajpregu.1998.274.6.r1712] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous research in infant rats suggested that brown adipose tissue (BAT), by providing warm blood to the heart during moderate cold exposure, protects cardiac rate. This protective role for BAT thermogenesis was examined further in the present study. In experiment 1, 1-wk-old rats in a warm environment were pretreated with saline or chlorisondamine (a ganglionic blocker), and then BAT thermogenesis was stimulated by injection with the beta3-agonist CL-316243. In experiment 2, pups were pretreated with chlorisondamine and injected with CL-316243, and after BAT thermogenesis was stimulated the interscapular region of the pups was cooled externally with a thermode. In both experiments, cardiac rate, oxygen consumption, and physiological temperatures were monitored. Activation of BAT thermogenesis substantially increased cardiac rate in saline- and chlorisondamine-treated pups, and focal cooling of the interscapular region was sufficient to lower cardiac rate. The results of these studies support the hypothesis that BAT thermogenesis contributes directly to the modulation of cardiac rate.
Collapse
Affiliation(s)
- G Sokoloff
- Department of Psychology, University of Iowa, Iowa City, Iowa 52242, USA
| | | | | |
Collapse
|
27
|
Brzezińska-Slebodzińska E, Slebodziński AB, Styczyńska E. Stimulatory effect of melatonin on the 5'-monodeiodinase activity in the liver, kidney, and brown adipose tissue during the early neonatal period of the rabbit. J Pineal Res 1998; 24:137-41. [PMID: 9551849 DOI: 10.1111/j.1600-079x.1998.tb00525.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The response of type I 5'-monodeiodinase activity (5'-MD) to a s.c. injection or oral administration of melatonin was studied in 3-, 5-, and 7-day-old rabbits. Melatonin-treated animals showed higher activity of the type I 5'-MD in the liver and kidney and of type II 5'-MD in brown adipose tissue (BAT). This respond to melatonin treatment was age dependent. The stimulatory effect of melatonin on renal 5'-MD activity was observed only in 3- and 5-day-old rabbits and in the liver and BAT during the first week of life. Oral melatonin administration tended to exert a more marked effect on enzyme activity than s.c. injection of the hormone. Changes in 5'-MD activities were accompanied by an increase in serum iodothyronine (T4, T3, and rT3) concentrations. The T3 and rT3 increases may result from the deiodinating processes by the type I 5'-MD and 5-MD, respectively, whereas the rise in the serum T4 was probably due to the stimulatory effect of melatonin on the secretory activity of the thyroid gland itself. These results are the first description of the effects evoked by melatonin treatment during the early neonatal period in newborns of the altricial type.
Collapse
Affiliation(s)
- E Brzezińska-Slebodzińska
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Department of Developmental and Experimental Endocrinology, Poznań, Poland
| | | | | |
Collapse
|
28
|
Sjörs G, Hammarlund K, Kjartansson S, Riesenfeld T, Sedin G. Respiratory water loss and oxygen consumption in full-term infants exposed to cold air on the first day after birth. Acta Paediatr 1994; 83:802-7. [PMID: 7981554 DOI: 10.1111/j.1651-2227.1994.tb13147.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Respiratory water loss, oxygen consumption, carbon dioxide production and skin blood flow were measured continuously in nine full-term infants on the first day after birth. After at least 18 min of measurements with the infant asleep in an incubator, with an air temperature of 33 degrees C and a relative humidity of 50%, the temperature of the incubator air was lowered to less than 27.5 degrees C. This resulted in a significant decrease in skin temperature and peripheral skin blood flow, while the infant's core temperature remained unchanged. At the same time, mean respiratory water loss increased from 3.7 to 6.1 mg/kg.min, which can be explained partially by the decrease in ambient humidity that accompanied the decrease in air temperature. In addition, mean oxygen consumption increased from 5.3 to 7.9 ml/kg.min and mean carbon dioxide production increased from 3.8 to 5.9 ml/kg.min. There was no concomitant increase in motor activity. Thus, when the newborn infants were exposed to cool air, they reacted with an increase in respiratory water loss, oxygen consumption and carbon dioxide production before their core temperature was affected and without increasing their motor activity.
Collapse
Affiliation(s)
- G Sjörs
- Department of Paediatrics, University Hospital, Uppsala, Sweden
| | | | | | | | | |
Collapse
|
29
|
Abstract
The present review distinguishes pathogenic, neurogenic, and psychogenic fever, but focuses largely on pathogenic fever, the hallmark of infectious disease. The data presented show that a complex cascade of events underlies pathogenic fever, which in broad outline - and with frank disregard of contradictory data - can be described as follows. An invading microorganism releases endotoxin that stimulates macrophages to synthesize a variety of pyrogenic compounds called cytokines. Carried in blood, these cytokines reach the perivascular spaces of the organum vasculosum laminae terminalis (OVLT) and other regions near the brain where they promote the synthesis and release of prostaglandin (PGE2). This prostaglandin then penetrates the blood-brain barrier to evoke the autonomic and behavioral responses characteristic of fever. But then once expressed, fever does not continue unchecked; endogenous antipyretics likely act on the septum to limit the rise in body temperature. The present review also examines fever-resistance in neonates, the blunting of fever in the aged, and the behaviorally induced rise in body temperature following infection in ectotherms. And finally it takes up the question of whether fever enhances immune responsiveness, and through such enhancement contributes to host survival.
Collapse
Affiliation(s)
- H Moltz
- University of Chicago, IL 60637
| |
Collapse
|
30
|
Brzezińska-Ślebodzińska E, Ślebodziński A. Cold induced changes of thyroxine 5′- and 5-monodeiodinase activity in brown adipose tissue of neonatal rabbits. Implications for thermogenesis. J Therm Biol 1993. [DOI: 10.1016/0306-4565(93)90002-b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
31
|
Noronha M, Raasmaja A, Moolten N, Larsen PR. Triiodothyronine causes rapid reversal of alpha 1/cyclic adenosine monophosphate synergism on brown adipocyte respiration and type II deiodinase activity. Metabolism 1991; 40:1327-32. [PMID: 1683679 DOI: 10.1016/0026-0495(91)90038-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Previous studies have shown that thyroid status affects the response of brown adipose tissue (BAT) to the sympathetic nervous system. For example, hypothyroidism is associated with the development of a marked synergism between alpha 1- and beta-adrenergic pathways to stimulate type II iodothyronine 5'-deiodinase activity. Hypothyroidism also attenuates the respiratory response (thermogenesis) of isolated brown adipocytes to norepinephrine. To explore the interactions of the sympathetic nervous system and thyroid status in these cells, we compared the thermogenic and 5'-deiodinase responses to adrenergic agonists in isolated brown adipocytes from hypothyroid rats during treatment with 3,5,3'-triiodothyronine (T3). The fivefold synergism of alpha 1- and beta-adrenergic catecholamines to increase the deiodinase activity was progressively reduced, reaching a control euthyroid value of unity after 5 days of T3 treatment. Hypothyroidism reduced both the O2max (twofold to threefold) and increased the concentration of agonist required for 50% stimulation (10-fold) for both norepinephrine and forskolin. In hypothyroid cells, there was a twofold synergism between the alpha 1-agonist cirazoline and forskolin to increase respiration, which was blocked by prazosin and reproduced by the calcium ionophore, A23187. This synergistic effect of the alpha 1-agonist was lost within 2 days of T3 administration. These studies identify a second Ca(2+)-dependent intra-adrenergic synergism, which functions to ameliorate the reduced cyclic adenosine monophosphate (cAMP) responsiveness of the hypothyroid brown adipocyte.
Collapse
Affiliation(s)
- M Noronha
- Howard Hughes Medical Institute, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115
| | | | | | | |
Collapse
|
32
|
Neufeld ND, Corbo L, Stoddard A, Klein AH, Tadokoro N. Oxygen consumption and guanosine diphosphate binding by fetal brown adipose tissue in diabetic pregnancy. Metabolism 1989; 38:831-6. [PMID: 2549331 DOI: 10.1016/0026-0495(89)90228-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Oxygen consumption and 3H-guanosine diphosphate (GDP) binding were determined in brown adipocytes and mitochondria from 28-day gestation fetuses of alloxan-diabetic rabbit does and saline-injected controls. Maternal diabetes was classified as severe or mild determined by whether maternal blood glucose values were greater or less than 200 mg/dL, respectively, at death. Basal oxygen consumption and adipocyte diameters did not vary among groups. A significant reduction in maximal norepinephrine (NE) stimulated O2 consumption by fetal brown adipose tissue (BAT) cells was seen in offspring of severely diabetic pregnancies when compared with control values (248 +/- 53 +/- v482 +/- 32 microL O2/10(6) cells/h; P less than .005). In contrast, a significant increase in maximal NE-stimulated O2 consumption by fetal BAT cells occurred in offspring of mild diabetic pregnancies (807 +/- 60, P less than .001 v controls). A highly significant inverse correlation between serum glucose levels and maximal O2 consumption by fetal BAT was observed in fetuses from mild and severe diabetic pregnancies (r = -.98, P less than .005), and there was no correlation between these two parameters in offspring of normal pregnancies. A significant inverse correlation was observed between maximal O2 consumption by fetal BAT cells and serum insulin levels in offspring of both control and diabetic pregnancy (r = -.74; P less than .02). Tissue cytochrome oxidase activity was lower in offspring of severely affected diabetic does, indicating a reduction in BAT mitochondrial content compared with controls. BAT mitochondria from fetuses of severely diabetic does exhibited reduced 3H-GDP capacity, which was 2.5-fold lower than controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- N D Neufeld
- Division of Endocrinology, Ahmanson Pediatric Center, Cedar-Sinai Medical Center, UCLA School of Medicine 90048
| | | | | | | | | |
Collapse
|
33
|
|
34
|
Sullivan RM, Wilson DA, Leon M. Physical stimulation reduces the brain temperature of infant rats. Dev Psychobiol 1988; 21:237-50. [PMID: 3371556 PMCID: PMC1892163 DOI: 10.1002/dev.420210305] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Previous work indicated that physical stimulation, such as that which mimics the stimulation pups receive from the dam, reduces pup body temperature. The present paper reports that the body and brain temperature of 5-day-old pups covaried under steady-state thermal conditions, cold exposure, and warmth exposure (Expt. 1) suggesting that body thermoregulatory mechanisms may also regulate brain temperature. Indeed, physically stimulating pups decreased brain temperature in the neocortex (Expt. 2) and the olfactory bulb (Expt. 3). The mechanism for this brain temperature decrease appears to be an increase in ventilatory heat exchange, the same mechanism responsible for the decrease in body temperature. Pups increased respiration during stimulation, thereby increasing air flow to the lungs where convective and evaporative heat exchange occurred. Indeed, stimulating pups in a high-humidity environment blocked the decrease in brain temperature (Expt. 4). The ability of physical stimulation to decrease brain temperature appears to be limited to neonatal pups, as 10-, 15-, and 20-day-old pups did not exhibit a brain temperature decrease in response to stimulation (Expt. 5).
Collapse
Affiliation(s)
- R M Sullivan
- Department of Psychobiology, University of California, Irvine 92717
| | | | | |
Collapse
|
35
|
Sullivan RM, Shokrai N, Leon M. Physical stimulation reduces the body temperature of infant rats. Dev Psychobiol 1988; 21:225-35. [PMID: 3371555 PMCID: PMC1892173 DOI: 10.1002/dev.420210304] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Physical stimulation of rat pups, of the type normally received from the mother, has been shown to regulate several behavioral and physiological systems in the young. The present paper describes a possible role of physical stimulation in an additional physiological system; the thermoregulatory system. Within a thermoneutral environment, physical stimulation produces a decrease in rectal temperature (Expt. 1). Even in an environment of increasing temperature, similar to that pups experience when in contact with the dam, physical stimulation attenuates an increase in rectal temperature (Expt. 2). The physiological mechanism of heat loss appears to involve ventilatory heat exchange resulting in convective and evaporative heat loss (Expts. 3, 4). Furthermore, physical stimulation continues to produce a decrease in rectal temperature throughout the preweanling period (Expt. 5). These results suggest that pups may not always have to resort to behavioral thermoregulatory mechanisms which require them to separate themselves from their mother. Rather, pups may be cooled, or at least a heat gain attenuated, by physical stimulation from the dam while maintaining contact with her.
Collapse
Affiliation(s)
- R M Sullivan
- Department of Psychobiology, University of California, Irvine 92717
| | | | | |
Collapse
|
36
|
Schröder HJ, Hüneke B, Klug A, Stegner H, Carstensen M, Leichtweiss HP. Fetal sheep temperatures in utero during cooling and application of triiodothyronine, norepinephrine, propranolol and suxamethonium. Pflugers Arch 1987; 410:376-84. [PMID: 3124078 DOI: 10.1007/bf00586514] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Fetal sheep (n = 13) were chronically instrumented to measure temperatures in the maternal femoral artery (MAT), the amniotic fluid (AFT), the fetal brown adipose tissue (BFT) and the fetal arterial blood (DAT). Cooling loops were inserted into the amniotic cavity. In 4 fetuses osmotic minipumps delivering triiodothyronine (T3) were implanted subcutaneously. One to seven days after surgery the following results were obtained: 1) During control DAT was 0.59 +/- 0.2 degrees C (SD), BFT 0.60 +/- 0.24 degrees C and AFT 0.38 +/- 0.31 degrees C higher than MAT. T3 levels in treated fetuses were 3.4 +/- 1.5 micrograms/l. 2) Infusion of norepinephrine (NE) (5.2 +/- 0.9 micrograms/min per kg fetal body weight) with phentolamine (26.1 +/- 4.3 micrograms/min per kg) into a fetal vein did not change temperatures. 3) During cooling (-53 +/- 15 W) MAT decreased 0.45 +/- 0.3 degrees C, DAT 1.9 +/- 0.39 degrees C, BFT 1.61 +/- 0.52 degrees C and AFT 4.2 +/- 1.8 degrees C. 4) The amniotic fluid was cooled until steady state temperatures were achieved. Then propranolol (26.1 +/- 4.3 micrograms/min per kg) or suxamethonium (3 +/- 1 mg/kg) were introduced into the fetal vein. No consistent and significant changes of temperatures could be detected. It is concluded that 1) lowering the fetal core temperature by 1.6 - 1.9 degrees C and its ambient temperature (AFT) by 4.2 degrees C does not induce shivering or non-shivering thermogenesis suppressible by pharmacologic agents, 2) thermogenesis in fetal brown adipose tissue cannot be induced by NE (with or without supplemention of T3).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- H J Schröder
- Universitäts-Frauenklinik, Abt. experimentelle Medizin, Hamburg, Federal Republic of Germany
| | | | | | | | | | | |
Collapse
|
37
|
Franzini C, Cianci T, Lenzi P, Libert JP, Horne JA, Parmeggiani PL. Influence of brown adipose tissue on deep cervical temperature during sleep in the young rabbit. EXPERIENTIA 1986; 42:604-6. [PMID: 3720911 DOI: 10.1007/bf01955554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In young rabbits the slope of the temperature in the deep cervical region close to brown adipose tissue increased during desynchronized sleep at low ambient temperature. No increase occurred at neutral ambient temperature. In control rabbits (after disappearance of brown adipose tissue), the slope of deep cervical temperature did not increase during desynchronized sleep at low or neutral ambient temperatures.
Collapse
|
38
|
Leon M. Development of Thermoregulation. DEVELOPMENTAL PSYCHOBIOLOGY AND DEVELOPMENTAL NEUROBIOLOGY 1986. [DOI: 10.1007/978-1-4613-2113-2_8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
39
|
Heldmaier G, Buchberger A. Sources of heat during nonshivering thermogenesis in Djungarian hamsters: a dominant role of brown adipose tissue during cold adaptation. J Comp Physiol B 1985; 156:237-45. [PMID: 3836234 DOI: 10.1007/bf00695778] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
To assess the thermogenic importance of BAT in Djungarian hamsters we removed about 40% of their BAT and compared their thermogenic abilities before and after the operation. BAT was weighed and assayed for its respiratory properties (Cox, mitochondria). Following removal of BAT we observed considerable reductions of NST. The comparison of NST with BAT weight and with respiratory properties of BAT following partial removal of BAT revealed that at least three different pathways for heat production were involved in NST. In cold-adapted hamsters (values for warm-adapted hamsters in parentheses) we estimated that 66.2% (37.0%) of all NST was produced by mitochondrial respiration in BAT; 16.3% (38.4%) was produced in other organ sites but required the presence of BAT, i.e. there was a mediatory action of BAT on thermogenesis in other organ sites. A further 11.5% (23%) of NST occurred outside of and independent of BAT. Mitochondrial respiration in BAT was the only compartment of NST which increased its contribution during cold adaptation (238 mW to 1,062 mW), whereas the other sources of heat remained largely unchanged.
Collapse
|
40
|
Adaptive changes in skeletal muscle mitochondria of the guinea-pig during acclimation to cold. ACTA ACUST UNITED AC 1983. [DOI: 10.1007/bf00455187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
41
|
Hervey GR, Tobin G. The part played by variation of energy expenditure in the regulation of energy balance. Proc Nutr Soc 1982; 41:137-53. [PMID: 6810362 DOI: 10.1079/pns19820024] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
42
|
Klein AH, Jenkins JJ, Reviczky A, Fisher DA. Thyroid hormone-sensitive brown adipose tissue respiration in the newborn rabbit. THE AMERICAN JOURNAL OF PHYSIOLOGY 1981; 241:E449-53. [PMID: 6275713 DOI: 10.1152/ajpendo.1981.241.6.e449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effects of thyroid hormone treatment on brown adipose tissue (BAT) and liver metabolism were assessed by measuring oxygen consumption, sodium-potassium adenosine triphosphatase (Na-K-ATPase), and mitochondrial alpha-glycerophosphate dehydrogenase (alpha-GPD) activities in tissues from triiodothyronine- (T3) and vehicle-injected (for 3 days) newborn and adult rabbits. In the newborns, basal BAT cellular respiration was increased [mean (%/- SE) = 119 +/- 18 vs. 65 +/- 4 microliter O2/10(6) cells-1 . h in controls (P less than 0.005)], whereas hepatic respiration was unchanged. Ouabain had no effect on basal BAT cellular respiration, but suppressed hepatic respiration by 30% in both newborn groups. T3 treatment had no effect on NE- (10(-6) M) stimulated BAT respiration, whereas adult hepatic respiration was increased almost twofold. alpha-GPD activities were increased in both newborn BAT and adult liver but not in newborn liver. Na-K-ATPase activity was significantly increased only in newborn liver. In conclusion, 1) both BAT and liver are thyroid-hormone sensitive in the newborn rabbit, but the responses to T3 treatment are different in the two tissues; 2) the failure to stimulate both hepatic alpha-GPD and respiration in the newborn appears to be a developmental phenomenon characteristic of the rabbit; 3) thyroid hormones have little effect on sodium transport-dependent respiration in either BAT of liver in the newborn rabbit.
Collapse
|
43
|
Abstract
Basal and norepinephrine (NE) stimulated oxygen consumption was measured in BAT cells isolated from fetal and newborn rabbits at 24, 28, and 31 days gestation, and 3 and 10 days postnatal age. Maximum catecholamine stimulated respiration was measured at a final NE concentration of 10(-6) M. Cell diameter, calculated cell volume and mitochondrial alpha glycerophosphate dehydrogenase (alpha GPD) were also determined at each age. Basal respiration increased continuously during fetal and neonatal life from a mean (+/- SEM) of 12.2 +/- 0.4 mul O2/10(6) cells . hr at 24 days gestation to a mean of 70.5 +/- 4.2 mul O2/10(6) cells . hr at 24 days gestation to 670.5 +/- 60.4 mul O2/10(6) cells . hr at 31 days. A further increase of 30% measured at 10 days of age was also observed. BAT mitochondrial alpha GPD activity was several fold greater than that measured in liver. Both cell size and enzyme activity increased in parallel to increasing respiratory response to NE. We conclude from this data that the maturation of catecholamine stimulated BAT thermogenesis occurs primarily in the fetus prior to delivery. This increase is associated with both an increase in mitochondrial enzyme activity and an increase in cell size.
Collapse
|
44
|
Abstract
1. The occurrence of dietary and cold-induced thermogenesis in young rabbits was unaffected by noradrenaline or propranolol, and it is concluded that the brown adipose tissue, although detectable histologically, is non-functional. 2. Noradrenaline treatment caused an increase in oxygen consumption in albino, but not in hooded rats, suggesting that the former breed may possess brown adipose tissue capable of thermogenesis.
Collapse
|
45
|
|
46
|
Abstract
The Sudden Infant Death Syndrome (SIDS) is the most frequent cause of death in infants aged between one month and one year, yet its cause remains unknown. The present hypothesis is that most infants who die of SIDS have an abnormality of the catecholaminergic system, possible genetically determined, which results in a decreased thermogenic response to cold, owing to a deficiency in noradrenaline (NA), which eventually results in severe hypothermia. A series of complex, but interrelated reactions of the infant to the hypothermia and its consequences leads to death. The final mechanism of regulatory failure involves a deterioration of cardiorespiratory function resulting from hypoxia, metabolic acidosis and hypoglycemia. The etiology of "near miss" for SIDS is also unknown. It is postulated that these infants have a similar but milder deficiency which may be due, in part, to genetic factors. Determinations of central and peripheral catecholamines in "near miss" and normal infants will be performed to test this hypothesis.
Collapse
|
47
|
Barnard T. Brown adipose tissue as an effector of nonshivering thermogenesis. EXPERIENTIA 1977; 33:1124-6. [PMID: 891845 DOI: 10.1007/bf01922278] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
48
|
|
49
|
Rosen RC. Ontogeny of homeothermy in Microtus pennsylvanicus and Octodon degus. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1975; 52:675-9. [PMID: 1195 DOI: 10.1016/s0300-9629(75)80022-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
50
|
Bignall KE, Heggeness FW, Palmer JE. Effect of neonatal decerebration on thermogenesis during starvation and cold exposure in the rat. Exp Neurol 1975; 49:174-88. [PMID: 1183523 DOI: 10.1016/0014-4886(75)90203-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|