1
|
Ferner K, Schultz JA, Zeller U. Comparative anatomy of neonates of the three major mammalian groups (monotremes, marsupials, placentals) and implications for the ancestral mammalian neonate morphotype. J Anat 2017; 231:798-822. [PMID: 28960296 PMCID: PMC5696127 DOI: 10.1111/joa.12689] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2017] [Indexed: 12/16/2022] Open
Abstract
The existing different modes of reproduction in monotremes, marsupials and placentals are the main source for our current understanding of the origin and evolution of the mammalian reproduction. The reproductive strategies and, in particular, the maturity states of the neonates differ remarkably between the three groups. Monotremes, for example, are the only extant mammals that lay eggs and incubate them for the last third of their embryonic development. In contrast, marsupials and placentals are viviparous and rely on intra-uterine development of the neonates via choriovitelline (mainly marsupials) and chorioallantoic (mainly placentals) placentae. The maturity of a newborn is closely linked to the parental care strategy once the neonate is born. The varying developmental degrees of neonates are the main focus of this study. Monotremes and marsupials produce highly altricial and nearly embryonic offspring. Placental mammals always give birth to more developed newborns with the widest range from altricial to precocial. The ability of a newborn to survive and grow in the environment it was born in depends highly on the degree of maturation of vital organs at the time of birth. Here, the anatomy of four neonates of the three major extant mammalian groups is compared. The basis for this study is histological and ultrastructural serial sections of a hatchling of Ornithorhynchus anatinus (Monotremata), and neonates of Monodelphis domestica (Marsupialia), Mesocricetus auratus (altricial Placentalia) and Macroscelides proboscideus (precocial Placentalia). Special attention was given to the developmental stages of the organs skin, lung, liver and kidney, which are considered crucial for the maintenance of vital functions. The state of the organs of newborn monotremes and marsupials are found to be able to support a minimum of vital functions outside the uterus. They are sufficient to survive, but without capacities for additional energetic challenges. The organs of the altricial placental neonate are further developed, able to support the maintenance of vital functions and short-term metabolic increase. The precocial placental newborn shows the most advanced state of organ development, to allow the maintenance of vital functions, stable thermoregulation and high energetic performance. The ancestral condition of a mammalian neonate is interpreted to be similar to the state of organ development found in the newborns of marsupials and monotremes. In comparison, the newborns of altricial and precocial placentals are derived from the ancestral state to a more mature developmental degree associated with advanced organ systems.
Collapse
Affiliation(s)
- Kirsten Ferner
- Leibniz‐Institut für Evolutions‐ und BiodiversitätsforschungMuseum für NaturkundeBerlinGermany
| | - Julia A. Schultz
- Department of Organismal Biology and AnatomyUniversity of ChicagoChicagoILUSA
| | - Ulrich Zeller
- Lebenswissenschaftliche FakultätFG Spezielle ZoologieAlbrecht Daniel Thaer‐Institut für Agrar‐ und GartenbauwissenschaftenHumboldt‐Universität zu BerlinBerlinGermany
| |
Collapse
|
2
|
Maurer SF, Fromme T, Grossman LI, Hüttemann M, Klingenspor M. The brown and brite adipocyte marker Cox7a1 is not required for non-shivering thermogenesis in mice. Sci Rep 2015; 5:17704. [PMID: 26635001 PMCID: PMC4669493 DOI: 10.1038/srep17704] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/03/2015] [Indexed: 12/11/2022] Open
Abstract
The cytochrome c oxidase subunit isoform Cox7a1 is highly abundant in skeletal muscle and heart and influences enzyme activity in these tissues characterised by high oxidative capacity. We identified Cox7a1, well-known as brown adipocyte marker gene, as a cold-responsive protein of brown adipose tissue. We hypothesised a mechanistic relationship between cytochrome c oxidase activity and Cox7a1 protein levels affecting the oxidative capacity of brown adipose tissue and thus non-shivering thermogenesis. We subjected wildtype and Cox7a1 knockout mice to different temperature regimens and tested characteristics of brown adipose tissue activation. Cytochrome c oxidase activity, uncoupling protein 1 expression and maximal norepinephrine-induced heat production were gradually increased during cold-acclimation, but unaffected by Cox7a1 knockout. Moreover, the abundance of uncoupling protein 1 competent brite cells in white adipose tissue was not influenced by presence or absence of Cox7a1. Skin temperature in the interscapular region of neonates was lower in uncoupling protein 1 knockout pups employed as a positive control, but not in Cox7a1 knockout pups. Body mass gain and glucose tolerance did not differ between wildtype and Cox7a1 knockout mice fed with high fat or control diet. We conclude that brown adipose tissue function in mice does not require the presence of Cox7a1.
Collapse
Affiliation(s)
- Stefanie F Maurer
- Chair of Molecular Nutritional Medicine, Technische Universität München, Else Kröner-Fresenius Center for Nutritional Medicine &ZIEL-Institute for Food and Health, 85350 Freising-Weihenstephan, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, Technische Universität München, Else Kröner-Fresenius Center for Nutritional Medicine &ZIEL-Institute for Food and Health, 85350 Freising-Weihenstephan, Germany
| | - Lawrence I Grossman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Martin Klingenspor
- Chair of Molecular Nutritional Medicine, Technische Universität München, Else Kröner-Fresenius Center for Nutritional Medicine &ZIEL-Institute for Food and Health, 85350 Freising-Weihenstephan, Germany
| |
Collapse
|
3
|
Seasonal changes of thermogenic capacity in Melano-bellied oriental voles (Eothenomys melanogaster). ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.chnaes.2010.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
4
|
Szdzuy K, Zeller U. Lung and metabolic development in mammals: contribution to the reconstruction of the marsupial and eutherian morphotype. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2009; 312:555-78. [PMID: 18623108 DOI: 10.1002/jez.b.21228] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Marsupials represent only 6% of all living mammals. Marsupialia and Placentalia are distinguished mainly by their modes of reproduction. In particular, the differences in the stage of development of the neonates may be one explanation for the divergent evolutionary success. In this respect one important question is whether the survivability of the neonate depends on the degree of maturation of the respiratory system relative to the metabolic capacity at the time of birth. Therefore, this review highlights the differences in lung morphology and metabolic development of extant Marsupialia and Placentalia. The Marsupial neonate is born with a low birth weight and is highly immature. The neonatal lung is characterized by large terminal sacs, a poorly developed bronchial system and late formation of alveoli. Marsupialia have a low metabolic rate at birth and attain adult metabolic rate and thermoregulatory capacity late in postnatal development. In contrast, the eutherian neonate is born with a relative high birth weight and is always more mature than marsupial neonates. The neonatal lung has small terminal sacs, the bronchial system is well developed and the formation of alveoli begins few days after birth. Placentalia have a high metabolic rate at birth and attain adult metabolic rate and thermoregulatory capacity early in postnatal development. The differences in the developmental degree of the newborn lung between Marsupialia and Placentalia have consequences for their metabolic and thermoregulatory capacity. These differences could be advantageous for Placentalia in the changing environments in which they evolved.
Collapse
Affiliation(s)
- Kirsten Szdzuy
- Institute of Systematic Zoology, Museum of Natural History, Berlin, Germany.
| | | |
Collapse
|
5
|
Carroll AM, Haines LR, Pearson TW, Fallon PG, Walsh CM, Brennan CM, Breen EP, Porter RK. Identification of a functioning mitochondrial uncoupling protein 1 in thymus. J Biol Chem 2005; 280:15534-43. [PMID: 15695816 DOI: 10.1074/jbc.m413315200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We present evidence that rat and mouse thymi contain mitochondrial uncoupling protein (UCP 1). Reverse transcriptase-PCR detected RNA transcripts for UCP 1 in whole thymus and in thymocytes. Furthermore, using antibodies to UCP 1 the protein was also detected in mitochondria isolated from whole thymus and thymocytes but not in thymus mitochondria from UCP 1 knock-out mice. Evidence for functional UCP 1 in thymus mitochondria was obtained by a comparative analysis with the kinetics of GDP binding in mitochondria from brown adipose tissue. Both tissues showed equivalent B(max) and K(D) values. In addition, a large component of the nonphosphorylating oxygen consumption by thymus mitochondria was inhibited by GDP and subsequently stimulated by addition of nanomolar concentrations of palmitate. UCP 1 was purified from thymus mitochondria by hydroxyapatite chromatography. The isolated protein was identified by peptide mass mapping and tandem mass spectrometry by using MALDI-TOF and LC-MS/MS, respectively. We conclude that the thymus contains a functioning UCP 1 that has the capacity to regulate metabolic flux and production of reactive oxygen-containing molecules in the thymus.
Collapse
Affiliation(s)
- Audrey M Carroll
- Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Oudart H, Calgari C, Andriamampandry M, Le Maho Y, Malan A. Stimulation of brown adipose tissue activity in tumor-bearing rats. Can J Physiol Pharmacol 1995; 73:1625-31. [PMID: 8789417 DOI: 10.1139/y95-724] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Despite anorexia, cancer development is frequently accompanied by an increase of energy expenditure. Considering the pivotal role played by brown adipose tissue (BAT) in the energy metabolism of small mammals, we investigated the functional and compositional modification in BAT of anorexic tumor-bearing (Yoshida sarcoma) and pair-fed control rats. BAT thermogenic activity (assessed by maximal mitochondrial GDP binding) was 1.8-fold greater in tumor-bearing rats than in controls, while the thermogenic capacity (assessed by measurement of uncoupling protein) was unchanged. This suggests that tumor bearing had induced an unmasking of uncoupling protein sites. BAT hypertrophy and hyperplasia, characteristic of full-fledged BAT activation, did not occur. The mitochondrial oxidative capacity of BAT (assessed by cytochrome c oxidase activity) was 1.6-fold lower in tumor-bearing than in control rats. The main compositional modification observed in BAT of tumor-bearing rats was an increase in the saturation of cardiolipin fatty acids. These results suggest that the BAT stimulation induced by tumor bearing after 10 days is almost exclusively functional and that the tissue development is limited, probably by anorexia. However, a suppressive effect of anorexia inhibition by tumor bearing cannot be excluded.
Collapse
Affiliation(s)
- H Oudart
- Centre d'écologie et physiologie énergétiques, associé à l'Université Louis Pasteur, Strasbourg, France
| | | | | | | | | |
Collapse
|
7
|
Huang SG, Klingenberg M. Nature of the masking of nucleotide-binding sites in brown adipose tissue mitochondria. Involvement of endogenous adenosine triphosphate. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 229:718-25. [PMID: 7758468 DOI: 10.1111/j.1432-1033.1995.tb20519.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Binding of the fluorescent nucleotide derivative 2'-O-dansyl GTP and purine nucleotides to brown adipose tissue mitochondria from hamster was studied. 2'-O-Dansyl GTP binds with enhanced fluorescence to the uncoupling protein (UCP) in the mitochondria, similar to the isolated protein. The fluorescence signal showed biphasic fast and slow increases. Treatment of the mitochondria with an anion exchanger (Dowex) increased the total fluorescence but decreased the slower phase. The biphasic fluorescence response was restored by incubation with only 1 microM ATP, indicating that residual bound ATP may be responsible for the observed slow phase. The binding of [14C]GTP and GDP also increased after Dowex treatment. The dissociation of bound [14C]ATP but not of bound [14C]ADP was slow and apparently limited the binding assays. Short incubation (5 min) resulted in a curvature of the Scatchard plot, where the 'high-affinity sites' correspond to the free UCP sites; GDP had apparently higher affinity than GTP. Dowex treatment and incubation for 60 min produced a more linear Scatchard plot. Under such conditions, one measures the maximal UCP-binding sites (1.2 mumol/g protein); GTP exhibited higher affinity (Kd = 0.64 microM) than GDP (Kd = 3.1 microM). Acute cold adaptation (40 min at 4 degrees C) of hamsters caused an increase by over 40% of [14C]GTP binding, as compared to the control warm-(28 degrees C)-adapted animals. Dowex treatment completely abolishes this unmasking/masking effect, where both mitochondria had identical binding capacity and affinity for GTP. The inhibition by purine nucleotides of H+ transport as measured by potassium-acetate-induced mitochondrial swelling was dependent on the incubation time. Diphosphates inhibited faster and triphosphates required longer incubation (10 min) but inhibited more strongly. A linear correlation between the mitochondrial swelling rate and GDP binding was observed for mitochondria with depleted endogenous ATP or with added ATP. These data indicate that residual bound ATP from the tissue is responsible for the masking phenomenon.
Collapse
Affiliation(s)
- S G Huang
- Institute of Physical Biochemistry, University of Munich, Germany
| | | |
Collapse
|
8
|
Chapter 17 The uncoupling protein thermogenin and mitochondrial thermogenesis. MOLECULAR MECHANISMS IN BIOENERGETICS 1992. [DOI: 10.1016/s0167-7306(08)60185-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
9
|
Pazos-Moura CC, Moura EG, Dorris ML, Rehnmark S, Melendez L, Silva JE, Taurog A. Effect of iodine deficiency and cold exposure on thyroxine 5'-deiodinase activity in various rat tissues. THE AMERICAN JOURNAL OF PHYSIOLOGY 1991; 260:E175-82. [PMID: 1996620 DOI: 10.1152/ajpendo.1991.260.2.e175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We measured thyroxine 5'-deiodinase I (T(4)5'D-I) activity in thyroid, liver, and kidney and thyroxine 5'-deiodinase II (T(4)5'D-II) activity in brown adipose tissue (BAT) in rats on a low-iodine diet (LID) to test the possibility that increased deiodinase activity in these tissues might contribute to the maintenance of ther serum 3,5,3'-triiodothyronine (T3) level. Control rats received LID plus KI. Experiments were also performed with LID and LID plus KI rats exposed to cold. T(4)5'D-I activity was greatly increased in the thyroids of LID rats but not in liver or kidney. We consider it likely that increased thyroxine (T4)-to-T3 conversion in the greatly enlarged thyroids of LID rats contributed to the maintenance of serum T3. T(4)5'D-II activity in BAT was markedly increased in LID rats and was further greatly increased on cold exposure. However, we were unable to demonstrate an increase in uncoupling protein mRNA levels in BAT in response to cold in LID rats. We attribute this to the very low serum T4 level, which limits substrate availability. This factor also makes it unlikely that BAT contributes to maintenance of serum T3 in LID rats.
Collapse
Affiliation(s)
- C C Pazos-Moura
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235
| | | | | | | | | | | | | |
Collapse
|
10
|
Klaus S, Casteilla L, Hentz E, Dani C, Ricquier D. The mRNA of protein disulfide isomerase and its homologue the thyroid hormone binding protein is strongly expressed in adipose tissue. Mol Cell Endocrinol 1990; 73:105-10. [PMID: 2269393 DOI: 10.1016/0303-7207(90)90123-p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The thyroid hormone 3,3',5-triiodothyronine (T3) plays an important role in the differentiation of adipocytes, as well as in the thermogenic activity of brown adipose tissue. Recently a T3 binding protein (T3BP), which is associated with plasma membranes, has been isolated and cloned from liver. It proved to be homologous to the multifunctional enzyme protein disulfide isomerase (PDI), which is involved in posttranslational modifications of secretory proteins. In this study we investigated the T3BP/PDI mRNA expression in white and brown adipose tissue of rat and bovine, as well as in several rodent adipose cell lines at various states of differentiation. T3BP/PDI mRNA expression was found in white and brown adipose tissue, as well as in preadipocytes and adipocytes at all states of differentiation. Comparison to other tissues (liver, kidney, heart, brain) revealed that its expression was highest in white fat. No modulation of T3BP/PDI mRNA corresponding to different adaptational or developmental situations could be detected in adipose tissue.
Collapse
Affiliation(s)
- S Klaus
- Centre de Recherche sur la Nutrition (CNRS), Meudon Bellevue, France
| | | | | | | | | |
Collapse
|
11
|
Loncar D, Afzelius BA. Ontogenetical changes in adipose tissue of the cat: convertible adipose tissue. JOURNAL OF ULTRASTRUCTURE AND MOLECULAR STRUCTURE RESEARCH 1989; 102:9-23. [PMID: 2621379 DOI: 10.1016/0889-1605(89)90028-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The ultrastructural characteristics of the inguinal, interscapular, and perirenal adipose tissue in kittens and cats were studied. There were no qualitative differences among adipocytes in the three anatomical areas. The only recorded difference was in the amount of lipids stored in the adipocytes in younger stages. Immediately after birth lipids occupied 25% of the volume in the inguinal area, 15% in interscapular fat tissue, and 10% in perirenal fat tissue. At this stage the adipose tissue morphologically resembled brown adipose tissue (BAT) of rodents. Two weeks after birth, lipids accumulated and adipocytes in the inguinal area became unilocular and appeared similar to white adipose tissue (WAT). A similar transition occurred approx 25 days after birth in interscapular fat and approx 6 weeks after birth in the perirenal area. No morphological signs of any cell degradation or destruction, nor any increased activity of preadipocytes, were seen during this conversion from BAT-like to WAT-like adipose tissue. The conversion of the adipose tissue was correlated with a decrease in vascularization and innervation, a loss of intercellular connections, and a changed mitochondrial population. Mitochondria in multilocular adipocytes resembled those in typical BAT which contain uncoupling protein ("UC-mitochondria"). After conversion to unilocular adipocytes the amount of mitochondria was halved, their cristae even more reduced, and their appearance was of a WAT-type (UCP-lacking mitochondria, which are coupled under physiological conditions; "C-mitochondria"). Since this category of adipose tissue differs from both typical brown and white adipose tissue, the name "convertible adipose tissue" (CAT) is proposed. Apparently adipose tissue from comparatively large mammals is of this convertible type.
Collapse
Affiliation(s)
- D Loncar
- University of Stockholm, Wenner-Gren Institute, Stockholm, Sweden
| | | |
Collapse
|
12
|
Loncar D, Afzelius BA, Cannon B. Epididymal white adipose tissue after cold stress in rats. II. Mitochondrial changes. JOURNAL OF ULTRASTRUCTURE AND MOLECULAR STRUCTURE RESEARCH 1988; 101:199-209. [PMID: 3151905 DOI: 10.1016/0889-1605(88)90010-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We have previously shown that after severe cold stress of rats the epididymal white adipose tissue (WAT) acquires many of the morphological characteristics (innervation, vascularization, appearance of adipocytes) of brown adipose tissue (BAT). In the present study, the mitochondrial characteristics have been analyzed. Mitochondria from the epididymal fat pad of cold-stressed rats became enlarged and had a volume 1.7 times greater than that in the control group (0.5 microns 3 in the experimental versus 0.3 microns 3 in the control group). The mitochondria occupied about 60% of the cytoplasm (14% in the control group), thus approaching the highest value reported for any cell. The straight or slightly wavy cristae completely traversed the width of the mitochondria and occupied an area of 26 microns 2/1 microns 3 of mitochondrion in the experimental adipose tissue (7 microns 2 in the control group) and 15 microns 2/1 microns 3 of cytoplasm (1.4 microns 2 in the control). The mitochondrial matrix became electron lucid and could contain lamellar whorls, as could the surface of the mitochondria. These mitochondria of epididymal WAT resembled, both morphologically and morphometrically, mitochondria in the BAT of cold-exposed rodents. In the epididymal mitochondria, immunoelectron microscopy did not reveal the presence of the BAT-specific uncoupling protein thermogenin, nor could the slot-blot technique detect thermogenin mRNA. We conclude that even under these extreme conditions of cold stress, WAT cannot adopt the thermogenin-dependent thermogenesis of BAT. The dramatic mitochondriogenesis can be interpreted only as being indicative of an extremely high metabolism in the tissue, thus placing unprecedented pressure on the energy turnover capacity of the cell.
Collapse
Affiliation(s)
- D Loncar
- University of Stockholm, Wenner-Gren Institute, Sweden
| | | | | |
Collapse
|
13
|
Giralt M, Martin I, Mampel T, Villarroya F, Iglesias R, Viñas O. Evidence for a differential physiological modulation of brown fat iodothyronine 5'-deiodinase activity in the perinatal period. Biochem Biophys Res Commun 1988; 156:493-9. [PMID: 3178848 DOI: 10.1016/s0006-291x(88)80868-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Brown adipose tissue iodothyronine 5'-deiodinase increases progressively in fetuses from the day 17 of pregnancy on, it reaches peak values on the 20th day of gestation and declines in the last days of fetal life as well as during the first day of life. Birth of premature fetuses causes a sudden drop in the enzyme activity. Postmaturity is associated to a decrease in brown fat 5'-deiodinase similar to that found after birth in fetuses born at term. In the first hours of life brown fat iodothyronine 5'-deiodinase is essentially insensitive to the cold-stimulus. Present data indicates that, differently from adult rats, brown fat iodothyronine 5'-deiodinase activity during the perinatal period is dissociated from the thermogenic activity of the tissue. It is suggested that factors different from the action of the sympathetic nervous system may play a main role in brown fat iodothyronine 5'-deiodinase activity modulation in the fetal and neonatal life.
Collapse
Affiliation(s)
- M Giralt
- Department de Bioquimica i Fisiologia, Universitat de Barcelona, Spain
| | | | | | | | | | | |
Collapse
|
14
|
Nedergaard J, Cannon B. [3H]GDP binding and thermogenin amount in brown adipose tissue mitochondria from cold-exposed rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1985; 248:C365-71. [PMID: 3919594 DOI: 10.1152/ajpcell.1985.248.3.c365] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Brown fat mitochondria were isolated from cold-exposed and control rats, and their content of the brown-fat-specific 32-kDa "uncoupling" protein thermogenin determined both by the traditional [3H]GDP-binding method and by the recently developed enzyme-linked immunosorbent assay (ELISA). In mitochondria isolated from both cold-acclimated (3 wk at 4 degrees C) and cold-exposed rats (24 h), an increase in thermogenin content was observable, both when estimated by the [3H]GDP-binding method and by the ELISA assay, and there was no statistically significant difference in the magnitude of these increases in the two methods. In 1 h cold-exposed rats there was no increase in [3H]GDP binding or in the ELISA reaction. When the amount of thermogenin was plotted against [3H]GDP binding in the different states, a relationship of 75,000 g thermogenin per mole GDP bound was obtained. Based on the resolution of these two methods, and under the three conditions investigated, it was concluded that there was no reason to postulate the existence of a "masked" form of thermogenin or of an "unmasking" process and that thermogenin in the mitochondria, as in the isolated state, has apparently one GDP binding site per dimer.
Collapse
|
15
|
|
16
|
Carneheim C, Nedergaard J, Cannon B. Beta-adrenergic stimulation of lipoprotein lipase in rat brown adipose tissue during acclimation to cold. THE AMERICAN JOURNAL OF PHYSIOLOGY 1984; 246:E327-33. [PMID: 6372506 DOI: 10.1152/ajpendo.1984.246.4.e327] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Lipoprotein lipase activity in adult rats was investigated in animals subjected to cold and to different hormonal treatments. In contrast to changes in tissue wet weight and total protein content, which showed a lag time of about 1 day, lipoprotein lipase activity was markedly (fourfold) increased after only 4 h in the cold. Total lipoprotein lipase activity reached a plateau already after 1-3 days, whereas wet weight and protein content did not plateau until 3 wk. Neither insulin nor glucose injections could mimic the cold-induced increase in lipoprotein lipase activity seen after 4 h. However, the effect of norepinephrine injections was identical to the effect of cold. The beta-agonist isoprenaline was as effective as norepinephrine, whereas the alpha-agonist phenylephrine had no effect. The beta-antagonist propranolol inhibited the cold-induced increase in lipoprotein lipase activity. It is concluded that, in contrast to white adipose tissue, brown adipose tissue lipoprotein lipase is stimulated in vivo by a beta-adrenergic mechanism and that it is this beta-adrenergic mechanism that is responsible for the rapid recruitment of lipoprotein lipase during cold exposure.
Collapse
|
17
|
Trayhurn P, Richard D, Jennings G, Ashwell M. Adaptive changes in the concentration of the mitochondrial 'uncoupling' protein in brown adipose tissue of hamsters acclimated at different temperatures. Biosci Rep 1983; 3:1077-84. [PMID: 6320922 DOI: 10.1007/bf01120199] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The effect of acclimation at different temperatures on the activity of interscapular brown adipose tissue has been investigated in the hamster, a hibernator. Between 31 degrees and 4 degrees C the cytochrome oxidase activity of the tissue increased 4- to 5-fold, mitochondrial GDP binding per mg of mitochondrial protein doubled, and the amount of uncoupling protein rose from 1.7% to 5.4% of total mitochondrial protein. It is concluded that there are clear adaptive changes induced by temperature in brown adipose tissue of the hamster, but the changes are limited in comparison with those in the mouse.
Collapse
|
18
|
Ashwell M, Jennings G, Richard D, Stirling DM, Trayhurn P. Effect of acclimation temperature on the concentration of the mitochondrial 'uncoupling' protein measured by radioimmunoassay in mouse brown adipose tissue. FEBS Lett 1983; 161:108-12. [PMID: 6309573 DOI: 10.1016/0014-5793(83)80740-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effect of acclimation temperature on the concentration of the mitochondrial 'uncoupling' protein (Mr 32000) from brown adipose tissue of mice has been investigated. The uncoupling protein was measured by a specific radioimmunoassay. Between 33 degrees C (thermoneutrality) and -2 degrees C there was a progressive increase with decreasing environmental temperature in the amount of uncoupling protein. For mice at -2 degrees C the mitochondrial concentration of the protein was 9-times higher than at 33 degrees C, while the total amount of the protein in interscapular brown adipose tissue was estimated to be nearly 80-times greater at -2 degrees C compared to 33 degrees C.
Collapse
|
19
|
Sundin U, Nechad M. Trophic response of rat brown fat by glucose feeding: involvement of sympathetic nervous system. THE AMERICAN JOURNAL OF PHYSIOLOGY 1983; 244:C142-9. [PMID: 6299108 DOI: 10.1152/ajpcell.1983.244.3.c142] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Brown adipose tissue has earlier been suggested as an important site of the diet-induced thermogenesis that results from cafeteria feeding in rats. The aim of the present communication has been to see if any defined component of this diet can mimic the effects of the diet on the trophic response of brown fat and if these effects are mediated by the sympathetic nervous system. Rats fed a lipid emulsion did not show hypertrophy of brown adipose tissue. Rats fed a glucose solution, whether voluntarily or by force feeding, showed a clear trophic response of brown fat, as seen by the morphology of the tissue and its increased wet weight, increased protein content, increased total and specific cytochrome c oxidase activity, and increased mitochondrial guanosine diphosphate binding. Chemical sympathectomy of young rats by guanethidine prior to glucose feeding impaired the glucose-induced effects on brown fat. beta-Adrenergic blockade in adult rats also tended to depress the glucose effect. Consequently we conclude that chronic glucose ingestion can mimic cafeteria feeding with respect to the trophic response of brown fat and that an intact sympathetic nervous system is required for the mediation of the glucose effect to the brown adipose tissue.
Collapse
|
20
|
Nedergaard J, Alexson S, Cannon B. Cold adaptation in the rat: increased brown fat peroxisomal beta-oxidation relative to maximal mitochondrial oxidative capacity. THE AMERICAN JOURNAL OF PHYSIOLOGY 1980; 239:C208-16. [PMID: 7435608 DOI: 10.1152/ajpcell.1980.239.5.c208] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Brown fat hypertrophy in the rat resulting from cold adaptation is shown here to involve increased mitochondrial, peroxisomal, and lysosomal enzyme activities. Mitochondrial activity in homogenates of brown fat was estimated as cytochrome c oxidase. After 4 wk in the cold (+5 C), the total activity was 3-fold higher than in control rats, although the specific activity was somewhat lower. Peroxisomal activity was followed as cyanide-insensitive palmitoyl-CoA-dependent NAD+ reduction (palmitoyl-CoA oxidase) and as catalase. The total activity of both palmitoyl-CoA oxidase and catalase was more than 10-fold higher than in controls and the specific activity about 3-fold higher. Acid phosphatase, used as a lysosomal marker, showed a 6-fold higher total activity and almost twice as high specific activity. The relatively greater increase in peroxisomes and lysosomes compared with mitochondria indicates an involvement in thermogenesis also for these organelles.
Collapse
|