Production of glutamine and utilization of glutamate by rat subcutaneous adipose tissue in vivo

1994 ◽  
Vol 266 (1) ◽  
pp. E151-E154 ◽  
Author(s):  
T. J. Kowalski ◽  
M. Watford
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Sampling Technique ◽  
Calibration Method ◽  
Glutamine Metabolism ◽  
Whole Body ◽  
Arterial Blood ◽  
Subcutaneous Adipose

Information about adipose tissue amino acid metabolism is limited, with most data derived from studies in vitro. The purpose of this study was to further characterize the role of adipose tissue in glutamine metabolism in the rat in vivo. The extracellular concentrations of glutamine, glutamate, alanine, and ammonia were measured in the rat inguinal fat pad using a microdialysis sampling technique. A calibration method was used to accurately assess the extracellular levels of metabolites, and a comparison of these concentrations with those in arterial blood allowed determination of the net flux of each compound. The adipose tissue-arterial blood concentration differences were 122 +/- 19, 54 +/- 37, -61 +/- 21, and -28 +/- 13 microM for glutamine, alanine, glutamate, and ammonia, respectively, indicating a production of glutamine and an uptake of glutamate by subcutaneous adipose tissue. The magnitude of glutamine production suggests that adipose tissue may play a significant role in whole body glutamine homeostasis.

scholarly journals A Cross-Machine Comparison of Shear-Wave Speed Measurements Using 2D Shear-Wave Elastography in the Normal Female Breast

2021 ◽  
Vol 11 (20) ◽  
pp. 9391
Author(s):  
Emma Harris ◽  
Ruchi Sinnatamby ◽  
Elizabeth O’Flynn ◽  
Anna M. Kirby ◽  
Jeffrey C. Bamber
Keyword(s):  
Adipose Tissue ◽  
Shear Wave ◽  
Subcutaneous Adipose Tissue ◽  
Wave Speed ◽  
Shear Wave Elastography ◽  
Shear Wave Speed ◽  
Skin Region ◽  
Subcutaneous Adipose

Quantitative measures of radiation-induced breast stiffness are required to support clinical studies of novel breast radiotherapy regimens and exploration of personalised therapy, however, variation between shear-wave elastography (SWE) machines may limit the usefulness of shear-wave speed (cs) for this purpose. Mean cs measured in four healthy volunteers’ breasts and a phantom using 2D-SWE machines Acuson S2000 (Siemens Medical Solutions) and Aixplorer (Supersonic Imagine) were compared. Shear-wave speed was measured in the skin region, subcutaneous adipose tissue and parenchyma. cs estimates were on average 2.3% greater when using the Aixplorer compared to S2000 in vitro. In vivo, cs estimates were on average 43.7%, 36.3% and 49.9% significantly greater (p << 0.01) when using the Aixplorer compared to S2000, for skin region, subcutaneous adipose tissue and parenchyma, respectively. In conclusion, despite relatively small differences between machines observed in vitro, large differences in absolute measures of shear wave speed measured were observed in vivo, which may prevent pooling of cross-machine data in clinical studies of the breast.

401 MIGRATION AND THERAPEUTIC POTENTIAL OF PORCINE ADULT ADIPOSE-DERIVED MESENCHYMAL STEM CELLS

2010 ◽  
Vol 22 (1) ◽  
pp. 357 ◽  
Author(s):  
S. M. Wilson ◽  
E. Monaco ◽  
M. S. Goldwasser ◽  
S. G. Clark ◽  
W. L. Hurley ◽  
...  
Keyword(s):  
Stem Cells ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Adult Stem Cells ◽  
Bone Defects ◽  
Adipose Derived Stem Cells ◽  
Subcutaneous Adipose ◽  
Time Point

Bone marrow is one current source of adult stem cells for therapeutic purposes; however, the magnitude and accessibility of subcutaneous adipose tissue in humans make it an attractive alternative. Numerous in vitro studies have been conducted to determine how these cells act in vitro, but it is imperative to determine the vast abilities of these cells in vivo. The objective of this study was to evaluate in vivo migration and bone healing ability after transplanting adipose-derived stem cells (ADSC) in a swine model. Adipose-derived stem cells were isolated from subcutaneous adipose tissue of adult Yorkshire pigs and cultured in vitro. At 80 to 90% confluence/passage 3, the cells were trypsinized and labeled in suspension with carboxyfluorescein succinimidyl ester (CFDA-SE). This project included 20 pigs weighing between 63.5 and 81.7 kg. Bilateral mandibular osteoectomies with 10-mm defects were performed on each pig. Of the 20 pigs, half received a treatment of 2.5 million CFDA-SE labeled stem cells administered directly into each defect (DI), and the remaining half received a treatment of approximately 5 million CFDA-SE labeled stem cells through an ear vein injection via catheter (EVI). The time points were 1 h and 2 and 4 wk, with 2 pigs per time with the DI and EVI treatments. Pigs were slaughtered at each time, and spleen, liver, lung, kidney, ear vein, blood, and mandible tissues were collected. Blood samples were collected from the jugular vein with EDTA and processed via flow cytometry after collection. Tissues were fixed in 10% buffered formalin for histology. Fluorescent microscopy (CFDA-SE excitation/emission is 492/517 nm) has confirmed that transplanted ADSC do indeed migrate to a site of injury or trauma. Labeled cells were also present in blood collected from the 1-h time point group. Currently, we have not seen the presence of labeled ADSC in the other tissues (spleen, liver, lung, and kidney) after the 1-h time point. We did observe that ADSC administered by DI and EVI were able to significantly heal and regenerate bone defects within 4 wk post-surgery (P < 0.05, ANOVA with F-test), in contrast to bone defects in pigs that did not receive cell injections (control). Evidence of ADSC-related healing and bone regeneration was evident by gross visualization, dual-energy x-ray absorptiometry (DXA) and micro computer tomography (microCT) analysis. The clinical implications of these results are significant for treating many diseases in which inflammation or defects exist, such as cardiac disease, neurological disease, or traumatic injuries to both soft and hard tissue. If the adult stem cells can be harvested from fat, encouraged to produce bone or cartilage, and then reinserted into defects, treatment protocols for trauma victims could be developed that would reduce the need for alternate harvesting techniques for bone. This work was support by a grant from the Illinois Regenerative Medicine Institute (IDPH # 63080017).

scholarly journals In Vitro-Generated Hypertrophic-Like Adipocytes Displaying PPARG Isoforms Unbalance Recapitulate Adipocyte Dysfunctions In Vivo

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1284 ◽  
Author(s):  
Marianna Aprile ◽  
Simona Cataldi ◽  
Caterina Perfetto ◽  
Maria Rosaria Ambrosio ◽  
Paola Italiani ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Glucose Tolerance ◽  
Subcutaneous Adipose Tissue ◽  
Protein Quantification ◽  
Dominant Negative ◽  
Down Regulation ◽  
Molecular Features ◽  
Subcutaneous Adipose

Reduced neo-adipogenesis and dysfunctional lipid-overloaded adipocytes are hallmarks of hypertrophic obesity linked to insulin resistance. Identifying molecular features of hypertrophic adipocytes requires appropriate in vitro models. We describe the generation of a model of human hypertrophic-like adipocytes directly comparable to normal adipose cells and the pathologic evolution toward hypertrophic state. We generate in vitro hypertrophic cells from mature adipocytes, differentiated from human mesenchymal stem cells. Combining optical, confocal, and transmission electron microscopy with mRNA/protein quantification, we characterize this cellular model, confirming specific alterations also in subcutaneous adipose tissue. Specifically, we report the generation and morphological/molecular characterization of human normal and hypertrophic-like adipocytes. The latter displays altered morphology and unbalance between canonical and dominant negative (PPARGΔ5) transcripts of PPARG, paralleled by reduced expression of PPARγ targets, including GLUT4. Furthermore, the unbalance of PPARγ isoforms associates with GLUT4 down-regulation in subcutaneous adipose tissue of individuals with overweight/obesity or impaired glucose tolerance/type 2 diabetes, but not with normal weight or glucose tolerance. In conclusion, the hypertrophic-like cells described herein are an innovative tool for studying molecular dysfunctions in hypertrophic obesity and the unbalance between PPARγ isoforms associates with down-regulation of GLUT4 and other PPARγ targets, representing a new hallmark of hypertrophic adipocytes.

The use of microdialysis to characterize the endocrine production of human subcutaneous adipose tissue in vivo

2009 ◽  
Vol 155 (1-3) ◽  
pp. 156-162 ◽  
Author(s):  
Ivana Dostálová ◽  
Petra Kaválková ◽  
Denisa Haluzíková ◽  
Jitka Housová ◽  
Martin Matoulek ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Subcutaneous Adipose

Inflammation and impaired adipogenesis in hypertrophic obesity in man

2009 ◽  
Vol 297 (5) ◽  
pp. E999-E1003 ◽  
Author(s):  
Birgit Gustafson ◽  
Silvia Gogg ◽  
Shahram Hedjazifar ◽  
Lachmi Jenndahl ◽  
Ann Hammarstedt ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Subcutaneous Adipose Tissue ◽  
Molecular Mechanisms ◽  
Whole Body ◽  
Preadipocyte Differentiation ◽  
Metabolic Complications ◽  
Adipose Cell ◽  
Subcutaneous Adipose ◽  
Adipose Cell Size

Obesity is associated mainly with adipose cell enlargement in adult man (hypertrophic obesity), whereas the formation of new fat cells (hyperplastic obesity) predominates in the prepubertal age. Adipose cell size, independent of body mass index, is negatively correlated with whole body insulin sensitivity. Here, we review recent findings linking hypertrophic obesity with inflammation and a dysregulated adipose tissue, including local cellular insulin resistance with reduced IRS-1 and GLUT4 protein content. In addition, the number of preadipocytes in the abdominal subcutaneous adipose tissue capable of undergoing differentiation to adipose cells is reduced in hypertrophic obesity. This is likely to promote ectopic lipid accumulation, a well-known finding in these individuals and one that promotes insulin resistance and cardiometabolic risk. We also review recent results showing that TNFα, but not MCP-1, resistin, or IL-6, completely prevents normal adipogenesis in preadipocytes, activates Wnt signaling, and induces a macrophage-like phenotype in the preadipocytes. In fact, activated preadipocytes, rather than macrophages, may completely account for the increased release of chemokines and cytokines by the adipose tissue in obesity. Understanding the molecular mechanisms for the impaired preadipocyte differentiation in the subcutaneous adipose tissue in hypertrophic obesity is a priority since it may lead to new ways of treating obesity and its associated metabolic complications.

Thermogenic response to epinephrine in the forearm and abdominal subcutaneous adipose tissue

1992 ◽  
Vol 263 (5) ◽  
pp. E850-E855 ◽  
Author(s):  
L. Simonsen ◽  
J. Bulow ◽  
J. Madsen ◽  
N. J. Christensen
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Energy Expenditure ◽  
Oxygen Uptake ◽  
Glucose Uptake ◽  
Subcutaneous Adipose Tissue ◽  
Whole Body ◽  
Epinephrine Infusion ◽  
Basal Period ◽  
Subcutaneous Adipose

Whole body energy expenditure, thermogenic and metabolic changes in the forearm, and intercellular glucose concentrations in subcutaneous adipose tissue on the abdomen determined by microdialysis were measured during epinephrine infusion in healthy subjects. After a control period, epinephrine was infused at rates of 0.2 and 0.4 nmol.kg-1 x min-1. Whole body resting energy expenditure was 4.36 +/- 0.56 (SD) kJ/min. Energy expenditure increased to 5.14 +/- 0.74 and 5.46 +/- 0.79 kJ/min, respectively (P < 0.001), during the epinephrine infusions. Respiratory exchange ratio was 0.80 +/- 0.04 in the resting state and did not change. Local forearm oxygen uptake was 3.9 +/- 1.3 mumol.100 g-1 x min-1 in the basal period. During epinephrine infusion, it increased to 5.8 +/- 2.1 (P < 0.03) and 7.5 +/- 2.3 mumol.100 g-1 x min-1 (P < 0.001). Local forearm glucose uptake was 0.160 +/- 0.105 mumol.100 g-1 x min-1 and increased to 0.586 +/- 0.445 and 0.760 +/- 0.534 mumol.100 g-1 x min-1 (P < 0.025). The intercellular glucose concentration in the subcutaneous adipose tissue on the abdomen was equal to the arterial concentration in the basal period but did not increase as much during infusion of epinephrine, indicating glucose uptake in adipose tissue in this condition. If it is assumed that forearm skeletal muscle is representative for the average skeletal muscle, it can be calculated that on average 40% of the enhanced whole body oxygen uptake induced by infusion of epinephrine is taking place in skeletal muscle. It is proposed that adipose tissue may contribute to epinephrine-induced thermogenesis.

scholarly journals Is the resting rate of oxygen consumption of locomotor muscles in crustaceans limited by the low blood oxygenation strategy?

2001 ◽  
Vol 204 (5) ◽  
pp. 933-940 ◽  
Author(s):  
J. Forgue ◽  
A. Legeay ◽  
J.C. Massabuau
Keyword(s):  
Blood Oxygenation ◽  
Whole Body ◽  
Blood Gas ◽  
Astacus Leptodactylus ◽  
Night Time ◽  
Arterial Blood ◽  
Rate Of Oxygen Consumption ◽  
Locomotor Muscles

Numerous water-breathers exhibit a gas-exchange regulation strategy that maintains O(2) partial pressure, P(O2), in the arterial blood within the range 1–3 kPa at rest during the daytime. In a night-active crustacean, we examined whether this could limit the rate of O(2)consumption (M(O2)) of locomotor muscles and/or the whole body as part of a coordinated response to energy conservation. In the crayfish Astacus leptodactylus, we compared the in vitro relationship between the M(O2) of locomotor muscles as a function of the extracellular P(O2) and P(CO2) and in vivo circadian changes in blood gas tensions at various values of water P(O2). In vitro, the M(O2) of locomotor muscle, either at rest or when stimulated with CCCP, was O(2)-dependent up to an extracellular P(O2) of 8–10 kPa. In vivo, the existence of a night-time increase in arterial P(O2) of up to 4 kPa at water P(O2) values of 20 and 40 kPa was demonstrated, but an experimental increase in arterial P(O2) during the day did not lead to any rise in whole-body M(O2). This suggested that the low blood P(O2) in normoxia has no global limiting effect on daytime whole-body M(O2). The participation of blood O(2) status in shaping the circadian behaviour of crayfish is discussed.

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