Fat-Covered Islet Transplantation using Epididymal White Adipose Tissue

10.3791/62096 ◽  
2021 ◽  
Author(s):  
Naoaki Sakata ◽  
Gumpei Yoshimatsu ◽  
Ryo Kawakami ◽  
Shohta Kodama
Keyword(s):  
Adipose Tissue ◽  
Islet Transplantation ◽  
White Adipose Tissue ◽  
Epididymal White Adipose Tissue

scholarly journals Effects of Ca2+ and Mg2+ on the activity of pyruvate dehydrogenase phosphate phosphatase within toluene-permeabilized mitochondria

1987 ◽  
Vol 241 (2) ◽  
pp. 371-377 ◽  
Author(s):  
P J Midgley ◽  
G A Rutter ◽  
A P Thomas ◽  
R M Denton
Keyword(s):  
Adipose Tissue ◽  
Small Molecules ◽  
White Adipose Tissue ◽  
Pyruvate Dehydrogenase ◽  
Maximum Rate ◽  
Major Effect ◽  
Lag Phase ◽  
Inhibitory Effects ◽  
Highly Sensitive ◽  
Epididymal White Adipose Tissue

Mitochondria from rat epididymal white adipose tissue were made permeable to small molecules by toluene treatment and were used to investigate the effects of Mg2+ and Ca2+ on the re-activation of pyruvate dehydrogenase phosphate by endogenous phosphatase. Re-activation of fully phosphorylated enzyme after addition of 0.18 mM-Mg2+ showed a marked lag of 5-10 min before a maximum rate of reactivation was achieved. Increasing the Mg2+ concentration to 1.8 mM (near saturating) or the addition of 100 microM-Ca2+ resulted in loss of the lag phase, which was also greatly diminished if pyruvate dehydrogenase was not fully phosphorylated. It is concluded that, within intact mitochondria, phosphatase activity is highly sensitive to the degree of phosphorylation of pyruvate dehydrogenase and that the major effect of Ca2+ may be to overcome the inhibitory effects of sites 2 and 3 on the dephosphorylation of site 1. Apparent K0.5 values for Mg2+ and Ca2+ were determined from the increases in pyruvate dehydrogenase activity observed after 5 min. The K0.5 for Mg2+ was diminished from 0.60 mM at less than 1 nM-Ca2+ to 0.32 mM at 100 microM-Ca2+; at 0.18 mM-Mg2+, the K0.5 for Ca2+ was 0.40 microM. Ca2+ had little or no effect at saturating Mg2+ concentrations. Since effects of Ca2+ are readily observed in intact coupled mitochondria, it follows that Mg2+ concentrations within mitochondria are sub-saturating for pyruvate dehydrogenase phosphate phosphatase and hence less than 0.5 mM.

Effects of exercise training on adipogenesis of stromal-vascular fraction cells in rat epididymal white adipose tissue

2010 ◽  
pp. no-no ◽  
Author(s):  
Takuya Sakurai ◽  
Satohiro Endo ◽  
Daisuke Hatano ◽  
Junetsu Ogasawara ◽  
Takako Kizaki ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Exercise Training ◽  
White Adipose Tissue ◽  
Stromal Vascular Fraction ◽  
Epididymal White Adipose Tissue

scholarly journals Metformin induces oxidative stress in white adipocytes and raises uncoupling protein 2 levels

2008 ◽  
Vol 199 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Andrea Anedda ◽  
Eduardo Rial ◽  
M Mar González-Barroso
Keyword(s):  
Oxidative Stress ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Uncoupling Protein ◽  
Acid Oxidation ◽  
Protein Levels ◽  
White Adipocytes ◽  
Epididymal White Adipose Tissue ◽  
Amp Activated Protein Kinase

Metformin is a drug widely used to treat type 2 diabetes. It enhances insulin sensitivity by improving glucose utilization in tissues like liver or muscle. Metformin inhibits respiration, and the decrease in cellular energy activates the AMP-activated protein kinase that in turn switches on catabolic pathways. Moreover, metformin increases lipolysis and β-oxidation in white adipose tissue, thereby reducing the triglyceride stores. The uncoupling proteins (UCPs) are transporters that lower the efficiency of mitochondrial oxidative phosphorylation. UCP2 is thought to protect against oxidative stress although, alternatively, it could play an energy dissipation role. The aim of this work was to analyse the involvement of UCP2 on the effects of metformin in white adipocytes. We studied the effect of this drug in differentiating 3T3-L1 adipocytes and found that metformin causes oxidative stress since it increases the levels of reactive oxygen species (ROS) and lowers the aconitase activity. Variations in UCP2 protein levels parallel those of ROS. Metformin also increases lipolysis in these cells although only when the levels of ROS and UCP2 have decreased. Hence, UCP2 does not appear to be needed to facilitate fatty acid oxidation. Furthermore, treatment of C57BL/6 mice with metformin also augmented the levels of UCP2 in epididymal white adipose tissue. We conclude that metformin treatment leads to the overexpression of UCP2 in adipocytes to minimize the oxidative stress that is probably due to the inhibition of respiration caused by the drug.

scholarly journals Effects of 6-meals-a-day feeding and 6-meals-a-day feeding combined with adrenalectomy on daily gene expression rhythms in rat epididymal white adipose tissue

2015 ◽  
Vol 21 (1) ◽  
pp. 6-24 ◽  
Author(s):  
Yan Su ◽  
Ewout Foppen ◽  
Zhi Zhang ◽  
Eric Fliers ◽  
Andries Kalsbeek
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Epididymal White Adipose Tissue

scholarly journals The SCN Clock Governs Circadian Transcription Rhythms in Murine Epididymal White Adipose Tissue

2016 ◽  
Vol 31 (6) ◽  
pp. 577-587 ◽  
Author(s):  
Isa Kolbe ◽  
Jana Husse ◽  
Gabriela Salinas ◽  
Thomas Lingner ◽  
Mariana Astiz ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Clock Genes ◽  
Mutant Mice ◽  
Immune Functions ◽  
Whole Genome Microarray ◽  
Peripheral Clocks ◽  
Epididymal White Adipose Tissue ◽  
External Time

The circadian master pacemaker in the suprachiasmatic nucleus (SCN) orchestrates peripheral clocks in various organs and synchronizes them with external time, including those in adipose tissue, which displays circadian oscillations in various metabolic and endocrine outputs. Because our knowledge about the instructive role of the SCN clock on peripheral tissue function is based mainly on SCN lesion studies, we here used an alternative strategy employing the Cre/ loxP system to functionally delete the SCN clock in mice. We performed whole-genome microarray hybridizations of murine epididymal white adipose tissue (eWAT) RNA preparations to characterize the role of the SCN clock in eWAT circadian transcriptome regulation. Most of the rhythmic transcripts in control animals were not rhythmic in SCN mutants, but a significant number of transcripts were rhythmic only in mutant eWAT. Core clock genes were rhythmic in both groups, but as was reported before for other tissues, rhythms were dampened and phase advanced in mutant animals. In SCN-mutant mice, eWAT lost the rhythm of metabolic pathway–related transcripts, while transcripts gaining rhythms in SCN-mutant mice were associated with various immune functions. These data reveal a complex interaction of SCN-derived and local circadian signals in the regulation of adipose transcriptome programs.

Epididymal white adipose tissue after cold stress in rats II. Mitochondrial changes

1988 ◽  
Vol 101 (2-3) ◽  
pp. 199-209 ◽  
Author(s):  
Dragutin Loncˇar ◽  
Björn A. Afzelius ◽  
Barbara Cannon
Keyword(s):  
Adipose Tissue ◽  
Cold Stress ◽  
White Adipose Tissue ◽  
Epididymal White Adipose Tissue

scholarly journals Castration-induced changes in mouse epididymal white adipose tissue

2011 ◽  
Vol 345 (1-2) ◽  
pp. 58-67 ◽  
Author(s):  
Daniel Floryk ◽  
Shinji Kurosaka ◽  
Ryuta Tanimoto ◽  
Guang Yang ◽  
Alexei Goltsov ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Epididymal White Adipose Tissue ◽  
Induced Changes
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