Independent Influences of Central Fat and Skeletal Muscle Lipids on Insulin Sensitivity

2001 ◽  
Vol 9 (9) ◽  
pp. 535-543 ◽  
Author(s):  
Stuart M. Furler ◽  
Ann M. Poynten ◽  
Adamandia D. Kriketos ◽  
Andrew J. Lowy ◽  
Bronwyn A. Ellis ◽  
...  
Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1935-P
Author(s):  
SIMONA ZARINI ◽  
LEIGH PERREAULT ◽  
SEAN A. NEWSOM ◽  
DARCY E. KAHN ◽  
ANNA KEREGE ◽  
...  

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 156-OR
Author(s):  
SOFIYA GANCHEVA ◽  
MERIEM OUNI ◽  
CHRYSI KOLIAKI ◽  
TOMAS JELENIK ◽  
DANIEL F. MARKGRAF ◽  
...  

1966 ◽  
Vol 241 (11) ◽  
pp. 2626-2634 ◽  
Author(s):  
E.J. Masoro ◽  
L.B. Rowell ◽  
R.M. McDonald ◽  
B. Steiert

1986 ◽  
Vol 250 (5) ◽  
pp. E570-E575
Author(s):  
G. K. Grimditch ◽  
R. J. Barnard ◽  
S. A. Kaplan ◽  
E. Sternlicht

We examined the hypothesis that the exercise training-induced increase in skeletal muscle insulin sensitivity is mediated by adaptations in insulin binding to sarcolemmal (SL) insulin receptors. Insulin binding studies were performed on rat skeletal muscle SL isolated from control and trained rats. No significant differences were noted between groups in body weight or fat. An intravenous glucose tolerance test showed an increase in whole-body insulin sensitivity with training, and specific D-glucose transport studies on isolated SL vesicles indicated that this was due in part to adaptations in skeletal muscle. Enzyme marker analyses revealed no differences in yield, purity, or contamination of SL membranes between the two groups. Scatchard analyses indicated no significant differences in the number of insulin binding sites per milligram SL protein on the high-affinity (15.0 +/- 4.1 vs. 18.1 +/- 6.4 X 10(9)) or on the low-affinity portions (925 +/- 80 vs. 884 +/- 106 X 10(9)) of the curves. The association constants of the high-affinity (0.764 +/- 0.154 vs. 0.685 +/- 0.264 X 10(9) M-1) and of the low affinity sites (0.0096 +/- 0.0012 vs. 0.0102 +/- 0.0012 X 10(9) M-1) also were similar. These results do not support the hypothesis that the increased sensitivity to insulin after exercise training is due to changes in SL insulin receptor binding.


1996 ◽  
Vol 80 (6) ◽  
pp. 1963-1967 ◽  
Author(s):  
N. Nakai ◽  
Y. Shimomura ◽  
N. Ohsaki ◽  
J. Sato ◽  
Y. Oshida ◽  
...  

We examined the effects of exercise training initiated before maturation or after maturation on insulin sensitivity and glucose transporter GLUT-4 content in membrane fractions of skeletal muscle. Female Wistar rats (4 wk of age) were divided into sedentary and exercise-trained groups. At 12 wk of age, a subset of the trained animals (Tr) was killed along with a subset of sedentary controls (Sed). One-half of the remaining sedentary animals remained sedentary (Sed-Sed) while the other half began exercise training (Sed-Tr). The remaining rats in the original trained group continued to train (Tr-Tr). Euglycemic clamp (insulin infusion rate at 6 mU.kg body wt-1. min-1) was performed at 4, 12, and 27 wk. After euglycemic clamp in all animals except the 4-wk-old, hindlimb (gastrocnemius and part of quadriceps) muscles were removed for preparation of membrane fractions. In sedentary rats, glucose infusion rate (GIR) during euglycemic clamp was decreased from 15.9 mg.kg-1.min-1 at 4 wk of age to 9.8 mg.kg-1.min-1 at 12 wk of age and 9.1 mg.kg-1.min-1 at 27 wk of age. In exercise-trained rats, the GIR was not significantly decreased by maturation (at 12 wk) and further aging (at 27 wk). Initiation of exercise after maturation restored the GIR at 27 wk of age to the same levels as these for the corresponding exercise-trained rats. GLUT-4 content in plasma and intracellular membrane fractions of hindlimb muscle obtained just after euglycemic clamp showed the same trend as the results of GIR. These results suggest that exercise training prevented the maturation-induced decrease in insulin sensitivity. Improvement of insulin sensitivity caused by exercise training was attributed, at least in part, to the increase in insulin-sensitive GLUT-4 on the plasma membrane in skeletal muscle.


2013 ◽  
Vol 441 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Shin-ichi Ikeda ◽  
Yoshifumi Tamura ◽  
Saori Kakehi ◽  
Kageumi Takeno ◽  
Minako Kawaguchi ◽  
...  

2008 ◽  
Vol 28 (18) ◽  
pp. 5634-5645 ◽  
Author(s):  
Francesco Oriente ◽  
Luis Cesar Fernandez Diaz ◽  
Claudia Miele ◽  
Salvatore Iovino ◽  
Silvia Mori ◽  
...  

ABSTRACT We have examined glucose homeostasis in mice hypomorphic for the homeotic transcription factor gene Prep1. Prep1-hypomorphic (Prep1 i / i ) mice exhibit an absolute reduction in circulating insulin levels but normal glucose tolerance. In addition, these mice exhibit protection from streptozotocin-induced diabetes and enhanced insulin sensitivity with improved glucose uptake and insulin-dependent glucose disposal by skeletal muscle. This muscle phenotype does not depend on reduced expression of the known Prep1 transcription partner, Pbx1. Instead, in Prep1 i / i muscle, we find normal Pbx1 but reduced levels of the recently identified novel Prep1 interactor p160. Consistent with this reduction, we find a muscle-selective increase in mRNA and protein levels of PGC-1α, accompanied by enhanced expression of the GLUT4 transporter, responsible for insulin-stimulated glucose uptake in muscle. Indeed, using L6 skeletal muscle cells, we induced the opposite effects by overexpressing Prep1 or p160, but not Pbx1. In vivo skeletal muscle delivery of p160 cDNA in Prep1 i / i mice also reverses the molecular phenotype. Finally, we show that Prep1 controls the stability of the p160 protein. We conclude that Prep1 controls insulin sensitivity through the p160-GLUT4 pathway.


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