Rat epididymal adipocytes were incubated with 0, 0.1, and 1 mU sphingomyelinase/ml for 30 or 60 min, and glucose uptake and GLUT-1 and GLUT-4 translocation were assessed. Adipocytes exposed to 1 mU sphingomyelinase/ml exhibited a 173% increase in glucose uptake. Sphingomyelinase had no effect on the abundance of GLUT-1 in the plasma membrane of adipocytes. In contrast, 1 mU sphingomyelinase/ml ...

Objective: GLUT4 glucose transporter content and glucose transport capacity are closely correlated in muscle. The purpose of current study was to evaluate the effect of 6 weeks of resistance training and High-Intensity Interval Training (HITT) on Glut-4 gene expression in type 2 diabetes mellitus (T2DM) by high fat diet and STZ. Materials and Methods: This study was done on 32 male Wistar in B...

Insulin stimulates glucose transport in its target cells by recruiting the glucose transporter Glut 4 from an intracellular compartment to the cell surface. Previous studies have indicated that phosphatidylinositol 3-kinase (PI 3-kinase) is a necessary step in this insulin action. We have investigated whether PI 3-kinase activation is sufficient to promote Glut 4 translocation in transiently tr...

Gaster, M., P. Poulsen, A. Handberg, H. D. Schrøder, and H. Beck-Nielsen. Direct evidence of fiber type-dependent GLUT-4 expression in human skeletal muscle. Am J Physiol Endocrinol Metab 278: E910–E916, 2000.—GLUT-4 expression in individual fibers of human skeletal muscles in younger and older adults was studied. Furthermore, the dependency of insulin-stimulated glucose uptake on fiber type di...

Glucose transporter (GLUT) modulation can be an important mechanism that contributes to adaptation to hypoxic stress, but little is known about GLUT modulation in heart and skeletal muscle with prolonged hypoxia. In this work, the effect of chronic hypoxia on GLUT-4 and GLUT-1 mRNA and protein was studied in these two tissues in the adult and during development. Hypoxia (fractional inspired O2 ...

We measured net fetal glucose uptake rate from the placenta, shown previously to be equal to total fetal glucose utilization rate (GUR(f)) and proportional to fetal hindlimb skeletal muscle glucose utilization, under normal conditions and after 1, 2.5, and 24 h of selective hyperglycemia increasing G or selective hyperinsulinemia increasing I. We simultaneously measured the amount of Glut 1 and...

The purpose of this study was to investigate the role of insulin on skeletal muscle GLUT-4 protein expression and glycogen storage after postexercise carbohydrate supplementation. Male Sprague-Dawley rats were randomly assigned to one of six treatment groups: sedentary control (Con), Con with streptozocin (Stz/C), immediately postexercise (Ex0), Ex0 with Stz (Stz/Ex0), 5-h postexercise (Ex5), a...

Yu, Bo, Laurie A. Poirier, and Laura E. Nagy. Mobilization of GLUT-4 from intracellular vesicles by insulin and K1 depolarization in cultured H9c2 myotubes. Am. J. Physiol. 277 (Endocrinol. Metab. 40): E259–E267, 1999.—The insulinresponsive glucose transporter, GLUT-4, moves from an intracellular compartment to the cell surface in response to insulin and/or muscle contraction. Treatment of H9c2...

We examined the effects of epinephrine (25, 50, and 150 nM) on 1) basal and insulin-stimulated 3- O-methylglucose (3-MG) transport in perfused rat muscles and 2) GLUT-4 in skeletal muscle plasma membranes. Insulin increased glucose transport 330-600% in three types of skeletal muscle [white (WG) and red (RG) gastrocnemius and soleus (SOL)]. Glucose transport was also increased by epinephrine (2...

Reduced calorie intake [calorie restriction (CR); 60% of ad libitum (AL)] leads to enhanced glucose transport without altering total GLUT-4 glucose transporter abundance in skeletal muscle. Therefore, we tested the hypothesis that CR (20 days) alters the subcellular distribution of GLUT-4. Cell surface GLUT-4 content was higher in insulin-stimulated epitrochlearis muscles from CR vs. AL rats. T...