Dominic Stone
Glucose uptake in muscle is a function of different regulatory steps. These include the delivery of glucose from the blood to the interstitial space, transmembrane transport from the interstitial space to the inside of the muscle cell, and intracellular metabolism of the glucose. During exercise, the major metabolic fate of blood glucose after entry into skeletal muscle cells is glycolysis and subsequent oxidation. The increase in skeletal muscle glucose uptake during exercise results from a coordinated increase in rates of glucose delivery, surface membrane glucose transport, and intracellular substrate flux through glycolysis.
| Characteristics | Values |
|---|---|
| How muscle takes up glucose | Glucose is taken up by skeletal muscle from the extracellular fluid into the cell via a surface membrane sugar transport protein |
| Sugar transport proteins in mammalian cells | The solute carrier family 2 (gene family SLC2) which consists of fourteen facilitative glucose transporters (GLUTs 1–14); and the solute carrier family 5 (gene family SLC5) which consists of six sodium-dependent glucose co-transporters (SGLTs 1–6:) |
| Increase in skeletal muscle glucose uptake during exercise | Results from a coordinated increase in rates of glucose delivery (higher capillary perfusion), surface membrane glucose transport, and intracellular substrate flux through glycolysis |
Explore related products
What You'll Learn
The role of exercise intensity
Exercise intensity is the most influential factor for the magnitude of increase in muscle glucose uptake during exercise. The higher the exercise intensity, the greater the skeletal muscle glucose uptake. This is likely due to a combination of greater fibre recruitment and higher metabolic stress on active muscle fibres at higher exercise intensities.
During exercise, the major metabolic fate of blood glucose after entry into skeletal muscle cells is glycolysis and subsequent oxidation. The increase in skeletal muscle glucose uptake during exercise results from a coordinated increase in rates of glucose delivery (higher capillary perfusion), surface membrane glucose transport, and intracellular substrate flux through glycolysis.
Glucose uptake in muscle is a function of different regulatory steps, including the delivery of glucose from the blood to the interstitial space, transmembrane transport from the interstitial space to the inside of the muscle cell, and intracellular metabolism of the glucose. In most cases, transmembrane glucose transport is considered to be the limiting step.
Skeletal muscle takes up glucose from the extracellular fluid into the cell via a surface membrane sugar transport protein. There are two major families of sugar transport proteins found in mammalian cells: the solute carrier family 2 (gene family SLC2), which consists of fourteen facilitative glucose transporters (GLUTs 1–14), and the solute carrier family 5 (gene family SLC5), which consists of six sodium-dependent glucose co-transporters (SGLTs 1–6).
Ultrasound Technology: Detecting Muscle Knots and Their Treatment
You may want to see also
Explore related products
The role of GLUT4
Glucose is taken up by skeletal muscle from the extracellular fluid into the cell via a surface membrane sugar transport protein. There are two major families of sugar transport proteins found in mammalian cells: (1) The solute carrier family 2 (gene family SLC2) which consists of fourteen facilitative glucose transporters (GLUTs 1–14); and (2) the solute carrier family 5 (gene family SLC5) which consists of six sodium-dependent glucose co-transporters (SGLTs 1–6).
GLUT4 is one of the fourteen facilitative glucose transporters (GLUTs 1–14) that make up the solute carrier family 2 (gene family SLC2). It is a protein that is found in the cell membrane of skeletal muscle cells and is responsible for the transport of glucose into the cell. GLUT4 is unique among the GLUTs in that it is regulated by insulin. When insulin levels are high, GLUT4 is transported to the cell membrane, where it facilitates the uptake of glucose into the cell. When insulin levels are low, GLUT4 is internalised and recycled within the cell, reducing the uptake of glucose.
The mechanism behind the movement of GLUT4 to surface membranes and the subsequent increase in transport by muscle contractions is largely unresolved. However, it is likely to occur through intracellular signalling involving Ca2+-calmodulin-dependent protein kinase, 5′-AMP-activated protein kinase, and possibly protein kinase C.
In summary, GLUT4 plays a critical role in the uptake of glucose into skeletal muscle cells, particularly during exercise when glucose uptake is increased. The regulation of GLUT4 by insulin ensures that glucose uptake is matched to the metabolic needs of the cell.
Walking: Toning Your Stomach and Improving Core Strength
You may want to see also
Explore related products
The role of glucose transport proteins
Glucose uptake in muscle is a function of different regulatory steps. These include the delivery of glucose from the blood to the interstitial space, transmembrane transport from the interstitial space to the inside of the muscle cell, and the intracellular metabolism of the glucose. Transmembrane glucose transport is considered to be the limiting step in most cases.
There are two major families of sugar transport proteins found in mammalian cells: the solute carrier family 2 (gene family SLC2) and the solute carrier family 5 (gene family SLC5). The former consists of fourteen facilitative glucose transporters (GLUTs 1–14), while the latter consists of six sodium-dependent glucose co-transporters (SGLTs 1–6).
The increase in skeletal muscle glucose uptake during exercise results from a coordinated increase in rates of glucose delivery, surface membrane glucose transport, and intracellular substrate flux through glycolysis. During dynamic exercise, the turnover of ATP in skeletal muscle increases greatly and is fuelled by the catabolism of carbohydrates (intramuscular glycogen, blood glucose) and fatty acids (intramuscular triglycerides, blood lipids).
The mechanism behind the movement of GLUT4 to surface membranes and the subsequent increase in transport by muscle contractions is largely unresolved. However, it is likely to occur through intracellular signalling involving Ca2+-calmodulin-dependent protein kinase, 5′-AMP-activated protein kinase, and possibly protein kinase C.
Muscle Water Storage: How Much and Why?
You may want to see also
Explore related products
The role of glycogen
Glucose uptake in muscle is a function of different regulatory steps. These include the delivery of glucose from the blood to the interstitial space, transmembrane transport from the interstitial space to the inside of the muscle cell, and intracellular metabolism of the glucose. In most cases, transmembrane glucose transport is considered to be the limiting step.
During exercise, the major metabolic fate of blood glucose after entry into skeletal muscle cells is glycolysis and subsequent oxidation. The increase in skeletal muscle glucose uptake during exercise results from a coordinated increase in rates of glucose delivery, surface membrane glucose transport, and intracellular substrate flux through glycolysis. The mechanism behind the movement of GLUT4 to surface membranes and the subsequent increase in transport by muscle contractions is largely unresolved, but it is likely to occur through intracellular signalling involving Ca2+-calmodulin-dependent protein kinase, 5′-AMP-activated protein kinase, and possibly protein kinase C.
The Intriguing Flatness of Muscles Explained
You may want to see also
Explore related products
The role of glycolysis
Glucose uptake in muscle is a function of different regulatory steps. The first step is the delivery of glucose from the blood to the interstitial space. The second step is transmembrane transport from the interstitial space to the inside of the muscle cell. The third step is the intracellular metabolism of the glucose. In most cases, the second step is considered to be the limiting step.
Animal Muscles: The Science of Movement and Contraction
You may want to see also
Frequently asked questions
Muscle takes up glucose from the extracellular fluid into the cell via a surface membrane sugar transport protein.
Exercise intensity. The higher the exercise intensity, the greater the skeletal muscle glucose uptake.
Glycolysis and subsequent oxidation.
Glycogen.
The solute carrier family 2 (gene family SLC2) and the solute carrier family 5 (gene family SLC5).
