How Is Glucose Stored In The Liver?
The liver is large and in charge. The dark reddish-brown organ sits in the upper right abdomen and, at about 3 pounds, is the largest one inside the body (the skin is the largest organ overall). The liver manages a dizzying array of tasks, including digesting fats, making and storing glucose, and serving as the body's detox center. Glucose Warehouse The liver is an insulin-guided organ: Its behavior changes depending on the level of the hormone insulin in the body and how sensitive the liver is to that insulin. After eating, blood glucose levels rise, which in people without diabetes triggers the pancreas to release insulin into the blood. Insulin is the signal for the body to absorb glucose from the blood. Most cells just use the glucose to supply them with energy. But the liver has a special job when it comes to glucose. When levels of glucose (and consequently insulin) are high in the blood, the liver responds to the insulin by absorbing glucose. It packages the sugar into bundles called glycogen. These glucose granules fill up liver cells, so the liver is like a warehouse for excess glucose. When glucose levels drop, insulin production falls, too. The shortage of insulin in the blood is the signal that the liver needs to liquidate its assets, sending its glucose stores back into the blood to keep the body well fed between meals and overnight. The liver doles out stored glucose and has the singular ability to make glucose from scratch. This is a critical function that keeps people alive when food is scarce. In people with diabetes, however, the liver doesn't process and produce glucose normally, adding to the challenge of blood glucose control. The liver can't directly detect blood glucose levels; it knows only what insulin tells it. So, if there is a shortage of ins Continue reading >>
Why Diabetics Over Produce Sugar In The Liver
Why Diabetics Over Produce Sugar in the Liver Type 2 diabetics often suffer from an over-production of sugar within the liver, a response to falling blood glucose levels. This potentially dangerous mechanism was poorly understood until recently, when researchers uncovered the role that a certain master regulator plays in sugar production within the liver. While an inability to regulate blood glucose levels, due to resistance to insulin produced by pancreatic beta cells, is the primary mechanism that leads to and enhances type 2 diabetes, the liver plays a large role as well. Beta-cells, in a healthy body, produce insulin, which helps regulate blood glucose levels, but the liver itself directly responds to low blood glucose levels by producing more sugar. In type 2 diabetics, who suffer from insulin resistance (and therefore dysfunctional regulation of blood glucose with insulin), the liver often has a tendency to produce sugar when not really needed, which can cause potential harm. In other words, the liver continues to produce sugar past what it should, because insulin is not regulating the sugar already being produced, in type 2 diabetics. To illustrate the role that the liver plays in type 2 diabetics, researcher Dr. Jenny Gunton explains that over-production of sugar within the liver is why many diabetics wake up with higher blood glucose levels than they had when going to sleep: It upsets people when their blood sugar behaves as if theyre getting up in the night and having a really big snack. I have to tell them its just one of those unfair things about having diabetes. Researchers looked at ARNT, a so-called master regulator, which is known to play a large role in insulin production and blood glucose control. Past research by the same research team demonstrated t Continue reading >>
Blood Sugar Regulation
Ball-and-stick model of a glucose molecule Blood sugar regulation is the process by which the levels of blood sugar, primarily glucose, are maintained by the body within a narrow range. This tight regulation is referred to as glucose homeostasis. Insulin, which lowers blood sugar, and glucagon, which raises it, are the most well known of the hormones involved, but more recent discoveries of other glucoregulatory hormones have expanded the understanding of this process. Mechanisms Blood sugar regulation the flatline is the level needed the sine wave the fluctuations. Blood sugar levels are regulated by negative feedback in order to keep the body in balance. The levels of glucose in the blood are monitored by many tissues, but the cells in the pancreatic islets are among the most well understood and important. Glucagon If the blood glucose level falls to dangerous levels (as during very heavy exercise or lack of food for extended periods), the alpha cells of the pancreas release glucagon, a hormone whose effects on liver cells act to increase blood glucose levels. They convert glycogen into glucose (this process is called glycogenolysis). The glucose is released into the bloodstream, increasing blood sugar. Hypoglycemia, the state of having low blood sugar, is treated by restoring the blood glucose level to normal by the ingestion or administration of dextrose or carbohydrate foods. It is often self-diagnosed and self-medicated orally by the ingestion of balanced meals. In more severe circumstances, it is treated by injection or infusion of glucagon. Insulin When levels of blood sugar rise, whether as a result of glycogen conversion, or from digestion of a meal, a different hormone is released from beta cells found in the Islets of Langerhans in the p Continue reading >>
Schematic two-dimensional cross-sectional view of glycogen: A core protein of glycogenin is surrounded by branches of glucose units. The entire globular granule may contain around 30,000 glucose units. A view of the atomic structure of a single branched strand of glucose units in a glycogen molecule. Glycogen (black granules) in spermatozoa of a flatworm; transmission electron microscopy, scale: 0.3 µm Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in humans, animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body. Glycogen functions as one of two forms of long-term energy reserves, with the other form being triglyceride stores in adipose tissue (i.e., body fat). In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle. In the liver, glycogen can make up from 5–6% of the organ's fresh weight and the liver of an adult weighing 70 kg can store roughly 100–120 grams of glycogen. In skeletal muscle, Glycogen is found in a low concentration (1–2% of the muscle mass) and the skeletal muscle of an adult weighing 70 kg can store roughly 400 grams of glycogen. The amount of glycogen stored in the body—particularly within the muscles and liver—mostly depends on physical training, basal metabolic rate, and eating habits. Small amounts of glycogen are also found in other tissues and cells, including the kidneys, red blood cells, white blood cells,[medical citation needed] and glial cells in the brain. The uterus also stores glycogen during pregnancy to nourish the embryo. Approximately 4 grams of glucose are present in the blood of humans at all times; in fasted individuals, blood glucos Continue reading >>
How Sugar Messes Up Your Liver And Gives You Diabetes
Modern man is plagued with many diseases that you will not find in some "primitive" populations like modern hunter-gatherers. These include obesity, heart disease, some cancers and last but not least, type II diabetes... which has reached epidemic proportions in the past few decades and now afflicts about 300 million people worldwide. This disease is a common cause of early death, blindness, amputation and a severely decreased quality of life... and it is advancing rapidly, every single year. In the video above, Dr. Robert H. Lustig and Dr. Elissa S. Epel explain how excess sugar can mess up liver metabolism and ultimately lead to diabetes. Dr. Lustig recently took part in a study where they examined the associations between sugar consumption and diabetes in 175 countries (1). They found very clear associations, where each 150 kcal (about one can of soda) per day of sugar increased the prevalence of diabetes by 1.1%. To put this number in perspective, if all of the U.S. added one can of soda to their daily diet, almost 3.5 million more people would become diabetic. In this study, added sugar was the only part of the diet that correlated with diabetes when they adjusted for confounding factors. These types of studies are so-called observational studies, which can not prove that one thing caused another, it can only show that they are correlated. However, there are other lines of evidence linking sugar to the development of type II diabetes and this specifically involves how sugar affects the liver. Sugar is composed of two molecules... glucose and fructose. Glucose can be metabolized by every cell in the body and if we don't get it from the diet, our bodies make it. However, fructose is different. The only organ that can metabolize sugar is the liver, because only the li Continue reading >>
Key Regulator Of Blood Glucose Levels Discovered
Key regulator of blood glucose levels discovered La Jolla, CA – In many patients with type 2 diabetes, the liver acts like a sugar factory on overtime, churning out glucose throughout the day, even when blood sugar levels are high. Scientists at the Salk Institute for Biological Studies discovered a key cellular switch that controls glucose production in liver cells. This switch may be a potential new target for the development of highly specific diabetes drugs that signal the liver to reduce the production of sugar. The Salk researchers, led by Marc Montminy, a professor in the Clayton Foundation Laboratories for Peptide Biology, published their findings in the Sept. 7th online issue of Nature. “It is very exciting to understand how glucose production in the liver is regulated. Now, we can try to improve the way how type 2 diabetics handle blood sugar,” says Montminy. The newly discovered switch, a protein named TORC2, turns on the expression of genes necessary for glucose production in liver cells. When describing glucose’s role in health and disease, Montminy compares the human body to a hybrid car that runs on a mix of fuels depending on its activity status: gas, or glucose, is used for high-energy activities, and battery power, or body fat, for low-energy activities. During the day, when food refuels the “gas tank,” the body burns mainly glucose, and during sleep, it burns primarily fat. The body switches from glucose to fat burning mainly in response to two key hormones – insulin and glucagon – that are produced by the pancreas. During feeding, the pancreas releases insulin, which promotes the burning of glucose. At night, however, the pancreas releases glucagon into the bloodstream, which signals the body to fire up the fat burner. But even during Continue reading >>
How Does The Liver Regulate Blood Sugar Level?
The Liver absorbs Glucose after meals, storing it as Glycogen in response to Insulin, a Hormone released by the Pancreas when Blood sugar is high. In between meals, the liver raises blood sugar by hydrolyzing glycogen and releasing glucose in response to Glucagon, the antagonistic hormone released by the pancreas when blood sugar is low. Below is a diagram showing how the Endocrine system controls the Homeostatic feedback loop involved in keeping blood sugar even. Ask New Question Continue reading >>
What Is Glucose?
Glucose comes from the Greek word for "sweet." It's a type of sugar you get from foods you eat, and your body uses it for energy. As it travels through your bloodstream to your cells, it's called blood glucose or blood sugar. Insulin is a hormone that moves glucose from your blood into the cells for energy and storage. People with diabetes have higher-than-normal levels in their blood. Either they don't have enough insulin to move it through or their cells don't respond to insulin as well as they should. High blood glucose for a long period of time can damage your kidneys, eyes, and other organs. How Your Body Makes Glucose It mainly comes from foods rich in carbohydrates, like bread, potatoes, and fruit. As you eat, food travels down your esophagus to your stomach. There, acids and enzymes break it down into tiny pieces. During that process, glucose is released. It goes into your intestines where it's absorbed. From there, it passes into your bloodstream. Once in the blood, insulin helps glucose get to your cells. Energy and Storage Your body is designed to keep the level of glucose in your blood constant. Beta cells in your pancreas monitor your blood sugar level every few seconds. When your blood glucose rises after you eat, the beta cells release insulin into your bloodstream. Insulin acts like a key, unlocking muscle, fat, and liver cells so glucose can get inside them. Most of the cells in your body use glucose along with amino acids (the building blocks of protein) and fats for energy. But it's the main source of fuel for your brain. Nerve cells and chemical messengers there need it to help them process information. Without it, your brain wouldn't be able to work well. After your body has used the energy it needs, the leftover glucose is stored in little bundles Continue reading >>
Low Levels Of Glucose Cause Liver Dump?
I was reading Blood Sugar 101, and it mentions that low levels of insulin will cause the liver to dump glucose. I always though glucogon and stress hormones were the only ones to cause liver dumps. That is interesting, insulin resitance makes insulin appear to be a lower levels than normal, more information to justify moderate cardio to control liver response. The way I understand it, glucagon is a hormone in your pancreas. It is there to prevent lows so during the day when we are not eating, your pancreas produces glucagon which then sends a signal to the liver to convert glycogen to glucose. This is a very natural process and goes on many times during the day. Even if you have impaired beta cells, you still have a stong glucagon response. Your body is designed to keep you alive, all these hormones work in conjuction with each other. Sometimes the signals go wacky and that is when we see liver dumps when we are not really low. Many T 2's experience this. Metformin helps limit these spikes in the liver. D.D. Family Glucose Disregulation since 2005 The liver dumps glucose when glucagon rises and insulin goes low. If glucagon is present, but insulin is elevated, then the liver dump is suppressed. This is why insulin dependent diabetics have hypo problems, the normal signalling to dump blood sugar is suppressed by the external insulin. The way I understand it, glucagon is a hormone in your pancreas. It is there to prevent lows so during the day when we are not eating, your pancreas produces glucagon which then sends a signal to the liver to convert glycogen to glucose. This is a very natural process and goes on many times during the day. Even if you have impaired beta cells, you still have a stong glucagon response. Your body is designed to keep you alive, all these hormo Continue reading >>
Healing Leaky Livers
It may surprise you to know that, for many people, Type 2 diabetes is primarily a liver disease. The pancreas damage comes later. Is there anything we can do to heal a diabetic liver? Liver issues in diabetes are complicated. An article in the journal Clinical Diabetes explained that diabetes can cause liver disease; liver disease can cause diabetes; or both can arise together from other causes. Whichever comes first, the sick liver may produce way too much glucose, enough to overwhelm the body’s insulin. Why would a liver start pumping out unneeded glucose? Unhealthy livers tend to have a lot of fat in them, a condition called nonalcoholic fatty liver disease, or NAFLD. You don’t have to be fat to have a fatty liver (although overweight and obesity are risk factors). Thin people get it too, and the causes of NAFLD are unknown. Some are thought to be genetic. However, a recent animal study published in the journal PLOS One found that prenatal exposure to alcohol (from a mother who drank while pregnant) is strongly associated diabetes-like glucose production by the liver. There are probably other causes as well, including environmental chemicals and possibly unhealthy diets. A rat study in the Journal of Biological Chemistry found that fatty livers became more resistant to insulin. The researchers found processes by which insulin normally tells the liver to stop producing unwanted glucose. Excess fat in the liver seemed to block these processes, so too much glucose was produced. Human livers apparently act the same way. An Italian study in The American Journal of Medicine found that subjects with NAFLD had high fasting and postmeal insulin levels, high insulin resistance, and high triglyceride levels. (Triglycerides are a kind of blood fat.) High insulin levels can b Continue reading >>
Energy Metabolism In The Liver
Go to: Introduction The liver is a key metabolic organ which governs body energy metabolism. It acts as a hub to metabolically connect to various tissues, including skeletal muscle and adipose tissue. Food is digested in the gastrointestinal (GI) tract, and glucose, fatty acids, and amino acids are absorbed into the bloodstream and transported to the liver through the portal vein circulation system. In the postprandial state, glucose is condensed into glycogen and/or converted into fatty acids or amino acids in the liver. In hepatocytes, free fatty acids are esterified with glycerol-3-phosphate to generate triacylglycerol (TAG). TAG is stored in lipid droplets in hepatocytes or secreted into the circulation as very low-density lipoprotein (VLDL) particles. Amino acids are metabolized to provide energy or used to synthesize proteins, glucose, and/or other bioactive molecules. In the fasted state or during exercise, fuel substrates (e.g. glucose and TAG) are released from the liver into the circulation and metabolized by muscle, adipose tissue, and other extrahepatic tissues. Adipose tissue produces and releases nonesterified fatty acids (NEFAs) and glycerol via lipolysis. Muscle breaks down glycogen and proteins and releases lactate and alanine. Alanine, lactate, and glycerol are delivered to the liver and used as precursors to synthesize glucose (gluconeogenesis). NEFAs are oxidized in hepatic mitochondria through fatty acid β oxidation and generate ketone bodies (ketogenesis). Liver-generated glucose and ketone bodies provide essential metabolic fuels for extrahepatic tissues during starvation and exercise. Liver energy metabolism is tightly controlled. Multiple nutrient, hormonal, and neuronal signals have been identified to regulate glucose, lipid, and amino acid me Continue reading >>
How Does The Liver Control Glucose In The Blood?
Your body needs a constant supply of glucose, or sugar, for cells to have energy, so it requires a readily available reservoir to keep blood glucose in balance. One of the liver’s main roles in the body is controlling the amount of glucose circulating in the blood. By storing excess glucose as glycogen and creating new glucose from proteins and fat byproducts, the liver is able to maintain balanced glucose levels in your body at all times. Video of the Day When you eat carbohydrates, the body releases glucose into the bloodstream immediately, triggering the production of insulin. The body cannot be in a state of constant consumption, so when insulin levels are high enough, the body links long chains of glucose together into a compound called glycogen, which is then stored in the liver and the muscles. The liver uses this stored glucose energy as its main reservoir for releasing glucose into the bloodstream when levels drop. Breakdown of Glycogen Blood glucose levels drop when you're not eating, such as during sleep or between meals. This low blood sugar signals the liver to produce glucose and release it back into the bloodstream. The liver favors glycogen as its primary source since it is efficiently broken down into glucose in a process known as glycogenolysis. In this process, the liver breaks the bonds that hold glucose molecules together as glycogen, degrading most but not all of the glycogen molecule. Effects of Insulin Resistance When your body is chronically subjected to high levels of blood sugar and insulin, such as after you've eaten an excessive amount of foods high in sugar, it develops a resistance to the hormone, and the liver cannot respond properly, eventually leading to type-2 diabetes if the resistance is not controlled. According to a study publish Continue reading >>
How Does The Liver Work?
The liver is one of the largest organs in the body. It has many important metabolic functions. It converts the nutrients in our diets into substances that the body can use, stores these substances, and supplies cells with them when needed. It also takes up toxic substances and converts them into harmless substances or makes sure they are released from the body. The human adult liver weighs about 1.4 kg (3.1 pounds) and is found in the right upper abdomen, below the diaphragm. It takes up most of the space under the ribs and some space in the left upper abdomen, too. Viewed from the outside, a larger right lobe and smaller left lobe can be distinguished. The two lobes are separated by a band of connective tissue that anchors the liver to the abdominal cavity. The gallbladder, where bile is stored, is found in a small hollow on the underside of the liver. Liver tissue is made up of lots of smaller units of liver cells called lobules. Many canals carrying blood and bile run between the liver cells. Blood coming from the digestive organs flows through the portal vein to the liver, carrying nutrients, medication and also toxic substances. Once they reach the liver, these substances are processed, stored, altered, detoxified, and passed back into the blood or released in the bowel to be eliminated. In this way the liver can, for example, remove alcohol from your blood and get rid of by-products from the breakdown of medications. With the help of vitamin K, the liver produces proteins that are important in blood clotting. It is also one of the organs that break down old or damaged blood cells. The liver plays a central role in all metabolic processes in the body. In fat metabolism the liver cells break down fats and produce energy. They also produce about 800 to 1,000 ml of bi Continue reading >>
The Liver & Blood Sugar
During a meal, your liver stores sugar for later. When you’re not eating, the liver supplies sugar by turning glycogen into glucose in a process called glycogenolysis. The liver both stores and produces sugar… The liver acts as the body’s glucose (or fuel) reservoir, and helps to keep your circulating blood sugar levels and other body fuels steady and constant. The liver both stores and manufactures glucose depending upon the body’s need. The need to store or release glucose is primarily signaled by the hormones insulin and glucagon. During a meal, your liver will store sugar, or glucose, as glycogen for a later time when your body needs it. The high levels of insulin and suppressed levels of glucagon during a meal promote the storage of glucose as glycogen. The liver makes sugar when you need it…. When you’re not eating – especially overnight or between meals, the body has to make its own sugar. The liver supplies sugar or glucose by turning glycogen into glucose in a process called glycogenolysis. The liver also can manufacture necessary sugar or glucose by harvesting amino acids, waste products and fat byproducts. This process is called gluconeogenesis. When your body’s glycogen storage is running low, the body starts to conserve the sugar supplies for the organs that always require sugar. These include: the brain, red blood cells and parts of the kidney. To supplement the limited sugar supply, the liver makes alternative fuels called ketones from fats. This process is called ketogenesis. The hormone signal for ketogenesis to begin is a low level of insulin. Ketones are burned as fuel by muscle and other body organs. And the sugar is saved for the organs that need it. The terms “gluconeogenesis, glycogenolysis and ketogenesis” may seem like compli Continue reading >>
The Liver And Blood Glucose Levels
Tweet Glucose is the key source of energy for the human body. Supply of this vital nutrient is carried through the bloodstream to many of the body’s cells. The liver produces, stores and releases glucose depending on the body’s need for glucose, a monosaccharide. This is primarily indicated by the hormones insulin - the main regulator of sugar in the blood - and glucagon. In fact, the liver acts as the body’s glucose reservoir and helps to keep your circulating blood sugar levels and other body fuels steady and constant. How the liver regulates blood glucose During absorption and digestion, the carbohydrates in the food you eat are reduced to their simplest form, glucose. Excess glucose is then removed from the blood, with the majority of it being converted into glycogen, the storage form of glucose, by the liver’s hepatic cells via a process called glycogenesis. Glycogenolysis When blood glucose concentration declines, the liver initiates glycogenolysis. The hepatic cells reconvert their glycogen stores into glucose, and continually release them into the blood until levels approach normal range. However, when blood glucose levels fall during a long fast, the body’s glycogen stores dwindle and additional sources of blood sugar are required. To help make up this shortfall, the liver, along with the kidneys, uses amino acids, lactic acid and glycerol to produce glucose. This process is known as gluconeogenesis. The liver may also convert other sugars such as sucrose, fructose, and galactose into glucose if your body’s glucose needs not being met by your diet. Ketones Ketones are alternative fuels that are produced by the liver from fats when sugar is in short supply. When your body’s glycogen storage runs low, the body starts conserving the sugar supplies fo Continue reading >>