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Regulation Of Blood Glucose Level In Biochemistry

Regulation Of Blood Glucose Level In Diabetes Mellitus Using Palatable Diet Composition

Regulation Of Blood Glucose Level In Diabetes Mellitus Using Palatable Diet Composition

Abstract Diabetes mellitus results from the failure of the endocrine system to control the blood glucose levels within the normal limits. Normal people have fasting sugar level that generally run between 70–110 mg/dl, while a person is said to suffer from diabetes if the blood glucose level in the interval of 2 hours equals to or exceeds 180 mg/dl. It can be understood as a disorder of carbohydrate metabolism and characterized primarily by hyperglycemia and glycosuria with second anomalies of the metabolism of protein and fat. It is not only the leading cause of blindness, renal failure and non-traumatic amputations in adults but also a major cardiovascular risk factor in developing countries. So, it is of great interest to propose a palatable composition of quantitative diet for the human beings suffering from Diabetes Mellitus to regulate the blood glucose and insulin level. In the present study, the palatable composition is calculated by two mathematical models and given in the form of calories for protein (P), fat (F) and carbohydrate (C). For the calculations, the mixed population has been distinguished into three categories namely men, women and juvenile having various body frames i.e. small, medium and large. With the substitution of this composition in the solutions, the near- normal level of blood glucose and insulin is achieved. Hence, a plausible palatable composition of protein, fat and carbohydrate has been proposed which can be incorporated in diet for the significant regulation of blood glucose and insulin level in diabetic patients. Continue reading >>

Blood Glucose Regulation

Blood Glucose Regulation

Blood glucose regulation involves maintaining blood glucose levels at constant levels in the face of dynamic glucose intake and energy use by the body. Glucose, shown in figure 1 is key in the energy intake of humans. On average this target range is 60-100 mg/dL for an adult although people can be asymptomatic at much more varied levels. In order to maintain this range there are two main hormones that control blood glucose levels: insulin and glucagon. Insulin is released when there are high amounts of glucose in the blood stream. Glucagon is released when there are low levels of glucose in the blood stream. There are other hormones that effect glucose regulation and are mainly controlled by the sympathetic nervous system. Blood glucose regulation is very important to the maintenance of the human body. The brain doesn’t have any energy storage of its own and as a result needs a constant flow of glucose, using about 120 grams of glucose daily or about 60% of total glucose used by the body at resting state. [1] With out proper blood glucose regulation the brain and other organs could starve leading to death. Insulin A key regulatory pathway to control blood glucose levels is the hormone insulin. Insulin is released from the beta cells in the islets of Langerhans found in the pancreas. Insulin is released when there is a high concentration of glucose in the blood stream. The beta cells know to release insulin through the fallowing pathway depicted in figure 2. [2,3]Glucose enters the cell and ATP is produce in the mitochondria through the Krebs cycle and electron transport chain. This increase in ATP causes channels to closes. These channels allow potassium cations to flow into the cell. [2,3,]With these channels closed the inside of the cell becomes more negative causin Continue reading >>

Glucose Regulation Of Insulin Gene Expression In Pancreatic Β-cells

Glucose Regulation Of Insulin Gene Expression In Pancreatic Β-cells

Production and secretion of insulin from the β-cells of the pancreas is very crucial in maintaining normoglycaemia. This is achieved by tight regulation of insulin synthesis and exocytosis from the β-cells in response to changes in blood glucose levels. The synthesis of insulin is regulated by blood glucose levels at the transcriptional and post-transcriptional levels. Although many transcription factors have been implicated in the regulation of insulin gene transcription, three β-cell-specific transcriptional regulators, Pdx-1 (pancreatic and duodenal homeobox-1), NeuroD1 (neurogenic differentiation 1) and MafA (V-maf musculoaponeurotic fibrosarcoma oncogene homologue A), have been demonstrated to play a crucial role in glucose induction of insulin gene transcription and pancreatic β-cell function. These three transcription factors activate insulin gene expression in a co-ordinated and synergistic manner in response to increasing glucose levels. It has been shown that changes in glucose concentrations modulate the function of these β-cell transcription factors at multiple levels. These include changes in expression levels, subcellular localization, DNA-binding activity, transactivation capability and interaction with other proteins. Furthermore, all three transcription factors are able to induce insulin gene expression when expressed in non-β-cells, including liver and intestinal cells. The present review summarizes the recent findings on how glucose modulates the function of the β-cell transcription factors Pdx-1, NeuroD1 and MafA, and thereby tightly regulates insulin synthesis in accordance with blood glucose levels. Abbreviations: bHLH, basic helix–loop–helix; CAMKII, Ca2+/calmodulin-dependent protein kinase II; CBP, CREB (cAMP-response-element-binding p Continue reading >>

Biochemistry 07: Glucose Metabolism

Biochemistry 07: Glucose Metabolism

These are notes from lecture 7 of Harvard Extension’s biochemistry class. redox Redox is incredibly confusing because it’s reciprocal: things that oxidize are themselves reduced, and things that reduce are themselves oxidized. One molecule’s loss of an electron is another molecule’s gain. It’s like when people say “everybody is selling” such-and-such stock: no, actually, the number of sells and the number of buys are by definition always equal. A common mnemonic is OIL RIG – oxidation is losing (electrons), reduction is gaining (electrons). Here’s an attempt at an exhaustive description: A molecule is itself oxidized when it loses electrons, usually either by gaining oxygen or losing hydrogen. It by definition reduces something else. A molecule is itself reduced when it gains electrons, usually either by losing oxygen or gaining hydrogen. It by definition oxidizes something else. Here are several possible oxidation states of a one-carbon molecule. most reduced ← → most oxidized ΔG°oxidation (kJ/mol) -820 -703 -523 -285 0 Note that the more reduced it is, the more energy can be released by oxidizing it. Hence the thermodynamic favorability of burning methane for fuel to convert it to CO2. (technically the overall reaction is CH4 + 2 O2 → CO2 + 2 H2O and I think that the oxygen from O2 that becomes the water is technically what is being reduced). In biological systems, oxidation is usually synonymous with dehydrogenation and is performed by dehydrogenases, such as lactate dehydrogenase. Ways for electrons to be transferred include as H atoms (1 proton, one electron), or as :H- hydride ions (1 proton, 2 electrons). Adding a hydride ion reduces NADH to NAD+. NAD+ can then be oxidized to NADH. Fatty acid is more reduced than glucose. Fats are in a r Continue reading >>

Describe The Regulation Of Blood Glucose Level.

Describe The Regulation Of Blood Glucose Level.

The glucose level is regulated in pancreas by negative feedback loop, which means that when there is too much glucose, it is removed from the blood, and when there's too little, it is released into the blood. When there is too much glucose, beta cells in the islets in the pancreas are activated and produce hormone insulin. What insilin does is that it minds to receptors on muscles and liver and stimulate the uptake of glucose from blood. The uptaken glucose is then either used in cell respiration (muscles) or stored in a long-term form as a glycogen (liver). Thus the level of glucose decreases to the desired level. On the other hand, when the glucose level is too low, glucose needs to be replenished in the bloodstream. Low level glucose activates the alpha cells, which produce glucagon and release it into the blood. What glucagon does is that it stimulates breakdown of glycogen stored in the liver and converts it to glucose (reverse of what insulin does in liver). Glucose is released and the glucose level in the blood increases up to the required amount. Continue reading >>

Regulation Of Blood Glucose Level

Regulation Of Blood Glucose Level

Presentation on theme: "Regulation of Blood Glucose Level"— Presentation transcript: 2 INTRODUCTION Blood sugar concentration, or glucose level, refers to the amount of glucose present in the blood of a human. Normally, in mammals the blood glucose level is maintained at a reference range between about 3.6 and 5.8 mM (mmol/l). It is tightly regulated as a part of metabolic homeostasis. 3 INTRODUCTION….. 4 INTRODUCTION….. 6 Glucagon…. Glucagon binding to its' receptors on the surface of liver cells triggers an increase in cAMP production leading to an increased rate of glycogenolysis by activating glycogen phosphorylase via the PKA-mediated cascade. 7 The glucose enters extrahepatic cells where it is re-phosphorylated by hexokinase. 9 INSULIN 10 When blood glucose levels are low, the liver does not compete with other tissues for glucose since the extrahepatic uptake of glucose is stimulated in response to insulin. 11 Under conditions of high blood glucose, liver glucose levels will be high and the activity of glucokinase will be elevated. 12 Regulation of Glucose Metabolism During Exercise 13 Regulation of Glucose Metabolism During Exercise 15 1) Enhances gluconeogenesis; 2) Antagonizes Insulin. 1) Enhances entry of glucose into cells; 2) Enhances storage of glucose as glycogen, or conversion to fatty acids; 3) Enhances synthesis of fatty acids and proteins; 4) Suppresses breakdown of proteins into amino acids, of adipose tissue into free fatty acids. 16 Insulin Synthesis and Secretion 17 Biosynthesis of Insulin The insulin mRNA is translated as a single chain precursor called preproinsulin, and removal of its signal peptide during insertion into the endoplasmic reticulum generates proinsulin. 18 Proinsulin consists of three domains: an amino-terminal B chain, a Continue reading >>

General Paper Blood Glucose Regulation In An Intertidal Crab, Chasmagnathus Granulata (dana, 1851)

General Paper Blood Glucose Regulation In An Intertidal Crab, Chasmagnathus Granulata (dana, 1851)

Abstract 1. 1. Blood glucose regulation was investigated in an intertidal crab from south Brazil, Chasmagnathus granulata. 2. 2. There is no significant difference (P > 0.05) between blood glucose levels of males and females, ♂ ♀. 3. 3. There is no significant difference (P > 0.05) between blood glucose levels of normal and eyestalkless males until 96 hr after eyestalk ablation. 4. 4. There is a transitory but large increase in blood glucose levels of animals exposed to atmospheric air, the highest values being reached 1 hr after this exposure; 17.04 mg/100 ml. 5. 5. Handling and alien environment produce only a small increase in blood glucose levels of normal animals. 6. 6. There is a significant increase (P < 0.05) of crustacean hyperglycemie hormone (CHH) content in the eyestalks of animals exposed to atmospheric air for 1 hr, suggesting a higher rate of its synthesis during this period. 7. 7. Since the CHH seems to increase blood glucose by decreasing its utilization by the tissues and since there is a decrease in oxygen consumption in C. granulata exposed to atmospheric air, it is quite possible that this hormone is involved in the lack of the Pasteur effect, usually observed in facultative anaerobes. Continue reading >>

Blood Sugar Regulation

Blood Sugar Regulation

Most cells in the human body use the sugar called glucose as their major source of energy. Glucose molecules are broken down within cells in order to produce adenosine triphosphate (ATP) molecules, energy-rich molecules that power numerous cellular processes. Glucose molecules are delivered to cells by the circulating blood and therefore, to ensure a constant supply of glucose to cells, it is essential that blood glucose levels be maintained at relatively constant levels. Level constancy is accomplished primarily through negative feedback systems, which ensure that blood glucose concentration is maintained within the normal range of 70 to 110 milligrams (0.0024 to 0.0038 ounces) of glucose per deciliter (approximately one-fifth of a pint) of blood. Negative feedback systems are processes that sense changes in the body and activate mechanisms that reverse the changes in order to restore conditions to their normal levels. Negative feedback systems are critically important in homeostasis, the maintenance of relatively constant internal conditions. Disruptions in homeostasis lead to potentially life-threatening situations. The maintenance of relatively constant blood glucose levels is essential for the health of cells and thus the health of the entire body. Major factors that can increase blood glucose levels include glucose absorption by the small intestine (after ingesting a meal) and the production of new glucose molecules by liver cells. Major factors that can decrease blood glucose levels include the transport of glucose into cells (for use as a source of energy or to be stored for future use) and the loss of glucose in urine (an abnormal event that occurs in diabetes mellitus). Insulin and Glucagon In a healthy person, blood glucose levels are restored to normal level Continue reading >>

Introduction

Introduction

INTRODUCTION Glucose in the blood provides a source of fuel for all tissues of the body. Blood glucose levels are highest during the absorptive period after a meal, during which the stomach and small intestine are breaking down food and circulating glucose to the bloodstream. Blood glucose levels are the lowest during the postabsorptive period, when the stomach and small intestines are empty. Despite having food only periodically in the digestive tract, the body works to maintain relatively stable levels of circulatory glucose throughout the day. The body maintains blood glucose homeostasis mainly through the action of two hormones secreted by the pancreas. These hormones are insulin, which is released when glucose levels are high, and glucagon, which is released when glucose levels are low. The accompanying animation depicts the functions of these hormones in blood glucose regulation. CONCLUSION Throughout the day, the release of insulin and glucagon by the pancreas maintains relatively stable levels of glucose in the blood. During the absorptive period blood glucose levels tend to increase, and this increase stimulates the pancreas to release insulin into the bloodstream. Insulin promotes the uptake and utilization of glucose by most cells of the body. Thus, as long as the circulating glucose supply is high, cells preferentially use glucose as fuel and also use glucose to build energy storage molecules glycogen and fats. In the liver, insulin promotes conversion of glucose into glycogen and into fat. In muscle insulin promotes the use of glucose as fuel and its storage as glycogen. In fat cells insulin promotes the uptake of glucose and its conversion into fats. The nervous system does not require insulin to enable its cells to take up and utilize glucose. If glucose Continue reading >>

Regulation Of Glycolysis And Gluconeogenesis

Regulation Of Glycolysis And Gluconeogenesis

- [Instructor] At its most simplistic level, regulation of metabolic pathways inside of the body is really just a fancy word for a balancing act that's occurring in the body. So, to illustrate this, I have a seesaw and we've been learning about two metabolic pathways: glycolysis, which is the process of breaking down glucose into pyruvate; and gluconeogenesis, which is essentially the opposite in which we start out with pyruvate and through a little bit of a different route we end up back at glucose. And when we're talking about the regulation of these particular pathways, we're essentially asking ourself, "When is glycolysis the predominant pathway and when is gluconeogenesis the predominant pathway?" The body wants to make sure that we either have a net breakdown of glucose, in the case of glycolysis, or that we have a net production of glucose, in the case of gluconeogenesis. So now the next question is, "How does the body "accomplish this balancing act?" And to answer this question, the way I like to think about it is to think about it along a spectrum. There are very fast-acting forms of regulation that take place on the order of seconds, and there are very very slow forms of regulation that can take up to hours or even days to occur. So let's talk about each of these in a little bit more detail. The major principle that helps me understand fast-acting forms of regulation is a good old principle from general chemistry: Le Chatelier's Principle. So if you remember, Le Chatelier's Principle talks about anything that's in equilibrium and it says that if there's any change to this equilibrium, let's say more products are added or reactants are taken away, the equilibrium will adjust to essentially counter that change and return the system back to equilibrium. So what d Continue reading >>

Pancreatic Regulation Of Glucose Homeostasis

Pancreatic Regulation Of Glucose Homeostasis

Go to: The pancreas is an exocrine and endocrine organ The pancreas has key roles in the regulation of macronutrient digestion and hence metabolism/energy homeostasis by releasing various digestive enzymes and pancreatic hormones. It is located behind the stomach within the left upper abdominal cavity and is partitioned into head, body and tail. The majority of this secretory organ consists of acinar—or exocrine—cells that secrete the pancreatic juice containing digestive enzymes, such as amylase, pancreatic lipase and trypsinogen, into the ducts, that is, the main pancreatic and the accessory pancreatic duct. In contrast, pancreatic hormones are released in an endocrine manner, that is, direct secretion into the blood stream. The endocrine cells are clustered together, thereby forming the so-called islets of Langerhans, which are small, island-like structures within the exocrine pancreatic tissue that account for only 1–2% of the entire organ (Figure 1).1 There are five different cell types releasing various hormones from the endocrine system: glucagon-producing α-cells,2 which represent 15–20% of the total islet cells; amylin-, C-peptide- and insulin-producing β-cells,2 which account for 65–80% of the total cells; pancreatic polypeptide (PP)-producing γ-cells,3 which comprise 3–5% of the total islet cells; somatostatin-producing δ-cells,2 which constitute 3–10% of the total cells; and ghrelin-producing ɛ-cells,4 which comprise <1% of the total islet cells. Each of the hormones has distinct functions. Glucagon increases blood glucose levels, whereas insulin decreases them.5 Somatostatin inhibits both, glucagon and insulin release,6 whereas PP regulates the exocrine and endocrine secretion activity of the pancreas.3, 7 Altogether, these hormones regul Continue reading >>

Blood Glucose: Regulation And Renal Threshold

Blood Glucose: Regulation And Renal Threshold

ADVERTISEMENTS: In this article we will discuss about the Regulation and Renal Threshold for Blood Glucose. Regulation of the Blood Glucose: The stable blood glucose level is maintained by the role of liver, skeletal muscle, kidney, muscular exercise and hormones. Role of Liver: 1. Liver is the pivot of carbohydrate metabolism of the whole body. The presence of glucose-6-phosphatase in the liver converts glucose-6-phosphate to glucose which diffuses into the blood stream to form the constant and the only source of glucose of blood unless and until glucose is available from the intestine from carbohydrate diet. 2. Muscle glycogen cannot be converted to glucose due to the lack of the enzyme glucose-6-phosphatase. Therefore, glycogen is converted to lactic acid which by “Cori Cycle” or “Lactic Acid Cycle” is converted to glucose in the liver and the glucose is diffused to the blood stream. 3. The liver cells, like other cells, require the oxidation of organic substances to maintain their own vital functioning. In the absence of fuel glucose, glycogen is diminished and the oxidation of fat occurs forming keto acids. Some of the keto acids are utilized for cellular energy. But if the concentration of keto acids is increased, the keto acids diffuse into the blood stream and accumulate producing ketosis. 4. When the glycogen reservoir diminishes, the amino acids of the body proteins are utilized by the liver for gluconeogenesis. Role of Skeletal Muscle: 1. Extra-hepatic tissues are relatively impermeable to glucose and, therefore, insulin is required for the uptake of glucose to these cells. 2. Increased blood glucose promotes glycogenesis and oxidation of glucose in muscles. Muscle glycogen does not serve directly as a source of glucose during hypoglycemia. But glucos Continue reading >>

Normal Regulation Of Blood Glucose

Normal Regulation Of Blood Glucose

The human body wants blood glucose (blood sugar) maintained in a very narrow range. Insulin and glucagon are the hormones which make this happen. Both insulin and glucagon are secreted from the pancreas, and thus are referred to as pancreatic endocrine hormones. The picture on the left shows the intimate relationship both insulin and glucagon have to each other. Note that the pancreas serves as the central player in this scheme. It is the production of insulin and glucagon by the pancreas which ultimately determines if a patient has diabetes, hypoglycemia, or some other sugar problem. In this Article Insulin Basics: How Insulin Helps Control Blood Glucose Levels Insulin and glucagon are hormones secreted by islet cells within the pancreas. They are both secreted in response to blood sugar levels, but in opposite fashion! Insulin is normally secreted by the beta cells (a type of islet cell) of the pancreas. The stimulus for insulin secretion is a HIGH blood glucose...it's as simple as that! Although there is always a low level of insulin secreted by the pancreas, the amount secreted into the blood increases as the blood glucose rises. Similarly, as blood glucose falls, the amount of insulin secreted by the pancreatic islets goes down. As can be seen in the picture, insulin has an effect on a number of cells, including muscle, red blood cells, and fat cells. In response to insulin, these cells absorb glucose out of the blood, having the net effect of lowering the high blood glucose levels into the normal range. Glucagon is secreted by the alpha cells of the pancreatic islets in much the same manner as insulin...except in the opposite direction. If blood glucose is high, then no glucagon is secreted. When blood glucose goes LOW, however, (such as between meals, and during Continue reading >>

Carbohydrates, Proteins, Fats, And Blood Sugar

Carbohydrates, Proteins, Fats, And Blood Sugar

The body uses three main nutrients to function-carbohydrate, protein, and fat. These nutrients are digested into simpler compounds. Carbohydrates are used for energy (glucose). Fats are used for energy after they are broken into fatty acids. Protein can also be used for energy, but the first job is to help with making hormones, muscle, and other proteins. Nutrients needed by the body and what they are used for Type of nutrient Where it is found How it is used Carbohydrate (starches and sugars) Breads Grains Fruits Vegetables Milk and yogurt Foods with sugar Broken down into glucose, used to supply energy to cells. Extra is stored in the liver. Protein Meat Seafood Legumes Nuts and seeds Eggs Milk products Vegetables Broken down into amino acids, used to build muscle and to make other proteins that are essential for the body to function. ADVERTISINGinRead invented by Teads Fat Oils Butter Egg yolks Animal products Broken down into fatty acids to make cell linings and hormones. Extra is stored in fat cells. After a meal, the blood sugar (glucose) level rises as carbohydrate is digested. This signals the beta cells of the pancreas to release insulin into the bloodstream. Insulin helps glucose enter the body's cells to be used for energy. If all the glucose is not needed for energy, some of it is stored in fat cells and in the liver as glycogen. As sugar moves from the blood to the cells, the blood glucose level returns to a normal between-meal range. Several hormones and processes help regulate the blood sugar level and keep it within a certain range (70 mg/dL to 120 mg/dL). When the blood sugar level falls below that range, which may happen between meals, the body has at least three ways of reacting: Cells in the pancreas can release glucagon, a hormone that signals the b Continue reading >>

Regulation Of Blood Glucose Levels

Regulation Of Blood Glucose Levels

1. Glucose Homeostasis ??? It is the maintenance of blood glucose level within the normal range. The blood glucose level must be maintained within the narrow limits of 70-100 mg/dl. 2. Normal blood glucose level (fasting) is 70-110mg/dl Post-prandial blood glucose level is 120-140mg/dl. Above and below the above level is consider as abnormal. Hyperglycemia - Levels above the normal range Hypoglycemia - Levels below the normal range 3. mostly Lipogenesis Diet after digestion and absorption Glycogenolysis (Liver glycogen) Gluconeogenesis (mainly from AAs) Blood Glucose 70-110mg/dl Main source during prolonged starvation (>18 hrs) Source during early fasting (12-18hrs) Oxidation glycogenesis ConversionUse Storage 4. Homeostasis of blood glucose Low blood glucose High blood glucose Beta cells release insulin Alpha cells release glucagon Normal blood glucose Glycogenolysis in the liver; Glucose released to blood Peripheral tissue Cells take glucose From blood 5. Factors involving in the homeostasis of blood glucose Metabolic process Hormones Renal mechanism 6. Fundamental Regulatory Mechanisms 1. As blood sugar tends to increase Secretion of insulin, Glycogenesis is accelerated  Utilisation of glucose by tissues is increased 2. As blood sugar tends to decrease  secretion of insulin,  ratio of insulin/glucocorticoids and GH  production of glucose mainly by gluconeogenesis & glycogenolysis  Utilisation of glucose by tissues 7. Blood glucose regulation during Well-fed state Glucose Glucose Glycogen Pyruvate Fat Lactate Insulin GIT Portal vein Adipose tissue Muscle Brain Glucose CO2 + H2O Fat Glucose CO2 + H2O 8. Blood glucose regulation during Post-prandial state Glucose Glycogen Lactate Lactate Glucagon GIT Portal vein M Continue reading >>

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