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# Glycerol To Glucose

## Cory Cycle , Glucose-alanine Cycle And Glycerol-glucose Cycle

... cortisol, growth hormone, thyreoid hormones (T3 and T4) and many others. The proper functions of these hormones is precise control of glucose concentration in the blood. Insulin and glucagon are two major hormones involved in regulation of blood glucose level. They are both secreted in response to blood sugar levels, but in opposite fashion. At the same time, enhanced insulin secretion induced increased glucagon secretion. Insulin has a hypoglycemic effect. Secretion of insulin is a response to increased glucose level in the blood. In addition to the direct effects of hyperglycemia in enhancing the uptake of glucose into both the liver and peripheral tissues, the hormon insulin plays a central role in the regulation of the blood glucose concentration. Similarly, as blood glucose falls, the amount of insulin secreted by the pancreatic islets goes down. Glucagon, as a direct antagonist of insulin, has a hyperglycemic effect. Secretion of glucagon is a response to decreased glucose level in the blood (Chattoraj & Watts,1986; Ginsberg, 1990 a, 1990b; Mayes,1975; King, 2011). Insulin is a small protein consisting of an alpha chain of 21 amino acids linked by two disulfide (SS) bridges to a beta chain of 30 amino acids. The precursor of insulin is a proinsulin, which contains C peptide (conective peptide). The conversion of proinsulin to insulin requires biologic proteolysis (Ginsberg,1990; Bowen, 2010; Harper, 1975; Chattoraj & Watts,1986). The stimulus for insulin secretion is a high blood glucose. Insulin is produced by cells of Langerhans islets in pancreas and is secreted into the blood as a direct response to hyperglycemuia. Beta cells have channels in their plasma membrane that serve as glucose detectors. When blood glucose levels rise (after a meal), insulin is s Continue reading >>

## Glycerol Production From Glucose And Fructose By 3t3-l1 Cells: A Mechanism Of Adipocyte Defense From Excess Substrate

Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Glycerol Production from Glucose and Fructose by 3T3-L1 Cells: A Mechanism of Adipocyte Defense from Excess Substrate Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Affiliation Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Continue reading >>

## Gluconeogenesis: Endogenous Glucose Synthesis

Reactions of Gluconeogenesis: Gluconeogenesis from two moles of pyruvate to two moles of 1,3-bisphosphoglycerate consumes six moles of ATP. This makes the process of gluconeogenesis very costly from an energy standpoint considering that glucose oxidation to two moles of pyruvate yields two moles of ATP. The major hepatic substrates for gluconeogenesis (glycerol, lactate, alanine, and pyruvate) are enclosed in red boxes for highlighting. The reactions that take place in the mitochondria are pyruvate to OAA and OAA to malate. Pyruvate from the cytosol is transported across the inner mitochondrial membrane by the pyruvate transporter. Transport of pyruvate across the plasma membrane is catalyzed by the SLC16A1 protein (also called the monocarboxylic acid transporter 1, MCT1) and transport across the outer mitochondrial membrane involves a voltage-dependent porin transporter. Transport across the inner mitochondrial membrane requires a heterotetrameric transport complex (mitochondrial pyruvate carrier) consisting of the MPC1 gene and MPC2 gene encoded proteins. Following reduction of OAA to malate the malate is transported to the cytosol by the malate transporter (SLC25A11). In the cytosol the malate is oxidized to OAA and the OOA then feeds into the gluconeogenic pathway via conversion to PEP via PEPCK. The PEPCK reaction is another site for consumption of an ATP equivalent (GTP is utilized in the PEPCK reaction). The reversal of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) reaction requires a supply of NADH. When lactate is the gluconeogenic substrate the NADH is supplied by the lactate dehydrogenase (LDH) reaction (indicated by the dashes lines), and it is supplied by the malate dehydrogenase reaction when pyruvate and alanine are the substrates. Secondly, one mo Continue reading >>

## Glycerol Diffusion In Skin At Glucose Impact On Tissue

Glycerol diffusion in skin at glucose impact on tissue Abstract: In this paper we present results of experimental study of glucose impact on skin tissue by testing tissue structure alteration at glycerol diffusivity. The measurements have been performed using Ocean Optics spectrometer USB4000 in transmittance mode. In the in vitro experiments twenty samples of intact rat skin were used. Transmittance of ten samples was measured immediately after obtaining the samples concurrently with administration of 58% aqueous glycerol solution in the spectral range 400-1000 nm. The second group of the rat skin samples (ten samples) was incubated during 24 hours in 40%-glucose solution and during 24 hours in physiological solution. After that transmittance of the ten samples was measured concurrently with administration of the 58%- glycerol solution. Special computer program has been developed for processing of the experimental data and estimation of the glycerol diffusion rate. Degree of optical clearing of intact skin samples and skin samples previously immersed in glucose solution were estimated and compared. As a result we found that the optical clearing of intact skin increases about 3 times faster in comparison with skin immersed in the glucose solution. Continue reading >>

## Glycerol Is Synthesized And Secreted By Adipocytes To Dispose Of Excess Glucose, Via Glycerogenesis And Increased Acyl-glycerol Turnover

Article | Open Glycerol is synthesized and secreted by adipocytes to dispose of excess glucose, via glycerogenesis and increased acyl-glycerol turnover Scientific Reportsvolume7, Articlenumber:8983 (2017) White adipose tissue (WAT) produces large amounts of lactate and glycerol from glucose. We used mature epididymal adipocytes to analyse the relative importance of glycolytic versus lipogenic glycerol in adipocytes devoid of external stimuli. Cells were incubated (24/48 h) with 7/14 mM glucose; half of the wells contained 14C-glucose. We analysed glucose label fate, medium metabolites, and the expression of key genes coding for proteins controlling glycerol metabolism. The effects of initial glucose levels were small, but time of incubation increased cell activity and modified its metabolic focus. The massive efflux of lactate was uniform with time and unrelated to glucose concentration; however, glycerol-3P synthesis was higher in the second day of incubation, being largely incorporated into the glycerides-glycerol fraction. Glycerophosphatase expression was not affected by incubation. The stimulation of glycerogenic enzymes expression was mirrored in lipases. The result was a shift from medium glycolytic to lipolytic glycerol released as a consequence of increased triacylglycerol turnover, in which most fatty acids were recycled. Production of glycerol seems to be an important primary function of adipocytes, maintained both by glycerogenesis and acyl-glycerol turnover. Production of 3C fragments may also contribute to convert excess glucose into smaller, more readily usable, 3C metabolites. Intact white adipose tissue (WAT) (and isolated adipocytes) secrete significant amounts of glycerol 1 . It has been long assumed that this glycerol is a by-product of lipolysis, r Continue reading >>

## Glucose-to-glycerol Conversion In Long-lived Yeast Provides Anti-aging Effects

Cell biologists have found a more filling substitute for caloric restriction in extending the life span of simple organisms. Researchers show that yeast cells maintained on a glycerol diet live twice as long as normal -- as long as yeast cells on a severe caloric-restriction diet. They are also more resistant to cell damage. Cell biologists have found a more filling substitute for caloric restriction in extending the life span of simple organisms. In a study published May 8 in the open-access journal PLoS Genetics, researchers from the University of Southern California Andrus Gerontology Center show that yeast cells maintained on a glycerol diet live twice as long as normal -- as long as yeast cells on a severe caloric-restriction diet. They are also more resistant to cell damage. Many studies have shown that caloric restriction can extend the life span of a variety of laboratory animals. Caloric restriction is also known to cause major improvements in a number of markers for cardiovascular diseases in humans. This study is the first to propose that "dietary substitution" can replace "dietary restriction" in a living species. "If you add glycerol, or restrict caloric intake, you obtain the same effect," said senior author Valter Longo. "It's as good as calorie restriction, yet cells can take it up and utilize it to generate energy or for the synthesis of cellular components." Longo and colleagues Min Wei and Paola Fabrizio introduced a glycerol diet after discovering that genetically engineered long-lived yeast cells that survive up to 5-fold longer than normal have increased levels of the genes that produce glycerol. In fact, they convert virtually all the glucose and ethanol into glycerol. Notably, these cells have a reduced activity in the TOR1/SCH9 pathway, which i Continue reading >>

## Assessment Of Bio-hydrogen Production From Glycerol And Glucose By Fermentative Bacteria | Dimanta | Energetika

Assessment of bio-hydrogen production from glycerol and glucose by fermentative bacteria I. Dimanta, V. Nikolajeva, A. Gruduls, I. Muinieks, J. Kleperis Microorganisms are capable to produce hydrogen during fermentation of organic substrates and industrial waste products can be used as feedstock for hydrogen producing bacteria. One of the substrates that can be effectively used for microbial hydrogen production is glycerol, which is a by-product from the process of biodiesel production, but glucose is mainly used as a model substrate. Different bacterial isolates were tested for hydrogen gas production rates from glucose and glycerol with test-systems constructed in our laboratory. Test-systems were optimised to allow adequate substrate and bacterial strain hydrogen productivity estimation in the liquid and gaseous phases. It was concluded that several of the isolated bacterial strains are suitable for bio-hydrogen production using glycerol as a substrate. Assessment was developed to establish whether microbial conversion of glycerol is an economically and environmentally viable possibility for bio-hydrogen production. The raw material cost noticeably decreases because of large quantities of available crude glycerol after biodiesel production and the highly reduced nature of carbon in glycerol perse. Continue reading >>

## Glyceroneogenesis And The Source Of Glycerol For Hepatic Triacylglycerol Synthesis In Humans*

[2H]water, 99.9%2H, and [1,2,3-13C3]glycerol, 99% 13C, were obtained from Isotech, Inc. (Miamisburg, OH). The respective contributions of plasma glycerol and pyruvate were quantified in two separate groups of nonpregnant and pregnant women. Written informed consent was obtained from each woman and her spouse (when available) after fully explaining the procedure. The protocol was approved by the Institutional Review Board of the University Hospitals of Cleveland. Glycerol Incorporation in Triacylglycerol [1,2,3-13C]Glycerol (over 99%13C) was infused in five normal nonpregnant women after an overnight fast. They were physically healthy and had a negative history of diabetes or other metabolic disorders in their family. The tracer glycerol was dissolved in normal saline, sterilized by Millipore filtration, and tested for pyrogenicity and sterility. All subjects reported to the Clinical Research Center at University of Hospitals of Cleveland following a 12-h fast. The tracer was infused at a constant rate of 0.03 mg/kg of body weight/min for a period of 5 h, following a priming dose of 0.5 mg/kg. Arterialized blood samples were obtained in heparinized syringes from the opposite arm at 30-min intervals starting at 1 h. Blood samples were centrifuged immediately, and the plasma samples were stored at 70 C until analysis. Pyruvate Incorporation into Triacylglycerol The contribution of pyruvate to glycerol in triacylglycerol was evaluated using the total body water labeling method described for determining the rate of gluconeogenesis in vivo ( 12 , 13 ). The volunteers had been studied previously, and the details of the experimental design and the data on glucose turnover and gluconeogenesis have been reported previously ( 12 ). Plasma samples for the quantification of glycero Continue reading >>

## Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Ischemic stroke and neonatal hypoxic-ischemic encephalopathy are two of the leading causes of disability in adults and infants. The energy demands of the brain are provided by mitochondrial oxidative phosphorylation. Ischemia/reperfusion (I/R) affects the production of ATP in brain mitochondria, leading to energy failure and death of the affected tissue. Among the enzymes of the mitochondrial respiratory chain, mitochondrial complex I is the most sensitive to I/R; however, the mechanisms of its inhibition are poorly understood. This article reviews some of the existing data on the mitochondria impairment during I/R and proposes two distinct mechanisms of complex I damage emerging from recent studies. One mechanism is a reversible dissociation of natural flavin mononucleotide cofactor from the enzyme I after ischemia. Another mechanism is a modification of critical cysteine residue of complex I involved into the active/deactive conformational transition of the enzyme. I describe potential effects of these two processes in the development of mitochondrial I/R injury and briefly discuss possible neuroprotective strategies to ameliorate I/R brain injury. Reactive oxygen species (ROS) are byproducts of physiological mitochondrial metabolism that are involved in several cellular signaling pathways as well as tissue injury and pathophysiological processes, including brain ischemiareperfusion injury. The mitochondrial respiratory chain is considered a major source of ROS; however, there is little agreement on how ROS release depends on oxygen concentration.The rate of H2O2 release by intact brain mitochondria was measured with an Amplex UltraRed assay using a highresolution respirometer (Oroboros) equipped with a fluorescent optical module and a system of controlled gas flow f Continue reading >>

## Fat To Glycerol To Glucose

Fat to Glycerol to Glucose , 08-26-2009 11:18 PM ! ! ! I have been pursuing a low card woe for 8 months and have maintained the same weight basically since just after the first 2 weeks. Maintain carbs at 20 grams per day. Getting desperate. Got the book The metabolism Miracle by Diane Kress. She says basically that you body will use dietary fat for energy before it will use it's own fat stores. I'm confused. So I have done some reading online. Learning that dietary fat is turned into glycerol and then turned into glucose. So this tells me that dietary fat should be carefully controlled or at the very least you won't lose weight. I know there are some really smart people on this discussion board and I would really appreciate any information you can share. RE: Fat to Glycerol to Glucose , 08-27-2009 10:23 AM I'm confused. So I have done some reading online. Learning that dietary fat is turned into glycerol and then turned into glucose. So this tells me that dietary fat should be carefully controlled or at the very least you won't lose weight. I know there are some really smart people on this discussion board and I would really appreciate any information you can share. Your body's main energy "currency" is glucose. Even if you never ingested a carb, your body makes its own glucose, and if your BG gets much below 70 you'll feel the symptoms of low BG (shaky, weak, etc.) Fats (ingested and stored) are triglycerides. Glycerol is the small backbone connecting 3 fatty acids. Our bodies use the fatty acids for energy by oxidizing them (serially lopping off carbon fragments to form acyl CoA). For every gram of fat, the glycerol is a teeeeeeeeeny part -- kind of like the an artificial sweetener amount of grams if that makes any sense. I would not worry at all about regulating fat Continue reading >>

## Jci -interstitial Fluid Concentrations Of Glycerol, Glucose, And Amino Acids In Human Quadricep Muscle And Adipose Tissue. Evidence For Significant Lipolysis In Skeletal Muscle.

Interstitial fluid concentrations of glycerol, glucose, and amino acids in human quadricep muscle and adipose tissue. Evidence for significant lipolysis in skeletal muscle. D G Maggs, , W V Tamborlane, R S Sherwin J Clin Invest. 1995; 96(1) :370-377. . To determine the relationship between circulating metabolic fuels and their local concentrations in peripheral tissues we measured glycerol, glucose, and amino acids by microdialysis in muscle and adipose interstitium of 10 fasted, nonobese human subjects during (a) baseline, (b) euglycemic hyperinsulinemia (3 mU/kg per min for 3 h) and, (c) local norepinephrine reuptake blockade (NOR). At baseline, interstitial glycerol was strikingly higher (P < 0.0001) in muscle (3710 microM) and adipose tissue (2760 microM) compared with plasma (87 microM), whereas interstitial glucose (muscle 3.3, fat 3.6 mM) was lower (P < 0.01) than plasma levels (4.8 mM). Taurine, glutamine, and alanine levels were higher in muscle than in adipose or plasma (P < 0.05). Euglycemic hyperinsulinemia did not affect interstitial glucose, but induced a fall in plasma glycerol and amino acids paralleled by similar changes in the interstitium of both tissues. Local NOR provoked a fivefold increase in glycerol (P < 0.001) and twofold increase in norepinephrine (P < 0.01) in both muscle and adipose tissues. To conclude, interstitial substrate levels in human skeletal muscle and adipose tissue differ substantially from those in the circulation and this disparity is most pronounced for glycerol which is raised in muscle as well as adipose tissue. In muscle, insulin suppressed and NOR increased interstitial glycerol concentrations. Our data suggest unexpectedly high rates of [] Continue reading >>

## Comparison Of Glucose, Glycerol And Crude Glycerol Fermentation By Escherichia Coli K12

The ability of E. coli to transform crude glycerol, waste of biodiesel production, into ethanol will allow for a zero waste process stream, leading to an increase in the economic viability of biofuels industry. The main aspect of this investigation is to study and compare the use of glucose, glycerol and crude glycerol as a carbon source for anaerobic growth of E. coli in order to produce ethanol and H2. The comparison was carried out in two separate experiments. For glycerol and glucose, the effect of carbon source is investigated by a comparative growth analysis of E. coli in the two substrates under anaerobic conditions. For glycerol and crude glycerol, the effects of initial glycerol concentration, supplement concentration and agitation speed on final ethanol concentration and dry weight were tested. E. coli MG1655 (ATCC 700926) was obtained from Cedar Lane Labs. M9 minimal medium containing 990 ml distilled water, 2 ml of MgSO4, 10 ml of 20% glucose, 6.0 g Na2HPO4, 3.0 g KH2PO4, 0.5 g NaCl and 1.0 g NH4Cl was mixed; 3.6 g of agar was added to 240 ml of this medium, autoclaved and poured into petri dishes. 60 ml of the medium was used to rehydrate the bacteria pellet. The bacteria was then transferred to the prepared plates and grown overnight at 37C. Single colonies were then transplanted onto Luria Bertani agar plates and incubated overnight at 37C. Single colonies selected from these agar plates were used to generate 80% glycerol stock solutions which were then stored at 80C. The innoculum for experiments was prepared in hungate tubes (Bellco Glass, 2047-16125) filled with MOPS minimal media [ 9 ] supplemented with 1% 1.32 mMN2HPO4 and 0.1% 1 mol sodium selenite. The amount of 10% glycerol was added as carbon source and the pH adjusted to 6.3 with 1 M NaOH. Bact Continue reading >>

## Comparison Of The Effects Of Pre-exercise Feeding Of Glucose, Glycerol And Placebo On Endurance And Fuel Homeostasis In Man

Comparison of the effects of pre-exercise feeding of glucose, glycerol and placebo on endurance and fuel homeostasis in man Six men were studied during exercise to exhaustion on a cycle ergometer at 73% of $$\dot V_{O_{2max} }$$ following ingestion of glycerol, glucose or placebo. Five of the subjects exercised for longer on the glucose trial compared to the placebo trial (p<0.1; 108.8 vs 95.9 min). Exercise time to exhaustion on the glucose trial was longer (p<0.01) than on the glycerol trial (86.0 min). No difference in performance was found between the glycerol and placebo trials. The ingestion of glucose (lg kg1 body weight) 45 min before exercise produced a 50% rise in blood glucose and a 3-fold rise in plasma insulin at zero min of exercise. Total carbohydrate oxidation was increased by 26% compared to placebo and none of the subjects exhibited a fall in blood glucose below 4 mmol l1 during the exercise. The ingestion of glycerol (lg kg1 body weight) 45 min before exercise produced a 340-fold increase in blood glycerol concentration at zero min of exercise, but did not affect resting blood glucose or plasma insulin levels; blood glucose levels were up to 14% higher (p<0.05) in the later stages of exercise and at exhaustion compared to the placebo or glucose trials. Both glycerol and glucose feedings lowered the magnitude of the rise in plasma FFA during exercise compared to placebo. Levels of blood lactate and alanine during exercise were not different on the 3 dietary treatments. These data contrast with previous reports that have indicated glucose feeding pre-exercise produces hypoglycaemia during strenuous submaximal exercise and reduces endurance performance. It appears that man cannot use glycerol as a gluconeogenic substrate rapidly enough to serve as a ma Continue reading >>

## Diabetes Enhances The Palatability Of Glycerol And Glucose

Volume 29, Issue 3 , September 1982, Pages 561-566 Diabetes enhances the palatability of glycerol and glucose Author links open overlay panel Deborah J.Brief John D.Davis Get rights and content Male rats were provided with flavored solutions (0.3 M glucose, 0.3 M glycerol or 0.6 M glycerol) or water before and after the induction of diabetes by streptozotocin. Normal animals given 0.3 M glucose showed a significant increase in fluid intake but normal animals offered the glycerol solutions did not show an increase in intake compared to animals given water. After the onset of diabetes, exposure to the same flavored solutions resulted in significant increases in fluid intake by animals offered both the glycerol and glucose solutions. The animals offered glucose consumed significantly more than did the animals offered the glycerol solutions. The animals offered 0.6 M glycerol consumed significantly more than did the animals offered 0.3 M glycerol on 8 out of the 10 days of exposure. Therefore, while diabetes does not appear to modify the palatability of glucose it seems to produce an enhanced palatability for glycerol not seen in normal rats. Continue reading >>

## Gluconeogenesis

Not to be confused with Glycogenesis or Glyceroneogenesis. Simplified Gluconeogenesis Pathway Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. From breakdown of proteins, these substrates include glucogenic amino acids (although not ketogenic amino acids); from breakdown of lipids (such as triglycerides), they include glycerol (although not fatty acids); and from other steps in metabolism they include pyruvate and lactate. Gluconeogenesis is one of several main mechanisms used by humans and many other animals to maintain blood glucose levels, avoiding low levels (hypoglycemia). Other means include the degradation of glycogen (glycogenolysis)[1] and fatty acid catabolism. Gluconeogenesis is a ubiquitous process, present in plants, animals, fungi, bacteria, and other microorganisms.[2] In vertebrates, gluconeogenesis takes place mainly in the liver and, to a lesser extent, in the cortex of the kidneys. In ruminants, this tends to be a continuous process.[3] In many other animals, the process occurs during periods of fasting, starvation, low-carbohydrate diets, or intense exercise. The process is highly endergonic until it is coupled to the hydrolysis of ATP or GTP, effectively making the process exergonic. For example, the pathway leading from pyruvate to glucose-6-phosphate requires 4 molecules of ATP and 2 molecules of GTP to proceed spontaneously. Gluconeogenesis is often associated with ketosis. Gluconeogenesis is also a target of therapy for type 2 diabetes, such as the antidiabetic drug, metformin, which inhibits glucose formation and stimulates glucose uptake by cells.[4] In ruminants, because dietary carbohydrates tend to be metabolized by rumen organisms, gluconeogenesis occurs Continue reading >>