Mannitol is a type of sugar alcohol, used as a medication. As a sugar, it is used as a sweetener in diabetic food, as it is poorly absorbed from the intestines; as a medication, it is used to decrease pressure in the eyes, as in glaucoma, to lower increased intracranial pressure. Medically, it is given by injection. Effects begin within 15 minutes and last up to 8 hours. Common side effects from medical use include electrolyte dehydration. Other serious side effects may include kidney problems, it is unclear. Mannitol is in the osmotic diuretic family of medications and works by pulling fluid from the brain and eyes; the discovery of mannitol is attributed to Joseph Louis Proust in 1806. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system; the wholesale cost in the developing world is about US$1.12 to 5.80 a dose. In the United States, a course of treatment costs $25 to 50, it was made from the flowering ash and called manna due to its supposed resemblance to the Biblical food.
Mannitol is on the World Anti-Doping Agency's banned drug list due to concerns that it may mask other drugs. Mannitol is used to reduce acutely raised intracranial pressure until more definitive treatment can be applied, e.g. after head trauma. It may be used for certain cases of kidney failure with low urine output, decreasing pressure in the eye, to increase the elimination of certain toxins, to treat fluid build up. Intraoperative mannitol prior to vessel clamp release during renal transplant has been shown to reduce post-transplant kidney injury, but has not been shown to reduce graft rejection. Mannitol acts as an osmotic laxative in oral doses larger than 20 g, is sometimes sold as a laxative for children.. The use of mannitol, when inhaled, as a bronchial irritant as an alternative method of diagnosis of exercise-induced asthma has been proposed. A 2013 systematic review concluded evidence to support its use for this purpose at this time is insufficient. Mannitol is used in the circuit prime of a heart lung machine during cardiopulmonary bypass.
The presence of mannitol preserves renal function during the times of low blood flow and pressure, while the patient is on bypass. The solution prevents the swelling of endothelial cells in the kidney, which may have otherwise reduced blood flow to this area and resulted in cell damage. Mannitol can be used to temporarily encapsulate a sharp object while it is passed through the venous system; because the mannitol dissolves in blood, the sharp point will become exposed at its destination. Mannitol is the first drug of choice for the treatment of acute glaucoma in veterinary medicine, it is administered as a 20% solution intravenously. It dehydrates the vitreous humor and, lowers the intraocular pressure. However, it requires an intact blood-ocular barrier to work. Mannitol increases blood glucose to a lesser extent than sucrose so is used as a sweetener for people with diabetes, in chewing gums. Although mannitol has a higher heat of solution than most sugar alcohols, its comparatively low solubility reduces the cooling effect found in mint candies and gums.
However, when mannitol is dissolved in a product, it induces a strong cooling effect. It has a low hygroscopicity – it does not pick up water from the air until the humidity level is 98%; this makes mannitol useful as a coating for hard candies, dried fruits, chewing gums, it is included as an ingredient in candies and chewing gum. The pleasant taste and mouthfeel of mannitol makes it a popular excipient for chewable tablets. Mannitol can be used to form a complex with boric acid; this increases the acid strength of the boric acid, permitting better precision in volumetric analysis of this acid. Mannitol is the primary ingredient of mannitol salt agar, a bacterial growth medium, is used in others. Mannitol is used as a cutting agent in various drugs, such as cocaine. A mixture of mannitol and fentanyl in ratio 1:10 is labeled and sold as "China white", a popular heroin substitute. Mannitol is contraindicated in people with anuria, congestive heart failure, active cerebral haemorrhage. Adverse effects include volume depletion leading to metabolic acidosis.
Mannitol is an isomer of another sugar alcohol. While similar, the two sugar alcohols have different sources in nature, melting points, uses. Mannitol is classified as a sugar alcohol. Other sugar alcohols include sorbitol. Mannitol and sorbitol are isomers, the only difference being the orientation of the hydroxyl group on carbon 2. Mannitol is produced via the hydrogenation of fructose, formed from either starch or sucrose. Although starch is a cheaper source than sucrose, the transformation of starch is much more complicated, it yields a syrup containing about 42% fructose, 52% glucose, 6% maltose. Sucrose is hydrolyzed into an invert sugar syrup, which contains about 50% fructose. In both cases, the syrups are chromatographically purified to contain 90–95% fructose; the fructose is hydrogenated over a nickel catalyst into a mixture of isomers sorbitol and mannitol. Yield is 50%:50%, although alkaline reaction conditions can increase mannitol yields. Mannitol is one of the most abundant ene
Myoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in all mammals. It is distantly related to hemoglobin, the iron- and oxygen-binding protein in blood in the red blood cells. In humans, myoglobin is only found in the bloodstream after muscle injury, it is an abnormal finding, can be diagnostically relevant when found in blood. Myoglobin is the primary oxygen-carrying pigment of muscle tissues. High concentrations of myoglobin in muscle cells allow organisms to hold their breath for a longer period of time. Diving mammals such as whales and seals have muscles with high abundance of myoglobin. Myoglobin is found in Type I muscle, Type II A and Type II B, but most texts consider myoglobin not to be found in smooth muscle. Myoglobin was the first protein to have its three-dimensional structure revealed by X-ray crystallography; this achievement was reported in 1958 by associates. For this discovery, John Kendrew shared the 1962 Nobel Prize in chemistry with Max Perutz.
Despite being one of the most studied proteins in biology, its physiological function is not yet conclusively established: mice genetically engineered to lack myoglobin can be viable and fertile but show many cellular and physiological adaptations to overcome the loss. Through observing these changes in myoglobin-deplete mice, it is hypothesised that myoglobin function relates to increased oxygen transport to muscle, oxygen storage and as a scavenger of reactive oxygen species. In humans myoglobin is encoded by the MB gene. Myoglobin can take the forms oxymyoglobin and metmyoglobin, analogously to hemoglobin taking the forms oxyhemoglobin, carboxyhemoglobin, methemoglobin. Like hemoglobin, myoglobin is a cytoplasmic protein, it harbors only one heme group. Although its heme group is identical to those in Hb, Mb has a higher affinity for oxygen than does hemoglobin; this difference is related to its different role: whereas hemoglobin transports oxygen, myoglobin's function is to store oxygen. Myoglobin contains hemes, pigments responsible for the colour of red meat.
The colour that meat takes is determined by the degree of oxidation of the myoglobin. In fresh meat the iron atom is in the ferrous oxidation state bound to an oxygen molecule. Meat cooked well done is brown because the iron atom is now in the ferric oxidation state, having lost an electron. If meat has been exposed to nitrites, it will remain pink because the iron atom is bound to NO, nitric oxide. Grilled meats can take on a pink "smoke ring" that comes from the iron binding to a molecule of carbon monoxide. Raw meat packed in a carbon monoxide atmosphere shows this same pink "smoke ring" due to the same principles. Notably, the surface of this raw meat displays the pink color, associated in consumers' minds with fresh meat; this artificially induced pink color can persist up to one year. Hormel and Cargill are both reported to use this meat-packing process, meat treated this way has been in the consumer market since 2003. Myoglobin is released from damaged muscle tissue, which has high concentrations of myoglobin.
The released myoglobin is filtered by the kidneys but is toxic to the renal tubular epithelium and so may cause acute kidney injury. It is not the myoglobin itself, toxic but the ferrihemate portion, dissociated from myoglobin in acidic environments. Myoglobin is a sensitive marker for muscle injury, making it a potential marker for heart attack in patients with chest pain. However, elevated myoglobin has low specificity for acute myocardial infarction and thus CK-MB, cardiac Troponin, ECG, clinical signs should be taken into account to make the diagnosis. Myoglobin belongs to the globin superfamily of proteins, as with other globins, consists of eight alpha helices connected by loops. Myoglobin contains 154 amino acids. Myoglobin contains a porphyrin ring with an iron at its center. A proximal histidine group is attached directly to iron, a distal histidine group hovers near the opposite face; the distal imidazole is not bonded to the iron but is available to interact with the substrate O2. This interaction encourages the binding of O2, but not carbon monoxide, which still binds about 240× more than O2.
The binding of O2 causes substantial structural change at the Fe center, which shrinks in radius and moves into the center of N4 pocket. O2-binding induces "spin-pairing": the five-coordinate ferrous deoxy form is high spin and the six coordinate oxy form is low spin and diamagnetic. Many models of myoglobin have been synthesized as part of a broad interest in transition metal dioxygen complexes. A well known example is the picket fence porphyrin, which consists of a ferrous complex of a sterically bulky derivative of tetraphenylporphyrin. In the presence of an imidazole ligand, this ferrous complex reversibly binds O2; the O2 substrate adopts a bent geometry. A key property of this model is the slow formation of the μ-oxo dimer, an inactive diferric state. In nature, such deactivation pathways are suppressed by protein matrix that prevents close approach of the Fe-porphyrin assemblies. Cytoglobin Hemoglobin Hemoprotein Neuroglobin Phytoglobin Myoglobinuria - The presence of myoglobin in the urine Ischemia-reperfusion injury of the appendicular musculoskeletal system Online Mendelian Inheritance in Man 160000 human genetics The Myoglobin Protein Protein Database featured mole
In cell biology, the cytoplasm is all of the material within a cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm; the main components of the cytoplasm are cytosol – a gel-like substance, the organelles – the cell's internal sub-structures, various cytoplasmic inclusions. The cytoplasm is about 80% water and colorless; the submicroscopic ground cell substance, or cytoplasmatic matrix which remains after exclusion the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, high complex, polyphasic system in which all of resolvable cytoplasmic elements of are suspended, including the larger organelles such as the ribosomes, the plant plastids, lipid droplets, vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, processes such as cell division; the concentrated inner area is called the endoplasm and the outer layer is called the cell cortex or the ectoplasm.
Movement of calcium ions in and out of the cytoplasm is a signaling activity for metabolic processes. In plants, movement of the cytoplasm around vacuoles is known as cytoplasmic streaming; the term was introduced by Rudolf von Kölliker in 1863 as a synonym for protoplasm, but it has come to mean the cell substance and organelles outside the nucleus. There has been certain disagreement on the definition of cytoplasm, as some authors prefer to exclude from it some organelles the vacuoles and sometimes the plastids; the physical properties of the cytoplasm have been contested in recent years. It remains uncertain how the varied components of the cytoplasm interact to allow movement of particles and organelles while maintaining the cell’s structure; the flow of cytoplasmic components plays an important role in many cellular functions which are dependent on the permeability of the cytoplasm. An example of such function is cell signalling, a process, dependent on the manner in which signaling molecules are allowed to diffuse across the cell.
While small signaling molecules like calcium ions are able to diffuse with ease, larger molecules and subcellular structures require aid in moving through the cytoplasm. The irregular dynamics of such particles have given rise to various theories on the nature of the cytoplasm. There has long been evidence, it is thought that the component molecules and structures of the cytoplasm behave at times like a disordered colloidal solution and at other times like an integrated network, forming a solid mass. This theory thus proposes that the cytoplasm exists in distinct fluid and solid phases depending on the level of interaction between cytoplasmic components, which may explain the differential dynamics of different particles observed moving through the cytoplasm, it has been proposed that the cytoplasm behaves like a glass-forming liquid approaching the glass transition. In this theory, the greater the concentration of cytoplasmic components, the less the cytoplasm behaves like a liquid and the more it behaves as a solid glass, freezing larger cytoplasmic components in place.
A cell's ability to vitrify in the absence of metabolic activity, as in dormant periods, may be beneficial as a defence strategy. A solid glass cytoplasm would freeze subcellular structures in place, preventing damage, while allowing the transmission of small proteins and metabolites, helping to kickstart growth upon the cell's revival from dormancy. There has been research examining the motion of cytoplasmic particles independent of the nature of the cytoplasm. In such an alternative approach, the aggregate random forces within the cell caused by motor proteins explain the non-Brownian motion of cytoplasmic constituents; the three major elements of the cytoplasm are the cytosol and inclusions. The cytosol is the portion of the cytoplasm not contained within membrane-bound organelles. Cytosol makes up about 70% of the cell volume and is a complex mixture of cytoskeleton filaments, dissolved molecules, water; the cytosol's filaments include the protein filaments such as actin filaments and microtubules that make up the cytoskeleton, as well as soluble proteins and small structures such as ribosomes and the mysterious vault complexes.
The inner and more fluid portion of the cytoplasm is referred to as endoplasm. Due to this network of fibres and high concentrations of dissolved macromolecules, such as proteins, an effect called macromolecular crowding occurs and the cytosol does not act as an ideal solution; this crowding effect alters. Organelles, are membrane-bound structures inside the cell that have specific functions; some major organelles that are suspended in the cytosol are the mitochondria, the endoplasmic reticulum, the Golgi apparatus, lysosomes, in plant cells, chloroplasts. The inclusions are small particles of insoluble substances suspended in the cytosol. A huge range of inclusions exist in different cell types, range from crystals of calcium oxalate or silicon dioxide in plants, to granules of energy-storage materials such as starch, glycogen, or polyhydroxybutyrate. A widespread example are lipid droplets, which are spherical droplets composed of lipids and proteins that are used in both prokaryotes and eukaryotes as a way of storing lipids such as fatty acids and sterols.
Lipid droplets make up much of the volume of adipocytes, which are specialized lipid-st
Calcium is a chemical element with symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air, its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust and the third most abundant metal, after iron and aluminium; the most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life. The name derives from Latin calx "lime", obtained from heating limestone; some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are used in many industries: in foods and pharmaceuticals for calcium supplementation, in the paper industry as bleaches, as components in cement and electrical insulators, in the manufacture of soaps.
On the other hand, the metal in pure form has few applications due to its high reactivity. Calcium is the fifth-most abundant element in the human body; as electrolytes, calcium ions play a vital role in the physiological and biochemical processes of organisms and cells: in signal transduction pathways where they act as a second messenger. Calcium ions outside cells are important for maintaining the potential difference across excitable cell membranes as well as proper bone formation. Calcium is a ductile silvery metal whose properties are similar to the heavier elements in its group, strontium and radium. A calcium atom has twenty electrons, arranged in the electron configuration 4s2. Like the other elements placed in group 2 of the periodic table, calcium has two valence electrons in the outermost s-orbital, which are easily lost in chemical reactions to form a dipositive ion with the stable electron configuration of a noble gas, in this case argon. Hence, calcium is always divalent in its compounds, which are ionic.
Hypothetical univalent salts of calcium would be stable with respect to their elements, but not to disproportionation to the divalent salts and calcium metal, because the enthalpy of formation of MX2 is much higher than those of the hypothetical MX. This occurs because of the much greater lattice energy afforded by the more charged Ca2+ cation compared to the hypothetical Ca+ cation. Calcium, strontium and radium are always considered to be alkaline earth metals. Beryllium and magnesium are different from the other members of the group in their physical and chemical behaviour: they behave more like aluminium and zinc and have some of the weaker metallic character of the post-transition metals, why the traditional definition of the term "alkaline earth metal" excludes them; this classification is obsolete in English-language sources, but is still used in other countries such as Japan. As a result, comparisons with strontium and barium are more germane to calcium chemistry than comparisons with magnesium.
Calcium metal melts at 842 °C and boils at 1494 °C. It crystallises in the face-centered cubic arrangement like strontium, its density of 1.55 g/cm3 is the lowest in its group. Calcium can be cut with a knife with effort. While calcium is a poorer conductor of electricity than copper or aluminium by volume, it is a better conductor by mass than both due to its low density. While calcium is infeasible as a conductor for most terrestrial applications as it reacts with atmospheric oxygen, its use as such in space has been considered; the chemistry of calcium is that of a typical heavy alkaline earth metal. For example, calcium spontaneously reacts with water more than magnesium and less than strontium to produce calcium hydroxide and hydrogen gas, it reacts with the oxygen and nitrogen in the air to form a mixture of calcium oxide and calcium nitride. When finely divided, it spontaneously burns in air to produce the nitride. In bulk, calcium is less reactive: it forms a hydration coating in moist air, but below 30% relative humidity it may be stored indefinitely at room temperature.
Besides the simple oxide CaO, the peroxide CaO2 can be made by direct oxidation of calcium metal under a high pressure of oxygen, there is some evidence for a yellow superoxide Ca2. Calcium hydroxide, Ca2, is a strong base, though it is not as strong as the hydroxides of strontium, barium or the alkali metals. All four dihalides of calcium are known. Calcium carbonate and calcium sulfate are abundant minerals. Like strontium and barium, as well as the alkali metals and the divalent lanthanides europium and ytterbium, calcium metal dissolves directly in liquid ammonia to give a dark blue solution. Due to the large size of the Ca2+ ion, high coordination numbers are common, up to 24 in some intermetallic compounds such as CaZn13. Calcium is complexed by oxygen chelates such as EDTA and polyphosphates, which are useful in an
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a reactive nonmetal, an oxidizing agent that forms oxides with most elements as well as with other compounds. By mass, oxygen is the third-most abundant element in the universe, after helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. As compounds including oxides, the element makes up half of the Earth's crust. Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids and fats, as do the major constituent inorganic compounds of animal shells and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. Oxygen is continuously replenished in Earth's atmosphere by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide.
Oxygen is too chemically reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone absorbs ultraviolet UVB radiation and the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation. However, ozone present at the surface is a byproduct of thus a pollutant. Oxygen was isolated by Michael Sendivogius before 1604, but it is believed that the element was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, Joseph Priestley in Wiltshire, in 1774. Priority is given for Priestley because his work was published first. Priestley, called oxygen "dephlogisticated air", did not recognize it as a chemical element; the name oxygen was coined in 1777 by Antoine Lavoisier, who first recognized oxygen as a chemical element and characterized the role it plays in combustion. Common uses of oxygen include production of steel and textiles, brazing and cutting of steels and other metals, rocket propellant, oxygen therapy, life support systems in aircraft, submarines and diving.
One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle and surrounding the vessel's neck with water resulted in some water rising into the neck. Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries Leonardo da Vinci built on Philo's work by observing that a portion of air is consumed during combustion and respiration. In the late 17th century, Robert Boyle proved. English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. In one experiment, he found that placing either a mouse or a lit candle in a closed container over water caused the water to rise and replace one-fourteenth of the air's volume before extinguishing the subjects.
From this he surmised that nitroaereus is consumed in both combustion. Mayow observed that antimony increased in weight when heated, inferred that the nitroaereus must have combined with it, he thought that the lungs separate nitroaereus from air and pass it into the blood and that animal heat and muscle movement result from the reaction of nitroaereus with certain substances in the body. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract "De respiratione". Robert Hooke, Ole Borch, Mikhail Lomonosov, Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element; this may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, modified by the chemist Georg Ernst Stahl by 1731, phlogiston theory stated that all combustible materials were made of two parts.
One part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. Combustible materials that leave little residue, such as wood or coal, were thought to be made of phlogiston. Air did not play a role in phlogiston theory, nor were any initial quantitative experiments conducted to test the idea. Polish alchemist and physician Michael Sendivogius in his work De Lapide Philosophorum Tractatus duodecim e naturae fonte et manuali experientia depromti described a substance contained in air, referring to it as'cibus vitae', this substance is identical with oxygen. Sendivogius, during his experiments performed between 1598 and 1604, properly recognized that the substance is equivalent to the gaseous byproduct released by the thermal decomposition of potassium nitrate. In Bugaj’s view, the isolation of oxygen and the proper association of the substance to that part of air, required for life, lends sufficient weight to the discovery of oxygen by Sendivogius.
Human serum albumin
Human serum albumin is the serum albumin found in human blood. It is the most abundant protein in human blood plasma, it is produced in the liver. It is soluble in monomeric. Albumin transports hormones, fatty acids, other compounds, buffers pH, maintains oncotic pressure, among other functions. Albumin is synthesized in the liver as preproalbumin, which has an N-terminal peptide, removed before the nascent protein is released from the rough endoplasmic reticulum; the product, proalbumin, is in turn cleaved in the Golgi vesicles to produce the secreted albumin. The reference range for albumin concentrations in serum is 35–50 g/L, it has a serum half-life of 20 days. It has a molecular mass of 66.5 kDa. The gene for albumin is located on chromosome 4 in locus 4q13.3 and mutations in this gene can result in anomalous proteins. The human albumin gene is 16,961 nucleotides long from the putative'cap' site to the first poly addition site, it is split into 15 exons that are symmetrically placed within the 3 domains thought to have arisen by triplication of a single primordial domain.
Maintains oncotic pressure Transports thyroid hormones Transports other hormones, in particular, ones that are fat-soluble Transports fatty acids to the liver and to myocytes for utilization of energy Transports unconjugated bilirubin Transports many drugs. As such, it is not a valid marker of nutritional status. Serum albumin concentration is 35–50 g/L. Hypoalbuminemia means low blood albumin levels; this can be caused by: Liver disease. This condition is due to dehydration. Hyperalbuminemia has been associated with high protein diets. Human albumin solution or HSA is available for medical use at concentrations of 5–25%. Human albumin is used to replace lost fluid and help restore blood volume in trauma and surgery patients. A Cochrane systematic review of 37 trials found no evidence that albumin, compared with cheaper alternatives such as saline, reduces the risk of dying. Human serum albumin has been used as a component of a frailty index, it has not been shown to give better results than other fluids when used to replace volume, but is used in conditions where loss of albumin is a major problem, such as liver disease with ascites.
It has been known for a long time that human blood proteins like hemoglobin and serum albumin may undergo a slow non-enzymatic glycation by formation of a Schiff base between ε-amino groups of lysine residues and glucose molecules in blood. This reaction can be inhibited in the presence of antioxidant agents. Although this reaction may happen elevated glycoalbumin is observed in diabetes mellitus. Glycation has the potential to alter the biological structure and function of the serum albumin protein. Moreover, the glycation can result in the formation of Advanced Glycation End-Products, which result in abnormal biological effects. Accumulation of AGEs leads to tissue damage via alteration of the structures and functions of tissue proteins, stimulation of cellular responses, through receptors specific for AGE-proteins, generation of reactive oxygen intermediates. AGEs react with DNA, thus causing mutations and DNA transposition. Thermal processing of proteins and carbohydrates brings major changes in allergenicity.
AGEs represent many of the important neoantigens found in cooked or stored foods. They interfere with the normal product of nitric oxide in cells. Although there are several lysine and arginine residues in the serum albumin structure few of them can take part in the glycation reaction, it is not clear why only these residues are glycated in serum albumin, but it is suggested that non-covalent binding of glucose to serum albumin prior to the covalent bond formation might be the reason. The albumin is the predominant protein in most body fluids, its Cys34 represents the largest fraction of free thiols within body; the albumin Cys34 thiol exists in both oxidized forms. In plasma of healthy young adults, 70–80% of total HSA contains the free sulfhydryl group of Cys34 in a reduced form or mercaptoalbumin. However, in pathological states characterized by oxidative stress and during the aging process, the oxidized form, or non-mercaptoalbumin, could predominate; the albumin thiol reacts with radical hydroxyl, hydrogen peroxide and the reactive nitrogen species as peroxynitrite, have been shown to oxidize Cys34 to sulfenic acid derivate, it can be recycled to mercapto-albumin.