The short version of reduced glutathione fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-06. Anything still debated is marked as such rather than presented as settled.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It contains an unusual gamma-glutamyl bond between glutamate and cysteine, which resists cleavage by many peptidases. The reduced form, GSH, carries a thiol group on cysteine and is the dominant intracellular form in most cells. Its structure allows it to participate in redox reactions and to serve as a sulfur donor. The oxidized form, GSSG, consists of two GSH molecules joined by a disulfide bond.
In cells, glutathione helps maintain the reducing environment of the cytosol and supports enzymes that counteract reactive oxygen species. It acts as a cofactor for glutathione peroxidases, which reduce hydrogen peroxide and lipid peroxides, and for glutathione S-transferases, which conjugate electrophiles. The ratio of GSH to GSSG is often used as an indicator of oxidative stress, although the ratio can vary by compartment and cell type. Glutathione also stores cysteine, an amino acid that can be limiting for protein synthesis and antioxidant defense.
Synthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine. The first step is rate-limiting and is influenced by cysteine availability and feedback inhibition by GSH. Breakdown involves gamma-glutamyl transferase and subsequent peptidases, which release constituent amino acids for reuse. Because turnover differs among tissues, measurements from blood, plasma, and tissues are not directly interchangeable. Research continues to clarify how compartment-specific pools are regulated in health and disease.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It occurs in nearly all living cells, with highest concentrations in liver, kidney, and red blood cells, and exists in reduced (GSH) and oxidized disulfide (GSSG) forms. The cysteine thiol group enables reversible oxidation and reduction reactions. This property makes glutathione a central participant in cellular redox balance. The balance between these forms is often used as an indicator of oxidative stress.
Glutathione synthesis proceeds in two ATP-dependent steps catalyzed by glutamate-cysteine ligase and glutathione synthetase. The first step joins glutamate and cysteine to form gamma-glutamylcysteine and is generally rate-limiting. The second step adds glycine to complete the tripeptide. Cysteine availability, feedback inhibition by glutathione, and oxidative conditions influence flux through this pathway. The pathway is conserved across many organisms, and degradation by gamma-glutamyl transpeptidase and related peptidases recycles amino acids for new synthesis.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | For reduced glutathione; the oxidized dimer has two sulfur atoms. |
| Molar mass | 307.32 g/mol | Calculated for the reduced form. |
| Appearance | White to off-white crystalline powder | Typical for solid reagent; solutions are usually colorless. |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar organic solvents. |
| Typical storage | -20 °C, desiccated, protected from light | Limits oxidation, moisture uptake, and degradation. |
== Further reading == Hofmeister F. (1888) Arch. Exptl. Pathol. Pharmakol., 24, 247. Zhang, Y; Cremer, P (December 2006). "Interactions between macromolecules and ions: The Hofmeister series". Current Opinion in Chemical Biology. 10 (6): 658–63. doi:10.1016/j.cbpa.2006.09.020. PMID 17035073. Zhou, Huan-Xiang (October 2005). "Interactions of macromolecules with salt ions: an electrostatic theory for the Hofmeister effect". Proteins: Structure, Function, and Bioinformatics. 61 (1): 69–78. doi:10.1002/prot.20500. PMID 16044460. S2CID 4996928. Tanford C and Reynolds J. (2001) Nature's robots: a history of proteins, Oxford University Press. ISBN 0-19-850466-7 Creighton TE. (1993) Proteins, 2nd ed., W. H. Freeman. ISBN 0-7167-2317-4 Jencks WP. (1969) Catalysis in Chemistry and Enzymology, Dover republication (1987). ISBN 0-486-65460-5 Collins, KD.; Washabaugh, MW. (1985). "The Hofmeister effect and the behaviour of water at interfaces". Q Rev Biophys. 18 (4): 323–422. doi:10.1017/s0033583500005369. PMID 3916340. John Leo, Abernethy (1967). "Franz Hofmeister - The impact of his life and research on chemistry". Journal of Chemical Education. 44 (3): 177–80. Bibcode:1967JChEd..44..177A. doi:10.1021/ed044p177. PMID 5343300.
=== Calcium signalling disruption === Calcium ions (Ca²⁺) are essential signalling molecules for important cell functions such as membrane stability, cell growth and metabolism. Some algicidal bacterial compounds disrupt intracellular Ca²⁺ balance by causing unusual increases in Ca²⁺ levels. These heightened levels trigger signalling chains that eventually lead to cell death.
The date, published the next day, shows that almost 184,000 people in Scotland identify as LGBT. Officials confirm that the first batch of prisoners to be released early from prison in order to free up prison spaces have been freed. 28 June – Edinburgh City Council establishes an emergency polling booth at City Chambers after a number of people across Scotland reported not receiving their postal votes. The emergency polling booth, which allows those who did not receive a postal vote to cast their vote in person, will operate until 30 June. Fife Council also announces an emergency polling booth at Fife House, Glenrothes that will be open on 29 June. The final two second generation Glasgow Subway trains are taken out of service following the rollout of new third generation vehicles. 29 June – East Lothian Council becomes the third local authority to establish an emergency facility for people who have not received their postal votes.
Sources: en.wikipedia.org
Lost Coast uses the same first-person shooter gameplay as Half-Life 2. The player is equipped with weapons from Half-Life 2, including the object-manipulating gravity gun. Like Half-Life 2, the player controls Gordon Freeman. Freeman must enter a monastery that enemy Combine are using to launch heavy artillery shells into a seaside town. The player encounters Combine soldiers and headcrabs before disabling the artillery launcher and destroying an attack helicopter with RPGs. A fisherman congratulates him and Gordon teleports away.
== External links == "Calcitonin Receptors". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2007-07-23. Calcitonin+receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
Very soon the scientific papers will be agog with a new discovery which has been added to the many brilliant triumphs of Gower Street. Dr. Otto Hahn, who is working at University College, has discovered a new radioactive element, extracted from a mineral from Ceylon, named Thorianite, and possibly, it is conjectured, the substance which renders thorium radioactive. Its activity is at least 250,000 times as great as that of thorium, weight for weight. It gives off a gas (generally called an emanation), identical with the radioactive emanation from thorium. Another theory of deep interest is that it is the possible source of a radioactive element possibly stronger in radioactivity than radium itself, and capable of producing all the curious effects which are known of radium up to the present. – The discoverer read a paper on the subject to the Royal Society last week, and this should rank, when published, among the most original of recent contributions to scientific literature.
Sources: en.wikipedia.org
==== Gateway theory ==== An association has been found between adolescent exposure to nicotine by smoking conventional cigarettes and the subsequent onset of using other dependence-producing substances. Strong temporal and dose-dependent associations have been reported, and a plausible biological mechanism (via rodent and human modeling) suggests that long-term changes in the neural reward system take place as a result of adolescent smoking. Adolescent smokers of conventional cigarettes have disproportionately high rates of comorbid substance use, and longitudinal studies have suggested that early adolescent smoking may be a starting point or "gateway" for substance use later in life, with this effect more likely for persons with attention deficit hyperactivity disorder (ADHD). Although factors such as genetic comorbidity, innate propensity for risk-taking, and social influences may underlie these findings, both human neuroimaging and animal studies suggest a neurobiological mechanism also plays a role. In addition, behavioral studies in adolescent and young adult smokers have revealed an increased propensity for risk-taking, both generally and in the presence of peers, and neuroimaging studies have shown altered frontal neural activation during a risk-taking task as compared with nonsmokers.
An Ommaya reservoir is an intraventricular catheter system that can be used for the aspiration of cerebrospinal fluid or for the delivery of drugs (e.g. chemotherapy) into the cerebrospinal fluid. It consists of a catheter in one lateral ventricle attached to a reservoir implanted under the scalp. It is used to treat brain tumors, leukemia/lymphoma or leptomeningeal disease by intrathecal drug administration. In the palliative care of terminal cancer, an Ommaya reservoir can be inserted for intracerebroventricular injection (ICV) of morphine. It was originally invented in 1963 by Ayub K. Ommaya, a Pakistani-American neurosurgeon. In January 2017, researchers at University of Texas Southwestern Medical Centre used an Ommaya reservoir to measure the intracranial pressure that is regularly observed in astronauts in zero-gravity conditions.
===== United Kingdom ===== In the UK, semaglutide is available on NHS prescription for diabetes at nominal or no cost to the individual. It is also available for obesity, limited to treatment for two years.
Sources: en.wikipedia.org
GSH is the reduced form with a free thiol group, while GSSG is the oxidized disulfide-linked dimer. Most assays distinguish the two because their balance reflects redox conditions. The names are not interchangeable.
It is synthesized in the body from amino acids, so it is not classified as an essential dietary nutrient for most people. Dietary and supplemental forms are studied for their effects on tissue levels and health markers. Evidence varies by population and outcome.
The phrase highlights its high intracellular concentration and its role in several antioxidant and detoxification reactions. It is not the only antioxidant, and the term can oversimplify its functions. Scientific descriptions usually specify the pathway or enzyme involved.
GSH is the reduced thiol form, while GSSG is the disulfide-linked oxidized dimer. The GSH:GSSG ratio is used as a redox indicator, though the ratio can vary with sample handling and cell type.