This is a working overview of angiotensin IV, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-29. Anything still debated is marked as such rather than presented as settled.
Dihexa is a synthetic peptide with the chemical name N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide, and it is structurally related to angiotensin IV, a naturally occurring peptide fragment. Researchers developed it as a modified analog intended to alter stability and activity relative to the parent peptide. Its short sequence and fatty acid chain distinguish it from many endogenous peptides, and published studies often describe it under the abbreviation dihexa. The compound is classified as a laboratory compound rather than an approved therapeutic in most jurisdictions.
Early laboratory work focused on its effects on synaptic connectivity and neuronal signaling. In cell and animal models, dihexa has been reported to promote the formation of new synapses, a process called synaptogenesis. These findings have generated interest in cognitive research, but the evidence base remains mostly preclinical. Human clinical trials with clear safety and efficacy endpoints are limited or absent in the public literature. Whether these effects translate to humans is an open question.
The proposed mechanism involves interaction with the hepatocyte growth factor (HGF) system and its receptor, c-Met. Dihexa is described in some studies as an HGF mimetic, meaning it may mimic or enhance HGF-mediated signaling. Activation of c-Met can influence cell growth, survival, and cytoskeletal remodeling, pathways that intersect with synaptic plasticity. However, the precise binding targets and downstream events for dihexa are not fully established, and alternative mechanisms have been suggested.
Dihexa is a synthetic peptide that has been examined in laboratory and animal research. Its design is based on angiotensin IV, a naturally occurring peptide fragment produced in the body. The short name dihexa appears in scientific papers and online discussions, while the full chemical name describes a modified peptide chain. It is not a vitamin, mineral, or plant-derived compound. Suppliers typically present it as a research chemical rather than an approved medicine.
The full name often given is N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide. This name indicates a chain containing tyrosine, isoleucine, and a six-carbon amino acid derivative. Databases list a CAS Registry Number and a molecular formula for the compound. The peptide is small compared with proteins, and its structure allows it to be studied in cell cultures and animal models. Exact identity depends on the supplier's synthesis and purification process. Minor impurities can remain after synthesis.
Chemically, dihexa belongs to a broader group of angiotensin IV analogs. Researchers have modified the natural peptide to alter stability, binding, or distribution. Such changes can affect how the molecule behaves in experiments. The parent peptide angiotensin IV is involved in various physiological processes, but the modified analog is not identical to it. Public summaries sometimes blur the distinction between the natural fragment and the synthetic research compound. This distinction matters when interpreting study results.
| Property | Value | Notes |
|---|---|---|
| Chemical name | N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide | Common full name in research literature. |
| Class | Synthetic peptide | Modified angiotensin IV analog. |
| Related compound | Angiotensin IV | Parent peptide fragment. |
| Proposed target | HGF/c-Met pathway | Described as an HGF mimetic; not fully confirmed. |
| Development status | Preclinical research | No widely approved clinical use. |
The compound originated from work on angiotensin IV, a peptide fragment of the renin-angiotensin system. Researchers modified angiotensin IV-related structures to produce molecules with altered stability and activity. Dihexa emerged from that effort and was reported to promote dendritic spine growth in cultured neurons. Some studies link its effects to hepatocyte growth factor signaling and the c-Met receptor, while other work points to insulin-regulated aminopeptidase. The precise primary target remains a subject of investigation, and findings may depend on cell type, assay conditions, and species.
In animal research, dihexa has been administered through several routes, and reports describe improved performance on spatial learning and memory tasks in rodents. These results are frequently cited in discussions of nootropic compounds. However, species differences, small sample sizes, and varied testing protocols limit how far the findings can be generalized. No large randomized controlled trials in humans have established efficacy or long-term safety. Claims about human cognitive enhancement therefore remain speculative, and the compound is best described as an experimental laboratory substance rather than a proven therapeutic or supplement.
Dihexa is not approved as a medicine in major regulatory jurisdictions. It is commonly sold as a research chemical for laboratory use, though such products may not be standardized or independently verified. Scientific literature on dihexa includes in vitro assays, rodent studies, and reviews that discuss its proposed mechanism. The distinction between peer-reviewed findings and commercial promotion is important when evaluating available information. Open questions include its precise binding interactions, pharmacokinetics, and whether animal results translate to human biology.
Dihexa is a synthetic peptide derived from angiotensin IV, a naturally occurring fragment of the renin-angiotensin system. Researchers modified the angiotensin IV structure to improve metabolic stability and central nervous system activity. It is frequently described as a hepatocyte growth factor mimetic because it can activate the c-Met receptor pathway in experimental systems. Its development reflects interest in small peptides that influence synaptic plasticity and cognitive processes. Most information comes from preclinical studies rather than controlled human trials.
The compound has been examined in animal models for effects on learning, memory, and synaptic connectivity. Some reports describe increased dendritic spine density and improved performance on certain behavioral tasks after administration in rodents. These findings are often cited in discussions of nootropic research peptides, but replication across independent laboratories remains limited. The absence of published phase 1 or phase 2 clinical trial data makes it difficult to assess safety, effective routes, or long-term outcomes in humans. Consequently, claims about cognitive benefits in people remain speculative.
Successful international boycotts of Australian Merino wool in the early 2000s set those invested in Australian sheep rearing on the hunt for alternatives. The publicity generated intense interest in finding a replacement for mulesing that domestic and international consumers would accept. An adaptation of the freeze branding process was hit upon in the 2010s. The new technique was quickly christened steining after its designer, John Steinfort, an Australian veterinary scientist. In 2019 Australian Wool Network (AWN), a private corporation servicing the Australian wool industry, provided Steinfort funding to commercialize the technique. During steining hollow cupronickel clamping jaws about 4 inches (10 cm) long are used to pinch up rolls of skin beneath the tail and near the anus of a lamb. No shaving is required in this application of freeze branding. Once sufficient skin is in the clamps liquid nitrogen is pumped through the jaws and onto the pinched skin. This rapidly freezes the lamb's skin as it drips out of the jaws and through the animal's fleece. The goal is to achieve a level of cellular injury that prevents future hair growth but not so much that a 3rd-degree cold burn is created. Pinching the skin is thought to mitigate the degree of cold burn by removing it somewhat from the muscles and connective tissue beneath. The treated skin goes through the same stages of healing seen in the long method of freeze-branding larger livestock, concluding with permanent hairlessness.
The In-N-Out menu consists of three burger varieties: hamburger, cheeseburger, and "Double-Double" (two hamburger patties and two slices of cheese). French fries and fountain drinks are available, as well as three flavors of milkshakes. The hamburgers come with lettuce, tomato, with or without onions (the customer is asked upon ordering, and may have them fresh or grilled), and a sauce, which is called "spread" (a Thousand Island dressing variant). There are additional named items not on the menu, but available at every In-N-Out. These variations reside on the chain's "secret menu", though the menu is accessible on the company's website. These variations include 3×3 (which has three patties and three slices of cheese), 4×4 (four patties and four slices of cheese), Neapolitan shakes, grilled cheese sandwich (consists of the same ingredients as the burgers except the meat, plus two slices of melted cheese), Protein Style (wrap with lettuce; consists of the same ingredients as the burgers except buns), and Animal Style (cooked in a thin layer of mustard, adding condiments including pickles, grilled onions, and extra spread). Animal Style fries come with two slices of melted cheese, spread, and grilled onions on top. Whole or sliced chili peppers are also available by request. Both Protein and Animal Style are house specialties that the company has trademarked because of their association with the chain.
== Origins of pathology == Early understanding of the origins of diseases constitutes the earliest application of the scientific method to the field of medicine, a development which occurred in the Middle East during the Islamic Golden Age and in Western Europe during the Italian Renaissance. The Greek physician Hippocrates, the founder of scientific medicine, was the first to deal with the anatomy and the pathology of human spine. Galen developed an interest in anatomy from his studies of Herophilus and Erasistratus. The concept of studying disease through the methodical dissection and examination of diseased bodies, organs, and tissues may seem obvious today, but there are few if any recorded examples of true autopsies performed prior to the second millennium. Though the pathology of contagion was understood by Muslim physicians since the time of Avicenna (980–1037) who described it in The Canon of Medicine (c. 1020), the first physician known to have made postmortem dissections was the Arabian physician Avenzoar (1091–1161) who proved that the skin disease scabies was caused by a parasite, followed by Ibn al-Nafis (b. 1213) who used dissection to discover pulmonary circulation in 1242. In the 15th century, anatomic dissection was repeatedly used by the Italian physician Antonio Benivieni (1443–1502) to determine cause of death. Antonio Benivieni is also credited with having introduced necropsy to the medical field. Perhaps the most famous early gross pathologist was Giovanni Morgagni (1682–1771).
Sources: en.wikipedia.org
Rocha-Méndez et al. (2026) report evidence from the study of mitochondrial genomes of European fallow deers from the Neumark-Nord sites (Germany) indicative of loss of genetic diversity of the species since the Pleistocene, recovering the studied extinct population from a single Eemian locality with as much genetic diversity as seen in extant population with a Eurasian range. Chung & Cho (2026) describe new antler remains of Elaphurus formosanus from the Pleistocene of Taiwan and support recognition of the species as distinct. Amanova, Drucker & Fontana (2026) reconstruct the ecology and habitat use of red deers from the Epigravettian sequence of Riparo Tagliente (Italy) on the basis of the study of carbon and oxygen isotopic composition of their tooth enamel, reporting evidence of a diet based on C3 plants and life in the landscape dominated by open woodland environments. Kubo, Yamazaki & Taniguchi (2026) reconstruct the diet of early to mid-Holocene sika deers from the Iyai Rockshelter Site (Japan) on the basis of the study on their tooth wear texture, reporting evidence of abrasive food in their diets and short-term temporal changes in foraging conditions. Martínez-Polanco (2026) determines diet of extant Neotropical deer (including local dietary variation within species) on the basis of the study of their tooth wear, providing reference data that can be used to determine diets of fossil deer and other small- to medium-sized ungulates.
=== Mechanism === The components of the ear involved in cauliflower ear are the outer skin, the perichondrium, and the cartilage. The outer ear skin is tightly adherent to the perichondrium because there is almost no subcutaneous fat on the anterior of the ear. This leaves the perichondrium relatively exposed to damage from direct trauma and shear forces, created by a force pushing across the ear like a punch, and increasing the risk of hematoma formation. In an auricular hematoma, blood accumulates between the perichondrium and cartilage. The hematoma mechanically obstructs blood flow from the perichondrium to the avascular cartilage. This lack of perfusion puts the cartilage at risk for becoming necrotic and/or infected. If left untreated, disorganized fibrosis and cartilage formation will occur around the aforementioned cartilaginous components. Consequently, the concave pinna fills with disorganized connective tissue. The cartilage then deforms and kinks, resulting in the distinctive appearance somewhat resembling a cauliflower. Rapid evacuation of the hematoma restores close contact between the cartilage and perichondrium, thereby reducing the likelihood of deformity by minimizing the ischemia that would otherwise result from a remaining hematoma. Auricular hematoma most often occurs in the potential space between the helix and the antihelix (scapha) and extends anteriorly into the fossa triangularis. Less frequently, the hematoma may form in the concha or the area in and around the external auditory meatus.
=== Underrepresentation === In non-Westernized countries, including those in Africa (excluding South Africa), eating disorders are less frequently reported and studied compared to Western countries, with available data mostly limited to case reports and isolated studies rather than prevalence investigations. Theories to explain these lower rates of eating disorders, lower reporting, and lower research rates in these countries include the attention to effects of westernization and culture change on the prevalence of anorexia. Athletes are often overlooked as anorexic. Research emphasizes the importance to take athletes' diet, weight and symptoms into account when diagnosing anorexia, instead of just looking at weight and BMI. For athletes, ritualized activities such as weigh-ins place emphasis on gaining and losing large amounts of weight, which may promote the development of eating disorders among them. Furthermore, the competitive mindset of elite athletes makes them especially vulnerable to anorexia nervosa. The disorder is often largely rooted in a desire to maintain control over one's own life. The highly competitive mindset that athletic pursuits can easily translate to the world of disordered eating. Eating becomes "like a game" or "challenge", where the athlete is completely focused on "winning the game"; one elite swimmer with severe anorexia nervosa recalls that "it was always about losing more" and she "never wanted the game to be over".
The spores are elliptical to spindle-shaped, with dimensions of 12–17 by 5–7 μm. The basidia, the spore-bearing cells, are produced in a layer lining the tubes, and arrange themselves so their ends are facing the center of the tube; this layer of cells is known technically as a hymenium. The basidia are thin-walled, mostly attached to four spores, and measure 25–30 by 8–10 μm. Another cell type present in the hymenium is the cystidia, larger sterile cells that protrude beyond the basidia into the lumen of the hymenium and act as air traps, regulating humidity. B. edulis has pleurocystidia (cystidia located on the face of a pore) that are thin-walled, roughly spindle-shaped to ventricose, and 30–45 by 7–10 μm; the "stuffed" feature of the hymenium is caused by cheilocystidia—cells found on the edges of the pores. The hyphae of B. edulis do not have clamp connections.
Sources: en.wikipedia.org
The conformational mobility of serpins provides a key advantage over static lock-and-key protease inhibitors. In particular, the function of inhibitory serpins can be regulated by allosteric interactions with specific cofactors. The X-ray crystal structures of antithrombin, heparin cofactor II, MENT and murine antichymotrypsin reveal that these serpins adopt a conformation wherein the first two amino acids of the RCL are inserted into the top of the A β-sheet. The partially inserted conformation is important because co-factors are able to conformationally switch certain partially inserted serpins into a fully expelled form. This conformational rearrangement makes the serpin a more effective inhibitor. The archetypal example of this situation is antithrombin, which circulates in plasma in a partially inserted relatively inactive state. The primary specificity determining residue (the P1 arginine) points toward the body of the serpin and is unavailable to the protease. Upon binding a high-affinity pentasaccharide sequence within long-chain heparin, antithrombin undergoes a conformational change, RCL expulsion, and exposure of the P1 arginine. The heparin pentasaccharide-bound form of antithrombin is, thus, a more effective inhibitor of thrombin and factor Xa. Furthermore, both of these coagulation proteases also contain binding sites (called exosites) for heparin. Heparin, therefore, also acts as a template for binding of both protease and serpin, further dramatically accelerating the interaction between the two parties.
== Life == Richard Laurence Millington Synge was born in West Kirby on 28 October 1914, the son of Lawrence Millington Synge, a Liverpool stock-broker, and his wife, Katherine C. Swan. Synge was educated at the Old Hall in Wellington, Shropshire and at Winchester College. He then studied Chemistry at Trinity College, Cambridge. He spent his entire career in research, at the Wool Industries Research Association, Leeds (1941–1943), Lister Institute for Preventive Medicine, London (1943–1948), Rowett Research Institute, Aberdeen (1948–1967), and Food Research Institute, Norwich (1967–1976). It was during his time in Leeds that he worked with Archer Martin, developing partition chromatography, a technique used in the separation mixtures of similar chemicals, that revolutionised analytical chemistry. Between 1942 and 1948 he studied peptides of the protein group gramicidin, work later used by Frederick Sanger in determining the structure of insulin. In March 1950 he was elected a Fellow of the Royal Society for which his candidature citation read:
=== Everton bid === In September 2023, 777 Partners agreed to buy Farhad Moshiri's 94.1% shareholding in English Premier League team Everton F.C. In April 2024, with the deal not complete and after the 777-owned Australian airline Bonza entered voluntary administration, Everton called upon the services of insolvency advisers Teneo. Amid lawsuits against 777 Partners in other countries, the Everton Shareholders' Association wrote to Moshiri requesting that he terminate the deal. 777 enlisted B. Riley Financial for advice to complete the deal. According to 777's own lawyers, Wander and Pasko resigned as managers of the company on May 6, 2024, but remained as its 100% owners. On June 1, 2024, the deadline for the deal to be completed expired.
=== Cost === In a 2020 cost-effectiveness study dupilumab was inferior to endoscopic sinus surgery (ESS): At a 36-year time horizon dupilumab treatment cost $536,420.22 and produced 8.95 QALYs (quality-adjusted life years), while ESS cost roughly one tenth at $50,436.99 and produced 9.80 QALYs.
June: Jupiter IRBM deployment to Turkey begins, joining the Jupiters deployed to Italy as well as the Thor IRBMs deployed to the UK as nuclear missiles placed within striking distance of Moscow. July 11: North Korea and China sign a defensive treaty, the Sino-North Korean Mutual Aid and Cooperation Friendship Treaty. July 19: The Nicaraguan Revolution begins. August 13: The Berlin Wall is built by the Soviets following the breakdown in talks to decide the future of Germany. August 17: Alliance for Progress aid to Latin America from the United States begins. September 1: The Soviet Union resumed testing of nuclear weapons in the atmosphere. The Eritrean War of Independence begins. September 4: John F. Kennedy signs the Foreign Assistance Act. September 18: UN Secretary General Dag Hammarskjöld dies in a plane crash on his way to negotiate a ceasefire in Katanga amidst the Congo Crisis September 28: Syria withdraws from the United Arab Republic. October 17: 22nd Soviet Party Congress held in USSR. October 27: Checkpoint Charlie standoff between US and Soviet tanks begins. October 31: The Soviet Union detonates the Tsar Bomba, the most powerful thermonuclear weapon ever tested, with an explosive yield of some 50 megatons. November 18: John F. Kennedy authorizes the deployment of 18,000 military advisors to support the struggle against communist insurgents in South Vietnam. December 2: Fidel Castro openly describes himself as a Marxist–Leninist. December 18: Republic of India invades the former Portuguese territory of Goa.
Sources: en.wikipedia.org
Dihexa is a synthetic peptide analog of angiotensin IV, often described as an HGF mimetic in research literature. It is studied for effects on synaptic connectivity in laboratory models. It is not an approved medication.
No, dihexa is a synthetic compound derived from the structure of angiotensin IV. Angiotensin IV occurs naturally, but dihexa has modifications that change its properties. It is not a standard dietary component.
The main hypothesis is that dihexa interacts with the hepatocyte growth factor system, possibly through c-Met signaling. This interaction may influence synaptogenesis and neuronal plasticity. The exact molecular target remains an active area of study.
Dihexa is a synthetic peptide modeled on angiotensin IV. It is used in laboratory and animal research, not as an approved medicine. Human effects remain poorly characterized.