If you have been reading about Enkephalinase and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-07-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analog of the tetrapeptide tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Reported consistently across pharmacopoeial descriptions |
| Appearance | White to off-white lyophilized powder | Typical form of research-grade material |
| Solubility | Freely soluble in water | Aqueous buffers; poor in nonpolar solvents |
| Typical storage temperature | -20 degrees Celsius | Lyophilized powder; protect from moisture |
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Biotechniques Laboratory electrophoresis demonstration, from the University of Utah's Genetic Science Learning Center Discontinuous native protein gel electrophoresis[link removed] Drinking straw electrophoresis How to run a DNA or RNA gel Animation of gel analysis of DNA restriction Step by step photos of running a gel and extracting DNA A typical method from wikiversity
He became a fellow of the American Physical Society in 1959, was elected to the National Academy of Sciences in 1979, and was named a Fellow of the American Academy of Arts and Sciences (AAAS) in 1983. Redfield received the Max Delbruck Prize from the American Physical Society in 2006. In 2007 he was recognized with the Russell Varian Prize for contributing the Redfield Relaxation Theory to the field of nuclear magnetic resonance. Redfield is descended from a family of pioneering scientists, including his father, Alfred C. Redfield, his second great-grandfather, William Charles Redfield, and his great-grandfather, the naturalist John Howard Redfield.
=== Human health === When CEC bypass water filtration systems and contaminate drinking water or accumulate in the food chain, they can also cause risks to human health. Chronic exposure to low doses of CEC has been linked to various health issues. For example, certain pharmaceutical CEC and EDCs have been associated with hormonal imbalances, increased risks of certain cancers, and developmental problems. The antibiotics present in the environment can also contribute to the development of antibiotic-resistant bacteria, which poses a serious threat to human health by reducing the effectiveness of antibiotic treatments. Studies have shown that even at low concentrations, the presence of CEC in drinking water can correlate with neurological disorders and can decrease cognitive function over time. Certain perfluoroalkyl substances (PFAS), which are a type of CEC, have been linked to different adverse health outcomes like increased cholesterol levels, changes in liver enzymes, and reduced vaccine efficacy, which raises concerns about widespread exposure to these chemicals. The CDC also identifies exposure to high levels of CEC with negative effects on the immune system, by compromising the body's ability to fight infections and increasing the risk of rheumatological diseases. Exposure to a combination of various CEC, which can occur through contaminated drinking water or food chains, may lead to cumulative on human health that are not yet fully understood.
Medications for treatment of cases that do not improve include calcium channel blockers and iloprost. There is little evidence that alternative medicine reduce symptoms. Severe Raynaud's may in rare cases lead to complications, specifically skin sores or gangrene. About 4% of people have the condition. Onset of the primary form is typically between ages 15 and 30. The secondary form usually affects older people. Both forms are more common in cold climates.
== External links == Simply stated at mdausa.org[link removed] Creatine+Kinase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) CPK isoenzymes test MedlinePlus Encyclopedia: 003504 CK at Lab Tests Online
Sources: en.wikipedia.org
== Other names == Drop sets and the technique also go by the names breakdowns, burnouts, descending sets, triple-drops (when a total of three different weights are used), down the rack or running the rack (when using dumbbells), up the stack (because with a weight machine, the pin is moved up the stack of plates with each drop in weight), strip sets (when you "strip" weights off the ends of a bar), or the stripping technique (so called because of "stripping" weight plates off with each drop in weight).
==== Fungal ==== Oral fungal infections are most commonly caused by different Candida species, such as Candida albicans, Candida glabrata and Candida tropicalis resulting in oral candidiasis. There are several predisposing factors to fungal infections, such as diabetes and recent use of antibiotics or steroid inhalers. Management includes identifying and addressing contributory factors, the use of topical or systemic antifungal agents, and oral hygiene instruction. Different presentations of oral candidiasis include:
==== Anabolic/androgenic steroid use ==== This period also saw the rise of anabolic steroids in bodybuilding and many other sports. More significant use began with Arnold Schwarzenegger, Sergio Oliva, and Lou Ferrigno in the late 1960s and early 1970s, and continuing through the 1980s with Lee Haney, the 1990s with Dorian Yates, Ronnie Coleman, and Markus Rühl, and up to the present day. Bodybuilders such as Greg Kovacs attained mass and size never seen previously but were not successful at the pro level. Others were renowned for their spectacular development of a particular body part, like Tom Platz or Paul Demayo for their leg muscles. At the time of shooting Pumping Iron, Schwarzenegger, while never admitting to steroid use until long after his retirement, said, "You have to do anything you can to get the advantage in competition". He would later say that he did not regret using steroids. To combat anabolic steroid use and in the hopes of becoming a member of the IOC, the IFBB introduced doping tests for both steroids and other banned substances. Although doping tests occurred, the majority of professional bodybuilders still used anabolic steroids for competition. During the 1970s, the use of anabolic steroids was openly discussed, partly due to the fact they were legal. In the Anabolic Steroids Control Act of 1990, the U.S. Congress placed anabolic steroids into Schedule III of the Controlled Substances Act (CSA). In Canada, steroids are listed under Schedule IV of the Controlled Drugs and Substances Act, enacted by the federal Parliament in 1996.
=== Adrenomedullin receptor === CALCRL binds Ramp2 to form the adrenomedullin receptor 1 (AM1), while it binds Ramp3 to form adrenomedullin receptor 2 (AM2). Adrenomedullin is a multifunctional 52 amino acid peptide widely expressed throughout the body. Its most prominent functions include regulation of blood pressure, endothelial barrier development and stability, and inflammation. Administration of adrenomedullin causes vasodilation and decreased blood pressure via binding to its receptors.
Sources: en.wikipedia.org
==== Solution and precipitation ==== The diagram above illustrates the point that a precipitate that is not one of the main species in the solution equilibrium may be formed. At pH just below 5.5 the main species present in a 5 μM solution of Al3+ are aluminium hydroxides Al(OH)2+, AlOH+2 and Al13(OH)7+32, but on raising the pH Al(OH)3 precipitates from the solution. This occurs because Al(OH)3 has a very large lattice energy. As the pH rises more and more Al(OH)3 comes out of solution. This is an example of Le Châtelier's principle in action: Increasing the concentration of the hydroxide ion causes more aluminium hydroxide to precipitate, which removes hydroxide from the solution. When the hydroxide concentration becomes sufficiently high the soluble aluminate, Al(OH)−4, is formed. Another common instance where precipitation occurs is when a metal cation interacts with an anionic ligand to form an electrically neutral complex. If the complex is hydrophobic, it will precipitate out of water. This occurs with the nickel ion Ni2+ and dimethylglyoxime, (dmgH2): in this case the lattice energy of the solid is not particularly large, but it greatly exceeds the energy of solvation of the molecule Ni(dmgH)2.
13 July to 15 August The 2nd Brigade, 101st Airborne Division and ARVN 54th Regiment, 1st Division launched Operation Campbell Streamer in the Bạch Mã area near Huế. The operation results in 51 PAVN killed and one captured.
Theranos Inc. () was an American privately held corporation that was touted as a breakthrough health technology company. Founded in 2003 by then–19-year-old Elizabeth Holmes, Theranos raised more than US$700 million from venture capitalists and private investors, resulting in a $9 billion valuation at its peak in 2013 and 2014. The company falsely claimed that it had devised blood tests that could be performed rapidly and accurately, while requiring very small amounts of blood, all using compact automated devices that the company had developed. A turning point came in 2015, when medical research professor John Ioannidis, and later, professor of clinical biochemistry Eleftherios Diamandis, along with investigative journalist John Carreyrou of The Wall Street Journal, questioned the validity of Theranos's technology. The company faced a string of legal and commercial challenges from medical authorities, investors, the U.S. Securities and Exchange Commission (SEC), the Centers for Medicare and Medicaid Services (CMS), state attorneys general, former business partners, patients, and others. By June 2016, Forbes estimated that Holmes' personal net worth had dropped from $4.5 billion to "nothing". After several years of struggle, lawsuits, and sanctions from CMS, what remained of the company was dissolved in September 2018. Theranos, Holmes, and former company president Sunny Balwani were charged with fraud by the SEC in 2018.
Sources: en.wikipedia.org
Selank is a synthetic seven-amino-acid peptide modeled on tuftsin, a fragment of the immunoglobulin G heavy chain. It was designed in Russia to combine anxiolytic and immunomodulatory properties in one molecule.
The first four residues of Selank reproduce the tuftsin sequence Thr-Lys-Pro-Arg. A Pro-Gly-Pro extension at the C-terminus was added to slow enzymatic breakdown and extend residence time.
It holds marketing authorization in Russia, where nasal drop formulations are sold. No equivalent approval exists in the European Union, the United States, or most other countries.
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.