Selank raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-07 and is reviewed periodically as new material appears.
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 |
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
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.
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.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
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.
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.
=== Histological staining === In his 1878 doctoral thesis on the use of aniline dyes for staining techniques, Ehrlich described mast cells on the basis of their unique staining characteristics. Since then a number of histochemical stains have been used with mast cells, including Toluidine blue, Giemsa, and combined Alcian Blue and Safranin O. Toluidine blue is one of the most common stains for acid mucopolysaccharides and glycoaminoglycans, components of mast cells granules. It is used in tissue sections to highlight components. Mast cell granules exhibit metachromasia, characteristic changes in color when stains bind to particular substances in biological tissues. In mast cell granules, toluidine blue attaches to glycosaminoglycans such as heparin and displays a purple color while other cells retain the color of the blue stain. Mature connective tissue mast cells display the effect of staining more quickly and intensively than mucosal cells and immature connective tissue mastocytes. The combined use of alcian blue and safranin О can be used to simultaneously detect both connective and mucosal mast cells. Heparin-containing mastocyte granules are stained pink and red by safranin, while those that do not contain heparin are stained blue by alcian blue. May-Grünwald–Giemsa staining, a type of Romanowsky stain, colors the cytoplasm of mast cells dark blue, and the granules red. It can be used to reveal mucosal mast cells. In 1958 Russian histologist M.G.
For Ajax, Edgar Davids the first penalty taker's shot was saved by Peruzzi. The next two players scored, those being Litmanen and Arnold Scholten. Their final penalty taken by Sonny Silooy was also saved. Jugović's goal was the decisive penalty that gave Juventus its second title in the competition; Juventus won by a score of 4–2.
Research in Italy suggests that healthy centenarians have high levels of both vitamin A and vitamin E and that this seems to be important in causing their extreme longevity. Other research contradicts this, however, and has found that this theory does not apply to centenarians from Sardinia, for whom other factors probably play a more important role. A preliminary study carried out in Poland showed that, in comparison with young healthy female adults, centenarians living in Upper Silesia had significantly higher red blood cell glutathione reductase and catalase activities, although serum levels of vitamin E were not significantly higher. Researchers in Denmark have also found that centenarians exhibit a high activity of glutathione reductase in red blood cells. In this study, the centenarians having the best cognitive and physical functional capacity tended to have the highest activity of this enzyme. Additional research shows that people whose parents became centenarians have a higher number of naïve B cells. It is known that the children of parents who have a long life are also more likely to reach older age, but it is not clear why, although inherited genes are believed to play an important role. A variation in the gene FOXO3A is known to have a positive effect on the life expectancy of humans, and is found much more often in people living to 100 and beyond – moreover, this appears to be true worldwide. Men and women who are 100 or older tend to have extroverted personalities, according to Thomas T.
Sources: en.wikipedia.org
In situ leaching or in situ recovery refers to the mining technique of injecting lixiviant underground to dissolve ore and bringing the pregnant leach solution to surface for extraction. Commonly used in uranium mining but has also been used for copper mining.
Biko's given name "Bantu" means "people" in IsiXhosa; Biko interpreted this in terms of the saying "Umntu ngumntu ngabantu" ("a person is a person by means of other people"). As a child he was nicknamed "Goofy" and "Xwaku-Xwaku", the latter a reference to his unkempt appearance. He was raised in his family's Anglican Christian faith. In 1950, when Biko was four, his father fell ill, was hospitalised in St. Matthew's Hospital, Keiskammahoek, and died, making the family dependent on his mother's income. Biko spent two years at St. Andrews Primary School and four at Charles Morgan Higher Primary School, both in Ginsberg. Regarded as a particularly intelligent pupil, he was allowed to skip a year. In 1963 he transferred to the Forbes Grant Secondary School in the township. Biko excelled at maths and English and topped the class in his exams. In 1964 the Ginsberg community offered him a bursary to join his brother Khaya as a student at Lovedale, a prestigious boarding school in Alice, Eastern Cape. Within three months of Steve's arrival, Khaya was accused of having connections to Poqo, the armed wing of the Pan Africanist Congress (PAC), an African nationalist group which the government had banned. Both Khaya and Steve were arrested and interrogated by the police; the former was convicted, then acquitted on appeal. No clear evidence of Steve's connection to Poqo was presented, but he was expelled from Lovedale. Commenting later on this situation, he stated: "I began to develop an attitude which was much more directed at authority than at anything else.
== External links == "Neuromedin U Receptors". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2016-03-03. Retrieved 2007-10-25. Neuromedin+U+Receptor at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
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.