This is a working overview of Selank, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-26. Anything still debated is marked as such rather than presented as settled.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
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.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
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.
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.
According to his father, the loan spells were the making of his son's career, while Tottenham's former Director of Football Damien Comolli, who was dismissed in October 2008, believes Townsend succeeded in spite of the way Tottenham handled him.
=== Analogues === The closely related medication, methylnaltrexone (N-methylnaltrexone), is used to treat opioid-induced constipation but does not treat addiction as it does not cross the blood–brain barrier. Nalmefene (6-desoxy-6-methylenenaltrexone) is similar to naltrexone and is used for the same purposes as naltrexone. Naltrexone should not be confused with naloxone (N-allylnoroxymorphone), which is used in emergency cases of opioid overdose. Other opioid antagonists related to naltrexone include 6β-naltrexol (6β-hydroxynaltrexone), samidorphan (3-carboxamido-4-hydroxynaltrexone), β-funaltrexamine (naltrexone fumarate methyl ester), nalodeine (N-allylnorcodeine), nalorphine (N-allylnormorphine), and nalbuphine (N-cyclobutylmethyl-14-hydroxydihydronormorphine).
By increasing the temperature and pressure he forced the liquid into a supercritical fluid state where by dropping the pressure he could instantly gasify and remove the liquid inside the aerogel, avoiding damage to the delicate three-dimensional network. While this can be done with ethanol, the high temperatures and pressures lead to dangerous processing conditions. A safer, lower temperature and pressure method involves a solvent exchange. This is typically done by exchanging the initial aqueous pore liquid for a CO2-miscible liquid such as ethanol or acetone, then onto liquid carbon dioxide, and then bringing the carbon dioxide above its critical point. A variant on this process involves the direct injection of supercritical carbon dioxide into the pressure vessel containing the aerogel. The result of either process exchanges the initial liquid from the gel with carbon dioxide, without allowing the gel structure to collapse or lose volume.
Sources: en.wikipedia.org
Unlike spectroscopic methods, X-ray crystallography always allows for unambiguous structure determination and provides precise bond angles and lengths totally unavailable through spectroscopy. It is often used in physical organic chemistry to provide an absolute molecular configuration and is an important tool in improving the synthesis of a pure enantiomeric substance. It is also the only way to identify the position and bonding of elements that lack an NMR active nucleus such as oxygen. Indeed, before x-ray structural determination methods were made available in the early 20th century all organic structures were entirely conjectural: tetrahedral carbon, for example, was only confirmed by the crystal structure of diamond, and the delocalized structure of benzene was confirmed by the crystal structure of hexamethylbenzene. While crystallography provides organic chemists with highly satisfying data, it is not an everyday technique in organic chemistry because a perfect single crystal of a target compound must be grown. Only complex molecules, for which NMR data cannot be unambiguously interpreted, require this technique. In the example below, the structure of the host–guest complex would have been quite difficult to solve without a single crystal structure: there are no protons on the fullerene, and with no covalent bonds between the two halves of the organic complex spectroscopy alone was unable to prove the hypothesized structure.
The two substrates of this enzyme are (R)-3-hydroxybutyric acid and oxidised nicotinamide adenine dinucleotide (NAD+}. Its products are acetoacetic acid, reducad NADH, and a proton. This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. This enzyme participates in the synthesis and degradation of ketone bodies and the metabolism of butyric acid.
Toxoid vaccines are made from inactivated toxic compounds that cause illness rather than the microorganism. Examples of toxoid-based vaccines include tetanus and diphtheria. Not all toxoids are for microorganisms; for example, Crotalus atrox toxoid is used to vaccinate dogs against rattlesnake bites.
Under traditional terminology, the American kestrel is the smallest raptor in the Americas, though the South American spot-winged falconet is almost as small. The American kestrel is sexually dimorphic, although there is some overlap in plumage coloration between the sexes. The bird ranges from 22 to 31 cm (8.7 to 12.2 in) in length with a wingspan of 51–61 cm (20–24 in). The female kestrel is larger than the male, though less so than larger falcons, being typically about 10% to 15% larger within a subspecies. The more northern subspecies tend to larger sizes (northern hemisphere), with a large northern female being about twice the size of a small southern male. The male typically weighs 80–143 g (2.8–5.0 oz), and the female 86–165 g (3.0–5.8 oz). In standard measurements, the wing bone is 16–21 cm (6.3–8.3 in) long, the tail is 11–15 cm (4.3–5.9 in) and the tarsus is 3.2–4 cm (1.3–1.6 in). Physically, American kestrels are leaner and less muscular than larger falcons. The pectoral flight muscles of the American kestrel make up only about 12% of its body weight, as compared to about 20% for the strongest flying falcons such as the peregrine falcon. The wings are moderately long, fairly narrow, and taper to a point. Their less muscular body type is adapted to energy-conserving ambush hunting, rather than spending large amounts of energy-consuming time on the wing and getting into long tail-chases of bird prey. For their size, they have strong talons and beaks, and can swiftly dispatch prey.
Sources: en.wikipedia.org
The beta sheet (β-sheet, also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet. A β-strand is a stretch of polypeptide chain typically 3 to 10 amino acids long with backbone in an extended conformation. The supramolecular association of β-sheets has been implicated in the formation of the fibrils and protein aggregates observed in amyloidosis, Alzheimer's disease and other proteinopathies.
Mangum co-founded the Melbourne Research Unit for Facial Disorders at the Royal Children's Hospital and the University of Melbourne. He was Peter Doherty Fellow and Head of the Translational Proteomics Laboratory from 2014 to 2020, contributing to fields including dental enamel research, cerebrospinal fluid biomarker discovery, and metastatic cancer resistance mechanisms. He has published over 30 peer-reviewed articles and is listed as inventor on more than 20 patents internationally. Mangum co-founded Incisive Technologies in 2012 and led the development of its lead product, BlueCheck™, from initial research through to GMP manufacturing and market clearance. He was Chief Executive Officer (2018–2021) and Chief Scientific Officer (2018–2024), overseeing regulatory strategy, manufacturing scale-up, clinical trials, and scientific marketing. He designed the company's ISO 13485–certified Melbourne facility and led successful funding rounds totalling over AUD $20 million.
Many studies have found that tolerance develops to the anticonvulsant properties of clonazepam with chronic use, which limits its long-term effectiveness as an anticonvulsant. Abrupt or over-rapid withdrawal from clonazepam may result in the development of the benzodiazepine withdrawal syndrome, causing psychosis characterised by dysphoric manifestations, irritability, aggressiveness, anxiety, and hallucinations. Sudden withdrawal may also induce the potentially life-threatening condition, status epilepticus. Anti-epileptic drugs, benzodiazepines such as clonazepam in particular, should be reduced in dose slowly and gradually when discontinuing the drug to mitigate withdrawal effects. Carbamazepine has been tested in the treatment of clonazepam withdrawal but was found to be ineffective in preventing clonazepam withdrawal-induced status epilepticus from occurring.
== External links == Antivenom Index, a joint project of the Association of Zoos and Aquariums and the American Association of Poison Control Centers which helps locate rare antivenoms Venom Response Program of the Miami-Dade Fire Rescue service
They rose up to defend the rights and status that they had received as Indians from the colonial power, and that the criollo republic threatened to liquidate. On the other hand, it has been pointed out that he gave instructions to the army of Greater Colombia, during the Peruvian War of Independence, to carry out looting and other kinds of harassment against the Peruvian population, under the excuse that in times of war it was necessary to act dictatorially, giving extraordinary powers to the militia, and showing indifference to serious cases of corruption, of which Bolívar, instead of executing them, would rather have been in charge of distributing said loot (to avoid conflict between his caudillos) of the Peruvian victims to the looting of their properties. Only in the province of Lambayeque, which was not one of the richest, the amount of 500,000 pesos was extracted in 1824, by quotas and confiscations. In addition to the fact that he came to dismiss Peruvians like Andrés de los Reyes, due to his protests that he gave for Bolívar's orders to loot churches. The discomfort caused by the looting of the Colombians made the indigenous guerrilla Ninavilca exclaim from the four winds that the Colombians were "una chusma de ladrones" [a mob of thieves] who plundered Peruvian resources, and once the conflict ended they did not become more popular, generating an Anti-Colombian (included anti-venezolan) feeling in Peru. "Not only did Bolívar transfer his dictatorial power to Heres.
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
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.