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 2026-06-27 and is reviewed periodically as new material appears.
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.
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.
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.
| 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 |
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
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.
=== Fluorescent detection === Fluorescence spectroscopy is one of the most common droplet detection techniques. It provides a rapid response, and, for applicable analytes, it has a strong signal. The use of fluorescence spectroscopy in microfluidics follows a similar format to most other fluorescent analytical techniques. A light source is used to excite analyte molecules in the sample, after which the analyte fluoresces, and the fluorescence response is the measured output. Cameras can be used to capture the fluorescence signal of the droplets, and filters are often used to filter out scattered excitation light. In microfluidic droplet detection, the experimental setup of a fluorescence instrument can vary greatly. A common setup in fluorescent droplet detection is with the use of an epifluorescence microscope. This sometimes utilizes a confocal geometry, which can vary depending on experimental needs. For example, Jeffries et al. reported success with exploring an orthogonal confocal geometry, as opposed to a standard epi geometry. However, other setups for fluorescence detection have been explored, as epifluorescence microscopes can be expensive and difficult to upkeep. Cole et al. have proposed and tested an experimental setup with fiber optics to conduct fluorescence analysis of microfluidic droplets. Fluorescence detection of droplets has a number of advantages. First, it can accommodate a large and fast throughput. Analysis of thousands of samples can be conducted in a short period of time, which is advantageous for the analysis of a large number of samples.
Calcitonin gene-related peptide 1 (CGRP1), also called calcitonin-related polypeptide alpha, is a hormone that in humans is encoded by the CALCA gene. This calcitonin gene-related peptide triggers vasodilation (relaxation/widening of blood vessels), and also signals to platelets.
The Germans and Japanese were relatively successful in recruiting combat forces from Indian prisoners of war. These forces were known as the Tiger Legion and the Indian National Army (INA). Indian nationalist leader Subhas Chandra Bose led the 40,000-strong INA. From a total of about 55,000 Indians taken prisoner in Malaya and Singapore in February 1942, about 30,000 joined the INA, which fought Allied forces in the Burma Campaign. Others became guards at Japanese POW camps. The recruitment was the brainchild of Major Fujiwara Iwaichi who mentions in his memoirs that Captain Mohan Singh Deb, who surrendered after the Battle of Jitra became the founder of the INA.Some Indian Army personnel resisted recruitment and remained POWs. An unknown number captured in Malaya and Singapore were taken to Japanese-occupied areas of New Guinea as forced labour. Many of these men suffered severe hardships and brutality, similar to that experienced by other prisoners of Japan during the Second World War. About 6,000 of them survived until they were liberated by Australian or US forces, in 1943–45. During the later stages of the Second World War, from the fall of Singapore and the ending of ABDACOM in early 1942 until the formation of the South East Asia Command (SEAC) in August 1943, some American and Chinese units were placed under British military command.
Sources: en.wikipedia.org
The third phase follows at 3 to 5 days, and is marked by complications of massive liver necrosis leading to fulminant liver failure with complications of coagulation defects, low blood sugar, kidney failure, hepatic encephalopathy, brain swelling, sepsis, multiple organ failure, and death. If the third phase is survived, the liver necrosis runs its course, and liver and kidney function typically return to normal in a few weeks. The severity of paracetamol toxicity varies depending on the dose and whether appropriate treatment is received.
The most common adverse effects of Captopril, skin rash and loss of taste, are the same as caused by mercapto-containing penicillamine. Therefore, a group of researchers aimed at finding potent, selective ACE inhibitors that would not contain a mercapto (SH) function and would have a weaker chelating function. They returned to work with carboxyl compounds and started working with substituted N-carboxymethyl-dipeptides as a general structure (R-CHCOOH-A1-A2). According to previous research they assumed that cyclic imino acids would result in good potency if substituted on the carboxyl terminus of the dipeptide. Therefore, substituting A2 with proline gave good results. They also noted that according to the enzyme's specificity imino acids in the position next to the carboxyl terminus would not give a potent compound. By substituting R and A1 groups with hydrophobic and basic residues would give a potent compound. By substituting –NH in the general structure resulted in loss of potency which is consistent to the enzyme's need for a –NH in corresponding position on the substrates. The results were 2 active inhibitors: Enalaprilat and Lisinopril. These compounds both have phenylalanine in R position which occupies the S1 groove in the enzyme. The result was thus these two new, potent tripeptide analogues with zinc-coordinating carboxyl group: Enalaprilat and Lisinopril.
=== Proposed re-engined versions === In the 1980s, there were moves to fit the Il-86 with RB211-22 engines. Designated Il-86V (second use of this designation), this would have had a range of over 9,000 km (4,860 nmi) and/or increased payload. Another 450-seater Il-86V powered by RB211-524G engines was also projected. Amid the disintegration of the Soviet economy, these versions did not progress. In 1991, there were moves to fit the Il-86 with Franco-American CFM56-5C2 engines. Finances precluded progress. In 1995, International Aero Engines offered the V2500 engine to five Il-86 operators with proposals to re-engine 25 aircraft. The offer was not taken up.
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.
It is a seven-amino-acid peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, produced by chemical synthesis rather than extracted from biological tissue. Its design is based on tuftsin, a natural immunomodulatory tetrapeptide. The C-terminal Pro-Gly-Pro segment is a common stabilising motif in short regulatory peptides.