Everything below concerns GABA-A modulation. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-20. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Principal proposed target | GABA-A receptor complex | Hypothesis derived mainly from animal pharmacology |
| Common behavioral assay | Elevated plus maze | Rodent test for anxiety-like behavior |
| Reported molecular marker | Hippocampal BDNF expression | Measured by immunoassay or mRNA quantification |
| Typical dosing route | Intranasal | Chosen to reduce first-pass metabolism |
| Reported plasma half-life | Minutes | Based on limited peptide stability data |
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.
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.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
Pulmonary hypertension has been gaining recognition as a complication of chronic hereditary and acquired hemolysis. Free hemoglobin released during hemolysis inactivates the vasodilator nitric oxide (NO). Hemolysis also releases arginase that depletes L-arginine, the substrate needed for NO synthesis. This reduces NO-dependent vasodilation and induces platelet activation, thrombin generation, procoagulant factors and tissue factor activation, contributing to the formation of thrombosis. This can lead to esophageal spasm and dysphagia, abdominal pain, erectile dysfunction, systemic hypertension, decreased organ perfusion, promotion of inflammation and coagulation, and thrombosis. Chronic hemolysis may also lead to endothelial dysfunction, heightened endothelin-1-mediated responses and vasculopathy. The release of heme leads to the production of bilirubin and depletion of plasma proteins, such as albumin, haptoglobin, and hemopexin, which may lead to jaundice. It may also lead to increased levels of the heme breakdown product stercobilin in the stool. Splenectomy of those with hemolytic disorders appears to increase risk of developing pulmonary thrombosis. Complications may also arise from the increased workload for the kidney as it secretes erythropoietin to stimulate the bone marrow to produce more reticulocytes (red blood cell precursors) to compensate for the loss of red blood cells due to hemolysis.
On 23 September, the IDF conducted over 1,600 strikes in Lebanon, killing at least 558 people and injuring more than 1,835 others including children, women and paramedics according to the Lebanese Health Ministry. Hezbollah fired about 240 rockets into Israel, the West Bank, and Golan Heights, injuring five people. It first fired 35 rockets into northern Israel targeting IDF bases and warehouses, lightly injuring a man in the Lower Galilee. It later fired around 80 rockets, targeting several locations including Ariel and Karnei Shomron in the occupied West Bank and Haifa. The group targeted IDF bases and Rafael Advanced Defense Systems facilities. Ali Karaki, the commander of Hezbollah's Southern Front, was targeted in an Israeli airstrike in Dahieh. Hezbollah said that he survived the attack. A Hamas field commander was killed in an Israeli airstrike in southern Lebanon.
=== Industry === Industrial source waste can contain alpha, beta, neutron or gamma emitters. Gamma emitters are used in radiography while neutron emitting sources are used in a range of applications, such as oil well logging.
Iodine in food is absorbed by the body and preferentially concentrated in the thyroid where it is needed for the functioning of that gland. When 131I is present in high levels in the environment from radioactive fallout, it can be absorbed through contaminated food, and will also accumulate in the thyroid. As it decays, it may cause damage to the thyroid. The primary risk from exposure to 131I is an increased risk of radiation-induced cancer in later life. Other risks include the possibility of non-cancerous growths and thyroiditis. The risk of thyroid cancer in later life appears to diminish with increasing age at time of exposure. Most risk estimates are based on studies in which radiation exposures occurred in children or teenagers. When adults are exposed, it has been difficult for epidemiologists to detect a statistically significant difference in the rates of thyroid disease above that of a similar but otherwise-unexposed group. The risk can be mitigated by taking iodine supplements, raising the total amount of iodine in the body and, therefore, reducing uptake and retention in the face and chest and lowering the relative proportion of radioactive iodine. However, such supplements were not consistently distributed to the population living nearest to the Chernobyl nuclear power plant after the disaster, though they were widely distributed to children in Poland. Within the US, the highest 131I fallout doses occurred during the 1950s and early 1960s to children having consumed fresh milk from sources contaminated as the result of above-ground testing of nuclear weapons.
Sources: en.wikipedia.org
In the brain, zinc is stored in specific synaptic vesicles by glutamatergic neurons and can modulate neuronal excitability. It plays a key role in synaptic plasticity and so in learning. Zinc homeostasis also plays a critical role in the functional regulation of the central nervous system. Dysregulation of zinc homeostasis in the central nervous system that results in excessive synaptic zinc concentrations is believed to induce neurotoxicity through mitochondrial oxidative stress (e.g., by disrupting certain enzymes involved in the electron transport chain, including complex I, complex III, and α-ketoglutarate dehydrogenase), the dysregulation of calcium homeostasis, glutamatergic neuronal excitotoxicity, and interference with intraneuronal signal transduction. L- and D-histidine facilitate brain zinc uptake. SLC30A3 is the primary zinc transporter involved in cerebral zinc homeostasis.
112—single emergency 101—the Fire Service and the Ministry of Emergency Situations 102—the police 103—ambulance 104—gas emergency Moscow's Emergency Medical Service (EMS) is the second most efficient among the world's megacities, according to the consultancy PwC in a study called "Analysis of EMS Efficiency in Megacities of the World".
== Further reading == Kielley WW, Bradley LB (1954). "Glutathione thiolesterase". J. Biol. Chem. 206 (1): 327–33. doi:10.1016/S0021-9258(18)71321-5. PMID 13130552. Murata, Kousaku; Sato, Nobuyuki; Rhee, Hae-ik; Watanabe, Kunihiko; Kimura, Akira (1987). "Purification and Characterization of Glutathione Thiol Esterase from Saccharomyces cerevisiae". Agricultural and Biological Chemistry. 51 (7): 1901–1907. doi:10.1080/00021369.1987.10868321. Uotila, Lasse (1979). "Glutathione thiol esterases of human red blood cells". Biochimica et Biophysica Acta (BBA) - Protein Structure. 580 (2): 277–288. doi:10.1016/0005-2795(79)90140-5. PMID 93000.
==== MeSH E05.393.661 – nucleic acid hybridization ==== MeSH E05.393.661.124 – branched dna signal amplification assay MeSH E05.393.661.250 – heteroduplex analysis MeSH E05.393.661.475 – in situ hybridization MeSH E05.393.661.475.350 – in situ hybridization, fluorescence MeSH E05.393.661.475.350.125 – chromosome painting MeSH E05.393.661.475.680 – primed in situ labeling MeSH E05.393.661.640 – oligonucleotide array sequence analysis
== History == Electron-capture dissociation was developed by Roman Zubarev and Neil Kelleher while in Fred McLafferty's lab at Cornell University. Irradiation of melittin 4+ ions and ubiquitin 10+ ions (trapped in FT-MS cell) by laser pulses not only resulted in peculiar c', z fragmentation but also charge reduction. It was suggested that if FT cell is modified to trap cations and electrons simultaneously, secondary electrons emitted by UV photons increases the charge reduction effect and c′, z• fragmentation. Replacing UV laser with EI source led to the development of this new technique.
Sources: en.wikipedia.org
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.
Behavioral endpoints include time spent in open arms of the elevated plus maze and avoidance latencies. Biochemical endpoints include BDNF concentration, cytokine levels, and monoamine metabolite ratios in brain tissue.
Most published studies are small, originate from a limited number of laboratories, and lack independent replication. Dose-response relationships, measured brain exposure, and long-term outcomes are not well characterized.
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.