If you have been reading about Tuftsin 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.
Updated 2026-04-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Free peptide form |
| Molecular mass | About 751.9 Da | Calculated average mass |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form TKPRPGP |
| Structural basis | Tuftsin analogue | Extended version of a natural tetrapeptide |
| Development origin | Russian Academy of Sciences | Work carried out from the 1980s onward |
Once dissolved, the peptide is markedly less stable than the dry powder. Aqueous solutions are subject to backbone hydrolysis and to microbial growth when they are handled without sterile technique. Buffered solutions near neutral pH are common for short-term laboratory work, while acidic conditions are sometimes used to improve solubility. Analytical laboratories generally prepare working solutions fresh rather than storing them, and a residual water film left in a reopened vial can seed degradation even when the container appears dry.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
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.
metabolome The complete set of small-molecule chemical compounds within a cell, organelle, or any other biological sample, including both endogenous molecules (e.g. individual amino acids and nucleotides, fatty acids, organic acids, amines, simple sugars, vitamins, antibiotics, etc.) and exogenous molecules (e.g. drugs, toxins, environmental contaminants, and other xenobiotics).
The Goths were expanding towards the Lower Danube from the 230s, forcing the native peoples to flee to the Roman Empire or to accept their suzerainty. The Goths' rule ended abruptly when the Huns invaded their territory in 376, causing new waves of migrations. The Huns forced the remnants of the local population into submission, but their empire collapsed in 454. The Gepids took possession of the former Dacia province. Place names that are of Slavic origin abound in Romania, indicating that a significant Slavic-speaking population lived in the territory. The first Slavic groups settled in Moldavia and Wallachia in the 6th century, in Transylvania around 600. The nomadic Avars defeated the Gepids and established a powerful empire around 570. The Bulgars, who also came from the European Pontic steppe, occupied the Lower Danube region in 680.
=== Collagen === Collagen is the most abundant protein in mammals and is an essential molecule in the formation of bones, skin and other connective tissue. Different types of collagen have been found in all multicellular organisms, including sponges. It has been found that sponges do have a gene sequence coding for collagen type IV which is a diagnostic feature of the basal lamina. It has also been found that 29 types of collagen have been found to exist in humans. This vast group can further be divided into several families according to their primary structures and supramolecular organization. Among the many types of collagens, only the fibrillar and the basement membrane (type IV) collagens have been found in the sponges and cnidarians, which are the two earliest branching metazoan lineages. Studies have focused on the origin of fibrillar collagen molecules. In Sponges, there exist three clades of fibrillar molecules, A, B and C. It is proposed that only the B clade fibrillar collagens preserved their characteristic modular structure from sponge to human. In mammals, the fibrillar collagens involved in the formation of cross-striated fibrils are types I–III, V, and XI. Type II and type XI collagens compose the fibrils present in cartilage. These can be distinguished from collagens located in non-cartilaginous tissues, which include type I, III, and V collagens.
Sources: en.wikipedia.org
=== Academics and Islamic scholars === Muhammad Ibn Muhammad Al-Fulani Al-Kishwani – prominent mathematician in the early 1700s from Katsina Usman dan Fodio (1754–1817) – Islamic scholar, revolutionary from Sokoto, founder and spiritual leader of the Sokoto Caliphate. Abdullahi dan Fodio (1766–1829) – scholar, jurist, pioneer, Grand Vizier of Sokoto and first Emir of Gwandu (r. 1812–1828). Nana Asma'u – princess, poet, Islamic scholar and daughter of Usman dan Fodio. Muhammed Bello (1781–1837) – the first sultan of Sokoto. Abd al-Qadir dan Tafa (1804–1864) – described as the "most learned scholar of his time" in the Sokoto Caliphate who specialized in philosophy (Falsafa) Abu Bakr Atiku (1782–1842) – second sultan of the Sokoto Caliphate, reigning from October 1837 until November 1842. Muhammadu Junaidu – former grand vizier of Sokoto, historian, writer Hayatu ibn Sa'id - great-grandson of Usman dan Fodio, Mahdist leader who attempted to conquer Bornu and The Sokoto Caliphate. Muhammad Bukhari bin Uthman - military commander, scholar and poet. Son Of Usman dan Fodio. Modibbo Adama (1786–1847) – first Laamiɗo and founder of Fombina (Adamawa emirate) which covered parts of Nigeria, Cameroon and Chad. Modibbo Raji – influential 19th century Islamic scholar who is generally regarded as the founder of the Islamic scholarly tradition in Adamawa;Wazir(vizier) in the Gwandu Emirate of the Sokoto Caliphate Muhammad Auwal Albani Zaria - prominent Islamic scholar and reformer. Isa Ali Pantami - Islamic scholar, former Minister of Communications and Digital economy.
Adenylylation, more commonly known as AMPylation, is a process in which an adenosine monophosphate (AMP) molecule is covalently attached to the amino acid side chain of a protein. This covalent addition of AMP to a hydroxyl side chain of the protein is a post-translational modification. Adenylylation involves a phosphodiester bond between a hydroxyl group of the molecule undergoing adenylylation, and the phosphate group of the adenosine monophosphate nucleotide (i.e. adenylic acid). Enzymes that are capable of catalyzing this process are called AMPylators.
Eplerenone is a newer drug that was developed as a spironolactone analog with reduced adverse effects. In addition to the y-lactone ring and the substituent on C-7, eplerenone has a 9α,11α-epoxy group. This group is believed to be the reason why eplerenone has a 20-40-fold lower affinity for the mineralocorticoid receptor than spironolactone. Despite the nonsteroidal nature of finerenone which yields a different lipophilicity and polarity profile for this compound, finerenone's affinity toward mineralocorticoid receptors is equal to that of spironolactone and 500 times that of eplerenone, hinting that the steroidal core component of most antimineralocorticoids is not essential for mineralocorticoid receptor affinity.
David Russell, consumer advocate, chief executive of Consumer NZ (1990–2007) (born 1942). 30 September – Nigel Latta, clinical psychologist and television host (Beyond the Darklands, The Politically Incorrect Parenting Show, Nigel Latta Blows Stuff Up) (born 1967).
Sources: en.wikipedia.org
In Switzerland, a maximum radiation exposure of 1 mSv per year and a maximum of 5 mSv per year for the patient's relatives may not be exceeded. After discharge following radioiodine therapy, a maximum dose rate of 5 μSv per hour at a distance of 1 meter is permitted, which corresponds to a residual activity of approximately 150 MBq. In the event of early discharge, the supervisory authority must be notified up to a dose rate of 17.5 μSv/h; above 17.5 μSv/h, permission must be obtained. If the patient is transferred to another ward, the responsible radiation protection officer must ensure that appropriate radiation protection measures are taken there, e.g. that a temporary control area is set up.
=== Inhibition of ACTH production === Corticotropes contain glucocorticoid receptors (GRs) and corticosteroid-binding globulin (CBG, or transcortin). GR is a nuclear receptor that inhibits transcription of ACTH via a negative glucocorticoid recognition element (GRE) that binds cortisol on POMC DNA, but generally transcortin binds glucocorticoids (including cortisol, cortisone, deoxycortisone, and aldosterone) with high affinity and prevents this inhibition. Tonic inhibition of corticotropes requires high concentrations of glucocorticoids, exceeding CBG capacity. This causes ACTH secretion to be vulnerable to inhibition in patients taking glucocorticoids for medical purposes such as treatment of autoimmune disease or as an anti-transplant-rejection medication.
=== Major depressive disorder === The mechanistic rationale for KOR antagonism in major depressive disorder (MDD) derives from the observation that chronic stress and depression are associated with higher activity of the KOR system. KOR activation suppresses dopamine release and prevents dopamine rebound after stress exposure, thereby leading to anhedonia and depressive phenotypes. KOR antagonists reverse this pathway by disinhibiting dopaminergic tone and restoring reward sensitivity. KOR-mediated upregulation of pro-inflammatory signaling in microglia likely drives the depression pathophysiology, and antagonism may provide benefits. The claustrum-prelimbic cortex circuit operates via dynorphin and KOR signaling to modulate cognitive and affective functions. Buprenorphine/samidorphan (ALKS-5461) displayed antidepressant efficacy in randomized controlled trials as an adjunctive therapy and has shown durable effects with a favorable safety profile including low abuse potential and minimal withdrawal symptoms. A phase 2 study demonstrated significant reduction of depressive symptoms and improvement in anhedonia when aticaprant was added to existing antidepressant therapy. A phase 3 clinical trials (KOASTAL-1 and additional studies) of navacaprant failed to achieve statistically significant superiority over placebo across the broader MDD population, with its development discontinued for this purpose in early 2025.
=== Extrapulmonary === Very rarely, the primary site for small-cell carcinoma is outside of the lungs and pleural space; in these cases, it is referred to as extrapulmonary small-cell carcinoma (EPSCC). Outside of the respiratory tract, small-cell carcinoma can appear in the cervix, prostate, liver, pancreas, gastrointestinal tract, or bladder. It is estimated to account for 1,000 new cases a year in the U.S. Histologically similar to small-cell lung cancer, therapies for small-cell lung cancer are usually used to treat EPSCC. First-line treatment is usually with cisplatin and etoposide. In Japan, first-line treatment is shifting to irinotecan and cisplatin. When the primary site is in the skin, it is referred to as a Merkel-cell carcinoma.
In cases of chronic arsenic exposure, the nitric oxide levels are depleted, due to the superoxide reactions. The enzyme NO synthase (NOS) uses L-arginine to form nitric oxide, but this enzyme is inhibited by monomethylated arsenic (III) compounds.
Sources: en.wikipedia.org
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.
The core four residues correspond to tuftsin, which occurs naturally as part of immunoglobulin G. The full seven-residue sequence, however, is not a known endogenous peptide. It is a laboratory-designed analogue intended to combine tuftsin-like activity with greater resistance to breakdown.
No single receptor has been confirmed as the primary target. Reports describe involvement of the GABAergic system, interference with enkephalin degradation, and shifts in neurotrophic factor expression. Because these observations come from different models and assays, they have not yet been integrated into one accepted mechanism.
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.