Everything below concerns GABA-A receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-12-29. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
| 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 |
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
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.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
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.
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.
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.
=== Appearance === Semen normally has a whitish-gray colour. It tends to get a yellowish tint as a man ages. Semen colour is also influenced by the food we eat: foods that are high in sulfur, such as garlic, may result in a man producing yellow semen. Presence of blood in semen (hematospermia) leads to a brownish or red coloured ejaculate. Hematospermia is a rare condition. Brown semen is a result of infection, inflammation, trauma or tumor in the urological components such as the urethra, epididymis and seminal vesicles Semen that has a deep yellow colour or is greenish in appearance may be due to medication.Other causes of unusual semen colour include sexually transmitted infections such as gonorrhea and chlamydia, genital surgery and injury to the male sex organs.
=== Structure === The dihydroxyquinoline core is composed of (1S)-5-amino-2,3-dihydro- 8,9-dihydroxy-1H-pyrimido[1,2-a]quinoline-1-carboxylic acid. This portion of the molecule is invariant amongst all observed pyoverdine molecules. The core is modified by the addition of an amino acid chain composed of 6-14 amino acids. The chain of amino acids is built onto the chromophore core, and is synthesized via non-ribosomal peptide synthesis. As is common for non-ribsosomally synthesized peptides, pyoverdine frequently includes D-form amino acids and non-standard amino acids, such as N-5-formyl-N-5-hydroxyornithine. The peptide chain may also be partially (or completely) cyclized. This peptide chain provides the other four aspects of the hexadentate interaction, usually through hydroxamate and/or hydroxycarboxylate groups. This portion of the molecule is also crucial for interaction with the ferripyoverdine receptor (FpvA) that allows ferripyoverdine to be imported into the cell. The peptide chain produced by a given strain of Pseudomonas is currently thought to be invariant. Little is known about the particular function or importance of the ketoacid side chain, but it is well known that pyoverdine molecules with different ketoacids (congeners) co-exist. Ketoacids that have been observed include succinate/succinamide, glutamate, glutarate, malate/malamide, and α-ketoglutarate.
Its ability to regulate adhesion, migration, proliferation, immune regulation, and ECM remodeling makes it an important contributor in normal tissue development, homeostasis, and repair while also having a part in pathological processes such as fibrosis, inflammation, and cancer. The diverse roles of ITGA1 highlight its importance as both a mediator of tissue homeostasis and a potential target for diseases driven by abnormal cell-ECM interactions.
These receptors modulate the release of other neurochemicals such as serotonin in the case of MOR agonists, and acetylcholine in the case of D2. These changes can account for the physical and psychological remission of the pathology of addiction. The longer effects of KOR agonism (30 minutes or greater) have been linked to KOR-dependent stress-induced potentiation and reinstatement of drug seeking. It is hypothesized that these behaviors are mediated by KOR-dependent modulation of dopamine, serotonin, or norepinephrine and/or via activation of downstream signal transduction pathways. Of significant note, while KOR activation blocks many of the behavioral and neurochemical responses elicited by drugs of abuse as stated above. These results are indicative of the KOR induced negative affective states counteracting the rewarding effects of drugs of abuse. Implicating the KOR/dynorphin system as an anti-reward system, supported by the role of KOR signaling and stress, mediating both stress-induced potentiation of drug reward and stress-induced reinstatement of seeking behavior. This in turn addresses what was thought to be paradoxical above. That is, rather, KOR signaling is activated/upregulated by stress, drugs of abuse and agonist administration - resulting in negative affective state. As such drug addiction is maintained by avoidance of negative affective states in stress, craving, and drug withdrawal.
Kief is a powder, rich in trichomes, that can be sifted from the leaves, flowers and fruits of cannabis plants and either consumed in powder form or compressed to produce cakes of hashish. The term derives from colloquial Arabic كيف kēf/kīf, meaning pleasure.
Sources: en.wikipedia.org
=== La–Lem === Marc Lacroix (b. 1963). Belgian biochemist at the Institut Jules Bordet (Brussels), who specializes in breast cancer biology, metastasis and therapy. Keith Laidler (1916–2003). British-Canadian chemist and biochemist at the University of Ottawa. Expert on chemical and enzyme kinetics. Fellow of the Royal Society of Canada. Henry Lardy (1917–2010). American biochemist at the University of Wisconsin, noted for work on metabolism. Member Natl. Acad. Sci. USA. Michel Lazdunski (b. 1938). French biochemist and neuroscientist at Sophia Antipolis. Known especially for work on ion channels. Full Member of the French Academy of Sciences. Jack Legge (1917–1996). Australian biochemist known for his work on blood pigment metabolism and participation in mustard gas trials on Australian Defence Force volunteers during WW2. Albert L. Lehninger (1917–1986). American biochemist at the University of Wisconsin. He discovered, with Eugene P. Kennedy, that mitochondria are the site of oxidative phosphorylation in eukaryotes. Author of several influential texts, including The Mitochondrion, Bioenergetics and Biochemistry. Member Natl. Acad. Sci. USA. Luis Federico Leloir FRS (foreign associate) (1906–1987). Argentinian biochemist at the Fundación Instituto Campomar (Buenos Aires) who worked on sugar nucleotides, carbohydrate metabolism, and renal hypertension. Nobel Prize for Chemistry (1970). Rudi Lemberg FRS (1896–1975). German-Australian biochemist, director of the Kolling Institute of Medical Research from 1935 to 1972. Known for porphyrin research.
== Research directions == Research is being done to identify the proteins cleaved by calpain-3. Gene therapy is being studied to replace the function of the calpain-3. Injection of plasmids containing CAPN3 into mouse models resulted in increased levels of calpain-3.
Biography at the Biographical Directory of the United States Congress Financial information (federal office) at the Federal Election Commission Appearances on C-SPAN Booknotes interview with Hastert on Speaker: Lessons from 40 Years in Coaching and Politics (August 15, 2004) Transcript (PDF) of Hastert sentencing hearing (April 27, 2015), made available by the Chicago Tribune Official biography from Dickstein Shapiro (this profile was removed from the firm's website after Hastert resigned following the announcement of the indictment, but the Internet Archive preserved a copy of the profile as it appeared on March 25, 2015) NewsMeat list of contributors to Hastert's campaigns Hastert Exhibit from Wheaton College Archives and Special Collections; includes archival photo gallery
Each Equip issue discussed the state of a particular games platform, looking back on significant releases with the benefit of hindsight and outlining future developments. For example, the GameCube issue featured lengthy retrospectives on The Legend of Zelda: The Wind Waker and Animal Crossing, plus a feature on upcoming titles that would use the GameCube – Game Boy Advance link cable. 'Specials issue ten: "Retro: The Collector's Series" This final edition in the Retro series reprinted all of the "Collector's Series" of articles from the main magazine. Each feature focused on a specific video game console of yesteryear and examined its history and the collectors market surrounding its rare or collectable games. Unusually for Edge, the majority of these articles were written by one video games journalist: Simon Parkin, a long-time freelance contributor to the magazine. "Edge presents FILE Volume 1 - Issues 1-12: The birth of a new generation" (2006) "Edge presents FILE Volume 2 - Issues 13-24: The new generation shows its strength" (2007) "Edge presents FILE Volume 3 - Issues 25-36: Videogame culture enters a new era" (2007)
== History == Rosiglitazone was approved by the US FDA in 1999 and by the EMA in 2000; the EMA however required two postmarketing studies on longterm adverse effects, one for chronic heart failure and the other for cardiovascular effects.
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.
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.