Everything below concerns elevated plus maze. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-18. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
| 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 |
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Cytochrome c belongs to class I of the c-type cytochrome family and contains a characteristic CXXCH (cysteine-any-any-cysteine-histidine) amino acid motif that binds heme. This motif is located towards the N-terminus of the peptide chain and contains a histidine as the 5th ligand of the heme iron. The 6th ligand is provided by a methionine residue found towards the C-terminus. The protein backbone is folded into five α-helices that are numbered α1-α5 from N-terminus to C-terminus. Helices α3, α4 and α5 are referred to as 50s, 60s and 70s helices, respectively, when referring to mitochondrial cytochrome c.
Krebs (1900–1981), German-British biochemist, Nobel Prize in Physiology or Medicine (1953)for work on metabolic cycles Harold Kroto (1939–2016), English chemist, 1996 Nobel Prize in Chemistry for discovery of fullerenes Richard Kuhn (1900–1967), 1938 Nobel Prize in Chemistry for work on carotenoids and vitamins Eugenia Kumacheva (PhD 1986), Ukrainian-Canadian chemist with work on fundamental and applied polymers science, nanotechnology, microfluidics, and interface chemistry Theodore Kuwana, (1931–2022), American chemist, founder of the field of spectroelectrochemistry
Nausea: ~ 11%; 1% severe nausea and 2% discontinued treatment due to nausea. Diarrhea: ~ 8%; 2% severe diarrhea and 1% of patients discontinued treatment due to diarrhea. Less common adverse reactions (<1%): fecal incontinence, blood potassium decreased. For subjects with irritable bowel syndrome with constipation:
It has also been argued that such testing potentially implicates the Fifth Amendment privilege against self-incrimination, the right to due process (including the prohibition against gathering evidence in a manner that shocks the conscience or constitutes outrageous government conduct), and the prohibition against unreasonable searches and seizures contained in the Fourth Amendment. According to Henriksson, the anti-drug appeals of the Reagan administration "created an environment in which many employers felt compelled to implement drug testing programs because failure to do so might be perceived as condoning drug use. This fear was easily exploited by aggressive marketing and sales forces, who often overstated the value of testing and painted a bleak picture of the consequences of failing to use the drug testing product or service being offered." On March 10, 1986, the Commission on Organized Crime asked all U.S. companies to test employees for drug use. By 1987, nearly 25% of the Fortune 500 companies used drug tests. According to an uncontrolled self-report study done by DATIA and Society for Human Resource Management in 2012 (sample of 6,000 randomly selected human resource professionals), human resource professionals reported the following results after implementing a drug testing program: 19% of companies reported a subjective increase in employee productivity, 16% reported a decrease in employee turnover (8% reported an increase), and unspecified percentages reported decreases in absenteeism and improvement of workers' compensation incidence rates.
==== Metabolism ==== A steady-state plasma level of dofetilide is achieved in 2–3 days. 80% of dofetilide is excreted by the kidneys, so the dose of dofetilide should be adjusted in individuals with chronic kidney disease, based on creatinine clearance. In the kidneys, dofetilide is eliminated via cation exchange (secretion). Agents that interfere with the renal cation exchange system, such as verapamil, cimetidine, hydrochlorothiazide, itraconazole, ketoconazole, prochlorperazine, and trimethoprim should not be administered to individuals taking dofetilide. About 20 percent of dofetilide is metabolized in the liver via the CYP3A4 isoenzyme of the cytochrome P450 enzyme system. Drugs that interfere with the activity of the CYP3A4 isoenzyme can increase serum dofetilide levels. If the renal cation exchange system is interfered with (as with the medications listed above), a larger percentage of dofetilide is cleared via the CYP3A4 isoenzyme system.
Sources: en.wikipedia.org
While it is usually considered that the driver has the responsibility when collisions occur, vehicle can also contribute to collisions, up to 3% to 5% of crashes. Two kinds of programs exist: new car assessment program for new cars, and vehicle inspections for other ones. A New Car Assessment Program is a government or institutional car safety program tasked with evaluating new car designs for performance against various safety threats. Two well known NCAP are United States New Car Assessment Program since 1978 and European New Car Assessment Programme since 1997.
Alternative splicing is one of the most important components that show functional complexity of genome. Modified splicing has significant effect on the phenotype that is relevance to disease or drug metabolism. A change in splicing can be caused by modifying any of the components of the splicing machinery such as splice sites or splice enhancers or silencers. Modification in the alternative splicing site can lead to a different protein form which will show a different function. Humans use an estimated 100,000 different proteins or more, so some genes must be capable of coding for a lot more than just one protein. Alternative splicing occurs more frequently than was previously thought and can be hard to control; genes may produce tens of thousands of different transcripts, necessitating a new gene model for each alternative splice.
Some studies have shown that principal antitubercular action of PAS occurs via poisoning of folate metabolism. Specifically, 4-aminosalicylic acid is incorporated into the folate pathway in place of the correct 4-aminobenzoic acid (PABA) by dihydropteroate synthase (DHPS) to generate hydroxyl-dihydropteroate (HO-H2Pte; 2'-hydroxy-7,8-dihydropteroate). This product is then used by dihydrofolate synthase (DHFS) to make a hydroxyl-dihydrofolate (HO-H2PteGlu) antimetabolite. HO-H2PteGlu competes with dihydrofolate for the binding site of dihydrofolate reductase (DHFR) and blocks the enzymatic activity.
Michel Gondry was working on a film adaptation in early 2011, with Steve Golin and Steve Zaillian producing. In 2014, however, Gondry told French outlet Telerama (via Jeux Actu) that he was no longer working on the project and explained: "The book is brilliant, but it's good as a literary work. Having tried to adapt it with several screenwriters, ... at the moment I don't feel up to doing it. It doesn't have the dramatic structure that would make it a good film. I received a script that disheartened me a bit, and that was it. It was a dream, but in life you can't always have what you want."
Sources: en.wikipedia.org
Most metabolic processes have a specific and narrow range of pH where operation is possible, multiple regulatory systems are in place to maintain homeostasis. Fluctuations away from optimal operating pH can slow or impair reactions and possibly cause damage to cellular structures or proteins. To maintain homeostasis the body may excrete excess acid or base through the urine, via gas exchange in the lungs, or buffer it in the blood. The bicarbonate buffering system of blood plasma effectively holds a steady pH and helps to hold extracellular pH around 7.35. The kidneys are responsible for the majority of acid-base regulation but can excrete urine no lower than a pH of 5. This means that a 330mL can of cola, for example, usually ranging in pH from 2.8 to 3.2, would need to be diluted 100 fold before being excreted. Instead of producing 33L of urine from one can of cola, the body relies on buffer to neutralize the acid. Systemic acidosis can be the result of multiple factors, not just diet. Anaerobic exercise, diabetes, AIDS, aging, menopause, inflammation, infections, tumours, and other wounds and fractures all contribute to acidosis. Blood has an average pH of 7.40 but interstitial fluid can vary. Interstitial pH of the skin, for example, is ~7.1. There is no data available for bone.
Another similar characterization concerns the exradii ra, rb, rc, and rd in the same four triangles (the four excircles are each tangent to one side of the quadrilateral and the extensions of its diagonals). A quadrilateral is tangential if and only if
Growth factor receptor-bound protein 14 is a protein that in humans is encoded by the GRB14 gene. The product of this gene belongs to a small family of adapter proteins that are known to interact with a number of receptor tyrosine kinases and signaling molecules. This gene encodes a growth factor receptor-binding protein that interacts with insulin receptors and insulin-like growth-factor receptors. This protein likely has an inhibitory effect on receptor tyrosine kinase signaling and, in particular, on insulin receptor signaling. This gene may play a role in signaling pathways that regulate growth and metabolism. Transcript variants have been reported for this gene, but their full-length natures have not been determined to date.
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 peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.