Everything below concerns Heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-08. 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, 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.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
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 |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
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.
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.
CPA is available in the form of oral tablets alone (higher-dose; 10 mg, 50 mg, 100 mg) or in combination with ethinylestradiol or estradiol valerate (low-dose; 1 or 2 mg CPA) and in the form of ampoules for intramuscular injection (higher-dose; 100 mg/mL, 300 mg/3 mL; brand name Androcur Depot). The higher-dose formulations are used to treat prostate cancer and certain other androgen-related indications while the low-dose formulations which also have an estrogen are used as combined birth control pills and are used in menopausal hormone therapy for the treatment of menopausal symptoms.
Taxifolin (5,7,3',4'-flavan-on-ol), also known as dihydroquercetin, belongs to the subclass flavanonols in the flavonoids, which in turn is a class of polyphenols. It is extracted from plants such as Siberian larch and milk thistle.
== Career == Borchers headed the University of Victoria–Genome BC Proteomics Centre from 2006 and from 2006 to 2019 was a professor in the Department of Biochemistry and Microbiology at the University of Victoria. At Victoria he held the Don and Eleanor Rix BC Leadership Chair in Biomedical and Environmental Proteomics. He subsequently moved to McGill University, where he now directs the Segal Cancer Proteomics Centre and the Warren Y. Soper Clinical Proteomics Centre. He is a co-editor-in-chief of the journal Expert Review of Proteomics, published by Taylor & Francis. Beyond his own laboratory, Borchers has taken on leadership roles in the proteomics community: he served on the Technology/Standards Committee of the Human Proteome Organization (HUPO), co-leading a work track on the harmonization of proteomics and quantification methods at the 2012 HUPO Proteomics Standards Initiative workshop, and later chaired the 14th HUPO World Congress, held in Vancouver in 2015. He was also one of three founding directors of the Canadian National Proteomics Network (CNPN), together with Guy Poirier and Ronald Beavis, chairing the 2008 workshop that established the network's organizing committee and later serving as its president.
That is how this entire mass of suffering originates.The Mahahatthipadopama-sutta (M 28) contains another short explanation of dependent origination:these five grasping aggregates are indeed dependently originated. The desire, adherence, attraction, and attachment for these five grasping aggregates is the origin of suffering. Giving up and getting rid of desire and greed for these five grasping aggregates is the cessation of suffering.
Sources: en.wikipedia.org
== External links == "FDA Drug Safety Communication: FDA urges caution about withholding opioid addiction medications from patients taking benzodiazepines or CNS depressants: careful medication management can reduce risks". U.S. Food and Drug Administration (FDA). 7 January 2021. Archived from the original on 14 September 2019.
lists each of the twenty possible outcomes for an amino acid — it can mutate into one of the 19 other amino acids, or remain unchanged. Since the non-diagonal entries listing the probabilities of each of the 19 mutations are known, and the sum of the probabilities of these twenty outcomes must be 1, this last probability can be calculated by
1985–1987 – 1.1 L (1,071 cc) E1, 2 barrel, 8-valve, 55 PS (40 kW; 54 hp) / 59 lb⋅ft (80 N⋅m) 1985–1987 – 1.3 L (1,296 cc) E3, 2 barrel, 8-valve, 68 PS (50 kW; 67 hp) / 71 lb⋅ft (96 N⋅m) – 60 PS (44 kW; 59 hp) in some markets, 65 PS in Switzerland 1987–1989 – 1.3 L (1,323 cc) B3, 2 barrel, 8-valve, 66 PS (49 kW; 65 hp) / 74 lb⋅ft (100 N⋅m) 1987–1989 – 1.5 L (1,498 cc) B5, 2 barrel, 12-valve, 73 PS (54 kW; 72 hp) / 81 lb⋅ft (110 N⋅m) 1985–1989 – 1.6 L (1,597 cc) B6, 8-valve, 85 PS (63 kW; 84 hp) / 90 lb⋅ft (122 N⋅m) 1985–1989 – 1.6 L (1,597 cc) B6T, turbo, 16-valve, 140 PS (103 kW; 138 hp) / 138 lb⋅ft (187 N⋅m) 1988–1991 – 2.0 L (1,998 cc) FE-SOHC, EFi, 8-valve, 118 PS (87 kW; 116 hp) / 131 lb⋅ft (178 N⋅m) (South Africa only) 1991–1994 – 2.0 L (1,998 cc) FE-DOHC, EFi, 16-valve, 146 PS (107 kW; 144 hp) / 136 lb⋅ft (184 N⋅m) (South Africa only) 1986–199? – 1.7 L (1,720 cc) PN, diesel, 8-valve, 57 PS (42 kW; 56 hp)
Sources: en.wikipedia.org
=== Heart attacks after use of Vioxx === In 1999, the U.S. Food and Drug Administration (FDA) approved Vioxx (known generically as rofecoxib), a Merck product for treating arthritis. Vioxx was designed as a selective inhibitor of the enzyme cyclooxygenase-2. Such compounds were expected to cause less gastrointestinal bleeding than older anti-inflammatory drugs such as naproxen, which were associated with 20,000 hospitalizations and 2000 deaths each year. Vioxx became one of the most prescribed drugs in history. Thereafter, studies by Merck and by others found an increased risk of heart attack associated with Vioxx use when compared with naproxen. Merck adjusted the labeling of Vioxx to reflect possible cardiovascular risks in 2002. On September 23, 2004, Merck received information about results from a clinical trial it was conducting that included findings of increased risk of heart attacks among Vioxx users who had been using the medication for over eighteen months. On September 28, 2004, Merck notified the FDA that it was voluntarily withdrawing Vioxx from the market, and it publicly announced the withdrawal on September 30. An analysis for the period 1999–2004, based on U.S. Medical Expenditure Survey data, reported that Vioxx was associated with 46,783 heart attacks in the US, and along with the other popular COX-2 inhibitor Celebrex, an estimated 26,603 deaths from both. About 50,000 people sued Merck, claiming they or their family members had suffered medical problems such as heart attacks or strokes after taking Vioxx.
Because of cardiolipin's unique structure, a change in pH and the presence of divalent cations can induce a structural change. CL shows a great variety of forms of aggregates. It is found that in the presence of Ca2+ or other divalent cations, CL can be induced to have a lamellar-to-hexagonal (La-HII) phase transition. And it is believed to have a close connection with membrane fusion.
This property is what gives DNA its semi-conservative nature where one strand of new DNA is from an original parent strand. Although the structure of DNA showed how inheritance works, it was still not known how DNA influences the behavior of cells. In the following years, scientists tried to understand how DNA controls the process of protein production. It was discovered that the cell uses DNA as a template to create matching messenger RNA, molecules with nucleotides very similar to DNA. The nucleotide sequence of a messenger RNA is used to create an amino acid sequence in protein; this translation between nucleotide sequences and amino acid sequences is known as the genetic code. With the newfound molecular understanding of inheritance came an explosion of research. A notable theory arose from Tomoko Ohta in 1973 with her amendment to the neutral theory of molecular evolution through publishing the nearly neutral theory of molecular evolution. In this theory, Ohta stressed the importance of natural selection and the environment to the rate at which genetic evolution occurs. One important development was chain-termination DNA sequencing in 1977 by Frederick Sanger. This technology allows scientists to read the nucleotide sequence of a DNA molecule. In 1983, Kary Banks Mullis developed the polymerase chain reaction, providing a quick way to isolate and amplify a specific section of DNA from a mixture. The efforts of the Human Genome Project, Department of Energy, NIH, and parallel private efforts by Celera Genomics led to the sequencing of the human genome in 2003.
On 31 October 1899, General Sir Redvers Henry Buller, a much-respected commander, arrived in South Africa with the Army Corps, made up of the 1st, 2nd and 3rd divisions. Buller originally intended an offensive straight up the railway leading from Cape Town through Bloemfontein to Pretoria. Finding on arrival that British troops were under siege, he split his army corps into detachments to relieve the besieged garrisons. One division, led by Lieutenant General Lord Methuen, was to follow the Western Railway to the north and relieve Kimberley and Mafeking. A smaller force of 3,000, led by Major General William Gatacre, was to push north towards the railway junction at Stormberg and secure the Cape Midlands District from Boer raids and rebellions by Boer inhabitants. Buller led the major part of the army corps to relieve Ladysmith to the east. The initial results of this offensive were mixed, with Methuen winning bloody skirmishes in the Battle of Belmont on 23 November, the Battle of Graspan on 25 November, and at a larger engagement, the Battle of Modder River, on 28 November resulting in British losses of 71 dead and over 400 wounded. British commanders had been trained on the lessons of the Crimean War and were adept at battalion and regimental set pieces, with columns manoeuvring in jungles, deserts and mountainous regions. What British generals failed to comprehend was the impact of destructive fire from trench positions and the mobility of cavalry raids.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
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.