This is a working overview of Regulatory peptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-08 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
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.
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.
Tsukihi Aragami (荒神 月燈, Aragami Tsukihi) Special Agent of National Security. She's the captain of Kaguya's security. She was only appointed to this role temporarily, but she has deep respect and affection for him. She grew up in a family devoted to the gods.
Day of Defeat is a class-based multiplayer first-person shooter video game set in the European theatre of World War II on the Western front. Originally a modification of the 1998 game Half-Life, the rights of the modification were purchased by Valve and released as a full retail title in 2003. Set in the midst of World War II, Day of Defeat includes no single-player campaign, with focus left only on the game's multiplayer aspects. The game favors teamwork and features objective-based gameplay in combination with its system of classes. Maps are primarily made up of narrow paths, all of which typically lead to a few key locations. An official remake of the game, Day of Defeat: Source, was released by Valve in 2005.
==== Aqueous solutions ==== Aqueous solutions are solutions of a compound with water. In contrast to other formulations, such as oil solutions, aqueous suspensions, and emulsions, aqueous solutions of estradiol and estradiol esters by intramuscular injection are not depot injections. Instead, they are rapidly absorbed and eliminated, analogously to intravenous injections of estradiol and estradiol esters. The durations of aqueous solutions of estradiol and estradiol esters by intramuscular injection are measured in hours.
Both pathways rely on 5α-reductase, but in the androgen backdoor pathway, this enzyme acts on C21 steroids (pregnanes), initiating a series of chemical reactions that eventually lead to dihydrotestosterone production. In contrast, in the canonical pathway, 5α-reductase targets the 4,5-double bond in testosterone, producing dihydrotestosterone directly. The backdoor pathway was initially described as a biosynthetic route where 5α-reduction of 17α-hydroxyprogesterone ultimately leads to dihydrotestosterone. Since then, several other pathways have been discovered that lead to 11-oxygenated androgens which are also physiologically significant.
Sources: en.wikipedia.org
Research into the cause of the disease began in 1868, when grape growers in Roquemaure, near Pujaut, asked the agricultural society in Montpellier for help. The society appointed a committee including botanist Jules Émile Planchon, local grower Felix Sahut, and the society's president, Gaston Bazille. Sahut soon noticed that the roots of dying vines were infested with "lice" which were sucking sap from the plants. The committee named the new insect Rhizaphis vastatrix. Planchon consulted French entomologists Victor Antoine Signoret and Jules Lichtenstein (Planchon's brother-in-law). Signoret suggested renaming the insect Phylloxera vastatrix, due to its similarity to Phylloxera quercus, which afflicted oak leaves. In 1869, English entomologist John Obadiah Westwood suggested that an insect that had afflicted grape leaves in England circa 1863 was the same insect afflicting grape vines' roots in France. Also in 1869, Lichtenstein suggested that the French insect was an American "vine louse" that had been identified in 1855 by the American entomologist Asa Fitch, which he had named Pemphigus vitifoliae. However, there was a problem with these suggestions: French grape lice were known to infest only a vine's roots, whereas American grape lice were known to infest only its leaves. The British-born American entomologist Charles Valentine Riley had been following news of the outbreak in France.
==== Tests for pigments ==== In October 1978 a team of scientists affiliated with STURP took 32 samples from the surface of the Shroud, using adhesive tape. Of those samples, 18 were taken from areas of the Shroud that showed a body or blood image, while 14 were taken from non-image areas. The chemical microscopist Walter McCrone, a leading expert in the forensic authentication of historical documents and works of art, examined the tapes using polarized light microscopy and other physical and chemical techniques. McCrone concluded that the Shroud's body image had been painted with a dilute pigment of red ochre (a form of iron oxide) in a collagen tempera (i.e., gelatin) medium, using a technique similar to the grisaille employed in the 14th century by Simone Martini and other European artists. McCrone also found that the "bloodstains" in the image had been highlighted with vermilion (a bright red pigment made from mercury sulfide), also in a collagen tempera medium. McCrone reported that no actual blood was present in the samples taken from the Shroud. Other members of STURP rejected McCrone's conclusions and concluded, based on their own examination of the Shroud and the tape samples, that the image on the Shroud could not be explained by the presence of pigments. Mark Anderson, who was working for McCrone, analyzed the Shroud samples. In his book, chemist Raymond Rogers states that Anderson, who was McCrone's Raman microscopy expert, concluded that the samples acted as organic material when he subjected them to the laser.
Delta-beta thalassemia is autosomal recessive disorder, which means both parents are affected and two copies of the gene must be present. A carrier gets a normal gene to produce hemoglobin A, from one parent and the other parent supplies a gene which makes no hemoglobin A. Delta-beta thalassemia is considered rare. Delta-beta-thalassemia is caused by deletions of the entire delta and beta genes sequences and only gamma-globin and HbF are formed. Rarely, non-deletional forms have been reported. When two delta0 mutations are inherited, no hemoglobin A2 (alpha2, delta2) are formed. This is innocuous because only 2-3% of normal adult hemoglobin is hemoglobin A2. The individual will have normal hematological parameters (erythrocyte count, total hemoglobin, mean corpuscular volume). The delta-beta thalassemia demonstrates one mutation is at the +69 position.
Sources: en.wikipedia.org
==== Aerospace ==== In April 1972 Heseltine was promoted to be minister for aerospace, a minister of state rather than a Cabinet minister but effectively running his own department within the Department of Trade and Industry, another of Heath's new mega ministries. The department had been given major new powers by the 1972 Industry Act. Later in the year Peter Walker was appointed Secretary of State for Trade and Industry, making him Heseltine's boss once again. Heseltine appointed Cecil Parkinson, whom he had met on an accountancy course in the mid-1950s, as his Parliamentary Private Secretary, ostensibly on the grounds that he knew even less about aerospace than he did. Parkinson was impressed by Heseltine's vigour and his insistence that civil servants produce results for him quickly, later writing in his memoirs (1992) "in his constructive and deliberate unreasonableness he reminds me in many ways of Mrs Thatcher". Heseltine arguably did not make aerospace policy any more interventionist than it already was. One of Heseltine's main jobs was to sell Concorde, which was difficult because of its cost and limited range (it could fly from New York to London or Paris, but not the short extra distance to Rome or Frankfurt) and capacity (a quarter that of a Boeing 747). It had been initiated by Macmillan in 1962 as an Anglo-French project to try to get Britain into the EEC, although by the early 1970s Heath was already broaching cancellation with President Pompidou.
As an isolate - through the process of wet fractionation which produces a high protein concentration As a concentrate - through the process of dry fractionation which produces a low protein concentration In textured form, which is when it is used in food products as a substitute for other products, such as meat alternatives Pea protein has low allergenicity and high nutritional value. It is common as a source of protein in vegan and vegetarian food, and in protein supplement products.
=== Plasma cortisol concentration === Resting plasma cortisol may be slightly elevated in affected horses, but is commonly within normal limits or below normal. Additionally, elevations may occur secondary to stress, concurrent disease, and due to individual variation. Therefore, resting cortisol levels alone are not adequate to diagnose or rule out the presence of PPID.
Huntington's disease has autosomal dominant inheritance, meaning that an affected individual typically inherits one copy of the gene with an expanded trinucleotide repeat (the mutant allele) from an affected parent. Since the penetrance of the mutation is very high, those who have a mutated copy of the gene will have the disease. In this type of inheritance pattern, each offspring of an affected individual has a 50% risk of inheriting the mutant allele and developing the disease (see figure). This probability is sex-independent since the huntingtin gene is not located on the X or Y chromosomes. Trinucleotide CAG repeats numbering over 28 are unstable during replication, and this instability increases with the number of repeats present. This usually leads to new expansions as generations pass (dynamic mutations) instead of reproducing an exact copy of the trinucleotide repeat. This causes the number of repeats to change in successive generations, such that an unaffected parent with an "intermediate" number of repeats (28–35), or "reduced penetrance" (36–40), may pass on a copy of the gene with an increase in the number of repeats that produces fully penetrant HD. The earlier age of onset and greater severity of disease in successive generations due to increases in the number of repeats is known as genetic anticipation. Instability is greater in spermatogenesis than oogenesis; maternally inherited alleles are usually of a similar repeat length, whereas paternally inherited ones have a higher chance of increasing in length.
Sources: en.wikipedia.org
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.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.