heptapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-11-30 and is reviewed periodically as new material appears.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, 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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
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.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
=== Pre-1900 === Early film (pre-1900) was dominated by the novelty of showing an event. Single-shot moments were captured on film, such as a train entering a station, a boat docking, or factory workers leaving work. These short films were called "actuality" films; the term "documentary" was not coined until 1926. Many of the first films, such as those made by Auguste and Louis Lumière, were a minute or less in length, due to technological limitations. Films showing many people (for example, leaving a factory) were often made for commercial reasons: the people being filmed were eager to see, for payment, the film showing them. One notable film clocked in at over an hour and a half, The Corbett-Fitzsimmons Fight. Using pioneering film-looping technology, Enoch J. Rector presented the entirety of a famous 1897 prize-fight on cinema screens across the United States. In May 1896, Bolesław Matuszewski recorded on film a few surgical operations in Warsaw and Saint Petersburg hospitals. In 1898, French surgeon Eugène-Louis Doyen invited Matuszewski and Clément Maurice to record his surgical operations. They started in Paris a series of surgical films sometime before July 1898. Until 1906, the year of his last film, Doyen recorded more than 60 operations. Doyen said that his first films taught him how to correct professional errors he had been unaware of.
=== 547th Grenadier Division === The division was created as the 547th Grenadier Division in Military District V (Stuttgart) as a so-called Sperrdivision ("blocking division") belonging to the 29th Aufstellungswelle ("Wave of formations"). It was scheduled to be formed on 11 July 1944, however, its actual formation took place on 27 July 1944. From August 1944, the division served with the 4th Army under Army Group Centre and fought in Lithuania. On 9 October 1944, the 547th Grenadier Division was redesignated as the 547th Volksgrenadier Division. The reorganization was intended to bring the unit up to the standard of a division belonging to the 32nd wave of formations.
Lemelson-MIT Prize (2014) – known as the "Oscar for inventors", for groundbreaking inventions and dedication to the next generation of scientists. Heinz Award for Technology (2015) – for groundbreaking inventions and advocacy for women in STEM fields. Othmer Gold Medal (2019) – from the Science History Institute. Several honorary doctorate degrees, including from the Icahn School of Medicine at Mount Sinai (2021), University of London Institute Cancer Research (2019), and Utrecht University in the Netherlands (2017). Bhatia has also been honored with:
=== Organ rejection === Immune responses to both organ rejection and severe bacterial infection can lead to similar symptoms such as swelling and fever that can make initial diagnosis difficult. To differentiate between acute rejection of an organ transplant and bacterial infections, plasma procalcitonin levels have been proposed as a potential diagnostic tool. Typically the levels of procalcitonin in the blood remain below 0.5 ng/mL in cases of acute organ rejection, which has been stated previously to be well below the 1 μg/mL typically seen in bacterial infection.
The Southern Rhodesian economy grew considerably during the war despite the concurrent rise of war expenditure to pay for the expansion of the military and the air training scheme. Expenditure on the war grew from £1,793,367 in the financial year 1940–41 to £5,334,701 in 1943–44—total Southern Rhodesian expenditure on the air training scheme was £11,215,522. These sums, while tiny compared to those incurred by larger nations, were enormous when scaled against the white population of less than 70,000 that accounted for most of the colony's economic output. Annual costs for the air training scheme alone far exceeded the pre-war national budget. Southern Rhodesia was then the second largest gold producer in the world, after South Africa. The colony's gold output had expanded greatly during the 1930s, and it remained the territory's main source of income during the war, though many extracting operations were diverted towards strategic minerals, most prominently chrome and asbestos. Southern Rhodesia became one of the two main sources of chrome for the Allies (South Africa was the other) and the world's third largest producer of asbestos after Canada and the Soviet Union. By the end of the war the mines at Shabani and Mashaba were turning out 1.5 million tonnes of asbestos a year, in addition to 600,000 tonnes of chrome. Gold output reached peak levels in 1941–42 and thereafter subsided. Southern Rhodesia also exported tungsten, mica and tin, and provided coal for the copper mines of Northern Rhodesia and the Congo.
Sources: en.wikipedia.org
Adipocytes, also known as lipocytes and fat cells, are the cells that primarily compose adipose tissue, specialized in storing energy as fat. Adipocytes are derived from mesenchymal stem cells which give rise to adipocytes through adipogenesis. In cell culture, adipocyte progenitors can also form osteoblasts, myocytes and other cell types. There are two types of adipose tissue, white adipose tissue (WAT) and brown adipose tissue (BAT), which are also known as white and brown fat, respectively, and comprise two types of fat cells.
=== Drugs === Chlorphenamine, a first-generation alkylamine antihistamine Creatine phosphate, a chemical used to store phosphates in the body Cyclophosphamide, a medication to suppress the immune system
Previously, UNAMA had reported that between 26 February and 16 March, at least 76 civilian were killed and 213 were injured in Afghanistan as result of armed clashes between Taliban forces and Pakistan armed forces. On the same day, Pakistani officials said that they had foiled an attempt by Taliban forces to attack a Pakistani border post in Khyber Pakhtunkhwa's Ghulam Khan Sector, killing 37 Taliban fighters and injuring 80 others. Furthermore, Pakistani officials stated that since the start of hostilities, 796 Afghan Taliban and TTP militants had been killed and more than 1,043 injured. They added that Pakistani forces had destroyed 286 check-posts, captured 44 others, destroyed 249 tanks, armored vehicles, and artillery guns, and targeted 81 locations across Afghanistan in air strikes. On 6 April, an Afghan media outlet, citing tribal elders and local residents, reported that Taliban forces had abandoned several border posts in Nuristan and Kunar following recent clashes with Pakistani forces. The abandoned positions were said to be located in the Bari Kot area of Nari district, as well as in parts of Bargi Matal and Kamdesh. According to the report, Taliban fighters who withdrew from the posts took shelter in village mosques. Some tribal elders from these area accuse the Taliban of failing to maintain security in the border areas and of spreading misinformation about their presence. They say that Taliban members travel by helicopter to district centres in order to create the impression that the group remains active in the region.
=== 1989 local government reforms === For many decades until the local government reforms of 1989, a borough with more than 20,000 people could be proclaimed a city. The boundaries of councils tended to follow the edge of the built-up area, so little distinction was made between the urban area and the local government area. New Zealand's local government structural arrangements were significantly reformed by the Local Government Commission in 1989 when approximately 700 councils and special purpose bodies were amalgamated to create 87 new local authorities. Regional councils were reduced in number from 20 to 13, territorial authorities (city/district councils) from 200 to 75, and special purpose bodies from over 400 to 7. The new district and city councils were generally much larger and most covered substantial areas of both urban and rural land. Many places that once had a city council were now being administered by a district council. As a result, the term "city" began to take on two meanings. City also came to be used in a less formal sense to describe major urban areas independent of local body boundaries. This informal usage is jealously guarded. Gisborne, for example, adamantly described itself as the first city in the world to see the new millennium. Gisborne is administered by a district council, but its status as a city is not generally disputed. Under current law, an urban area has to be at least 50,000 residents before it can be officially proclaimed as a city.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
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.