If you have been reading about Intranasal delivery and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-12-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 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.
| 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 |
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
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.
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.
==== Return to Frankfurt University ==== Upon his return, Adorno helped shape the political culture of West Germany. Until his death in 1969, twenty years after his return, Adorno contributed to the intellectual foundations of the Federal Republic as a professor at the University of Frankfurt am Main, critic of the vogue enjoyed by Heideggerian philosophy, partisan of critical sociology, and teacher of music at the Darmstadt International Summer Courses for New Music. Adorno resumed his teaching duties at the university soon after his arrival, with seminars on "Kant's Transcendental Dialectic," aesthetics, Hegel, "Contemporary Problems in the Theory of Knowledge," and "The Concept of Knowledge." Adorno's surprise at his students' passionate interest in intellectual matters did not, however, blind him to continuing problems within Germany: The literary climate was dominated by writers who had remained in Germany during Hitler's rule, the government re-employed people who had been active in the Nazi apparatus, and people were generally loath to own up to their own collaboration or the guilt they thus incurred. Instead, the ruined city of Frankfurt continued as if nothing had happened, holding on to ideas of the true, the beautiful, and the good despite the atrocities, hanging on to a culture that had itself been lost in rubble or killed off in the concentration camps. All the enthusiasm Adorno's students showed for intellectual matters could not erase the suspicion that, in the words of Max Frisch, culture had become an "alibi" for the absence of political consciousness.
The glutathione reductase is conserved between all kingdoms. In bacteria, yeasts, and animals, one glutathione reductase gene is found; however, in plant genomes, two GR genes are encoded. Drosophila and trypanosomes do not have any GR at all. In these organisms, glutathione reduction is performed by either the thioredoxin or the trypanothione system, respectively.
Ubiquitin signaling relies on the diversity of ubiquitin tags for the specificity of its message. A protein can be tagged with a single ubiquitin molecule (monoubiquitylation), or variety of different chains of ubiquitin molecules (polyubiquitylation). E3 ubiquitin ligases catalyze polyubiquitination events much in the same way as the single ubiquitylation mechanism, using instead a lysine residue from a ubiquitin molecule currently attached to substrate protein to attack the C-terminus of a new ubiquitin molecule. For example, a common 4-ubiquitin tag, linked through the lysine at position 48 (K48) recruits the tagged protein to the proteasome, and subsequent degradation. However, all seven of the ubiquitin lysine residues (K6, K11, K27, K29, K33, K48, and K63), as well as the N-terminal methionine are used in chains in vivo. Monoubiquitination has been linked to membrane protein endocytosis pathways. For example, phosphorylation of the Tyrosine at position 1045 in the Epidermal Growth Factor Receptor (EGFR) can recruit the RING type E3 ligase c-Cbl, via an SH2 domain. C-Cbl monoubiquitylates EGFR, signaling for its internalization and trafficking to the lysosome. Monoubiquitination also can regulate cytosolic protein localization. For example, the E3 ligase MDM2 ubiquitylates p53 either for degradation (K48 polyubiquitin chain), or for nuclear export (monoubiquitylation). These events occur in a concentration dependent fashion, suggesting that modulating E3 ligase concentration is a cellular regulatory strategy for controlling protein homeostasis and localization.
Sources: en.wikipedia.org
=== Lethality === Calciseptine is toxic in low doses. No specific data are available on the toxicity of calciseptine in humans. However, the LD50 values for mice have been determined and can be found in the table below:
== Environment benefit == Hemp protein is gaining attention in the context of its environment benefit. Hemp is reevaluated as a promising crop in the era of sustainable development goals (SDG) due to its sustainable growth characteristics and versatile industrial usability. The entire hemp plant—its leaves, stalks, roots, and seeds—can be used, reducing waste. The stalk is used for fiber production, the leaves/roots for medicine, and seeds for oil and protein. Hemp has a short cropping period and requires less pesticide or water compared to cotton, a representative fiber material and food plant, that makes hemp a sustainable choice for cultivation.
Ever since the discovery that monoclonal antibodies could be generated, scientists have targeted the creation of fully human products to reduce the side effects of humanised or chimeric antibodies. Several successful approaches have been proposed: transgenic mice, phage display and single B cell cloning.
=== Halogens === Elements such as chlorine, iodine, fluorine, and bromine are nonmetallic in nature and constitute the halogen family. Each of these halogens have a different antimicrobial effect that is influenced by various factors such as pH, temperature, contact time, and type of microorganism. Chlorine and iodine are the two most commonly used antimicrobials. Chlorine is extensively used as a disinfectant in the water treatment plants, drug, and food industries. In wastewater treatment plants, chlorine is widely used as a disinfectant. It oxidizes soluble contaminants and kills bacteria and viruses. It is also highly effective against bacterial spores. The mode of action is by breaking the bonds present in these microorganisms. When a bacterial enzyme comes in contact with a compound containing chlorine, the hydrogen atom in that molecule gets displaced and is replaced with chlorine. This in turn changes the enzyme function which ultimately leads to the death of the bacterium. Iodine is most commonly used for sterilization and wound cleaning. The three major antimicrobial compounds containing iodine are alcohol-iodine solution, an aqueous solution of iodine, and iodophors. Iodophors are more bactericidal and are used as antiseptics as they are less irritating when applied to the skin. Bacterial spores on the other hand cannot be killed by iodine, but they can be inhibited by iodophors. The growth of microorganisms is inhibited when iodine penetrates into the cells and oxidizes proteins, genetic material, and fatty acids.
Sources: en.wikipedia.org
==== Satiety ==== As a peptide hormone, CCK mediates satiety by acting on the CCK receptors distributed widely throughout the central nervous system. The mechanism for hunger suppression is thought to be a decrease in the rate of gastric emptying. CCK also has stimulatory effects on the vagus nerve, effects that can be inhibited by capsaicin. The stimulatory effects of CCK oppose those of ghrelin, which has been shown to inhibit the vagus nerve. The effects of CCK vary between individuals. For example, in rats, CCK administration significantly reduces hunger in adult males, but is slightly less effective in younger subjects, and even slightly less effective in females. The hunger-suppressive effects of CCK also are reduced in obese rats.
==== Name and country change, convicted of drug smuggling ==== On 10 October 1991, Olofsson was released, changed his name to Daniel Demuynck, and moved to the Belgian countryside, 80 km outside Brussels. In July 1996, Olofsson was arrested outside a bank in Oslo when the police thought he was preparing a robbery. He was released after 24 hours. On a stormy November night, he was rescued by a sea rescue helicopter off the coast of Halland after his wooden boat was smashed against the rocks. A few weeks later, he was taken into custody for drunk driving in Stockholm. On 15 April 1998, he was arrested in Tenerife as the head of drug smuggling after being wanted internationally via Interpol for several months. He was extradited to Denmark and after a high-profile trial in Frederikssund, he was sentenced in 1999 to fourteen years in prison for smuggling 49 kilos of amphetamine into Denmark. It was then the most severe punishment for drug offenses ever handed out in Danish legal history. While in Denmark, he was held in the isolation ward at Vestre Prison in Copenhagen. He was released on parole on 9 May 2005.
In the 2013 gubernatorial election, Republican Chris Christie received 64.3% of the vote (1,412 cast), ahead of Democrat Barbara Buono with 34.9% (766 votes), and other candidates with 0.9% (19 votes), among the 2,259 ballots cast by the borough's 4,949 registered voters (62 ballots were spoiled), for a turnout of 45.6%. In the 2009 gubernatorial election, Republican Chris Christie received 1,213 votes (49.5% vs. 45.8% countywide), ahead of Democrat Jon Corzine with 1,106 votes (45.2% vs. 48.0%), Independent Chris Daggett with 99 votes (4.0% vs. 4.7%) and other candidates with 8 votes (0.3% vs. 0.5%), among the 2,449 ballots cast by the borough's 4,975 registered voters, yielding a 49.2% turnout (vs. 50.0% in the county).
In a flowing plasma afterglow, ions are formed in a flow of inert gas, typically helium or argon. Reagents are added downstream to create ion products and study reaction rates. Flowing-afterglow mass spectrometry is used for trace gas analysis for organic compounds.
=== SophiA === Funded by the European Commission- Horizon 2020 and European Green Deal Duration: 4 years (October 2021-September 2025) Objective: SophiA enables African countries to pursue sustainable pathways of development through a low-carbon, climate-resilient and green growth trajectory, leapfrogging fossil fuels and high global warming potential refrigerant technologies.
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.
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.