Neurotrophic signalling is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-11-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
=== Extraction thimbles === Extraction thimbles are rod-shape filter paper often used in soxhlet extractors or atomized extractors. It is ideal for very sensitive detection, the performance depends on the thickness of inner diameter. Also, it is usually used in areas of food control and environmental monitoring.
The human heart is situated in the mediastinum, at the level of thoracic vertebrae T5–T8. A double-membraned sac called the pericardium surrounds the heart and attaches to the mediastinum. The back surface of the heart lies near the vertebral column, and the front surface, known as the sternocostal surface, sits behind the sternum and rib cartilages. The upper part of the heart is the attachment point for several large blood vessels—the venae cavae, aorta and pulmonary trunk. The upper part of the heart is located at the level of the third costal cartilage. The lower tip of the heart, the apex, lies to the left of the sternum (8 to 9 cm from the midsternal line) between the junction of the fourth and fifth ribs near their articulation with the costal cartilages. The largest part of the heart is usually slightly offset to the left side of the chest (levocardia). In a rare congenital disorder (dextrocardia) the heart is offset to the right side and is felt to be on the left because the left heart is stronger and larger, since it pumps to all body parts. Because the heart is between the lungs, the left lung is smaller than the right lung and has a cardiac notch in its border to accommodate the heart. The heart is cone-shaped, with its base positioned upwards and tapering down to the apex. An adult heart has a mass of 250–350 grams (9–12 oz). The heart is often described as the size of a fist: 12 cm (5 in) in length, 8 cm (3.5 in) wide, and 6 cm (2.5 in) in thickness, although this description is disputed, as the heart is likely to be slightly larger.
H2S. Very small amounts of H2S, SF6, and probably any other sulfur containing gases, cause immediate and complete deactivation of the catalyst. It is not possible to regenerate a poisoned catalyst that has been deactivated by sulfur, by treating with either oxygen or hydrogen. If sulfur containing gases are present in the sample, a switching valve should be used either to bypass the catalyst, or to back-flush the column to vent after elution of CO2. Air or O2. Reports of oxygen poisoning seem to be rather rumors than real facts. Small amounts of air through a catalyst will not kill it but anything over about 5 cc/min will cause an immediate and continual degradation of the catalyst. Unsaturated hydrocarbons. Samples of pure ethylene cause immediate, but partial, degradation of the catalyst, evidenced by slight tailing of CO and CO2 peaks. The effect of 2 or 3 samples might be tolerable, but since it is cumulative, such gases should be backflushed or bypassed. Low concentrations do not cause any degradation. Samples of pure acetylene affect the catalyst much more severely than does ethylene. Low concentrations have no effect. Probably some carbonization with high concentrations of unsaturates occurs, resulting in the deposit of soot on the catalyst surface. It is likely that aromatics would have the same effect. Other compounds. Water has no effect on the catalyst, as well as various Freons and NH3. Here again, with NH3, there is conflicting evidence from some users, who have seen a degradation after several injections, but other researchers were not able to confirm it.
The insulin-like growth factors (IGFs) are proteins with high sequence similarity to insulin. IGFs are part of a complex system that cells use to communicate with their physiologic environment. This complex system (often referred to as the IGF "axis") consists of two cell-surface receptors (IGF1R and IGF2R), two ligands (IGF-1 and IGF-2), a family of seven high-affinity IGF-binding proteins (IGFBP1 to IGFBP7), as well as associated IGFBP degrading enzymes, referred to collectively as proteases.
Sources: en.wikipedia.org
Le Havre Octeville Airport which is located 5 km (3 mi) north of Le Havre at the town of Octeville-sur-Mer and managed by CODAH. The airport does not have any scheduled services to or from Le Havre at this time. Currently, air travel is served by the nearest Caen–Carpiquet Airport which is located approximately 54 km away from Le Havre. The main destination is the Transport hub of Lyon. Many holiday destinations are offered each year (Tunisia, Balearic Islands, Portugal, Greece, Bulgaria, etc.) through local travel agencies that charter aircraft. There is also the Flying club Jean Maridor at the airport. The Channel maritime links with Portsmouth in southern England with P&O Ferries ended on 30 September 2005 to be taken over by LD Lines who had changed the configuration. Two services to Portsmouth are provided daily from the Terminal de la Citadelle until ceasing operations in 2014, the route has since been taken over by Brittany Ferries. It will cease in September 2026. The link to Ireland was moved to the port of Cherbourg. Crossing times to Portsmouth vary from five hours and thirty minutes to eight hours. Popular alternative routes going to areas close to Le Havre include Newhaven to Dieppe, and Poole to Cherbourg.
=== Post-translational modifications and cofactors === Phosphorylation of the N-terminus not only prevents MDM2 binding but also facilitates the recruitment of cofactors. Pin1 enhances conformational changes in p53, while p300 and PCAF acetylate the C-terminus, exposing the DNA-binding domain and enhancing transcriptional activation. Conversely, deacetylases such as Sirt1 and Sirt7 remove these modifications, suppressing apoptosis and promoting cell survival. Some oncogenes can also activate p53 indirectly by inhibiting MDM2.
IQSEC2: encodes an exchange factor for the Arf family of small GTP binding proteins, involved in the formation of secretory vesicles. TM4SF2: is a member of the 4 transmembrane domains family of proteins (tetraspanins, see TSPAN7). This gene is also associated with neuropsychiatric diseases such as Huntington's chorea. AP1S2: AP-1 complex subunit sigma-2. Adaptor protein complex 1 is found on the cytoplasmic face of vesicles located at the Golgi complex, where it mediates both the recruitment of clathrin to the membrane and the recognition of sorting signals within the cytosolic tails of transmembrane receptors. ACSL4: Long-chain-fatty-acid—CoA ligase 4 is an enzyme of the long-chain fatty-acid-coenzyme A ligase family. It converts free long-chain fatty acids into fatty acyl-CoA esters, and thereby play a key role in lipid biosynthesis and fatty acid degradation. This isozyme preferentially utilizes arachidonate as substrate. ZNF41: Zinc finger protein 41 is a likely zinc finger family transcription factor. DLG3: Disks large homolog 3, also named neuroendocrine-DLG or synapse-associated protein 102 (SAP-102). DLG3 is a member of the membrane-associated guanylate kinase (MAGUK) superfamily. FTSJ1: Transfert RNA methyltransferase 1 is a member of the S-adenosylmethionine-binding protein family. This nucleolar protein is involved in the processing and modification of tRNA. GDI1: RabGDI alpha makes a complex with geranylgeranylated small GTP-binding proteins of the Rab family and keeps them in the cytosol.
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.
=== Factors found not to correlate with fibromyalgia === Studies on personality and fibromyalgia have shown inconsistent results. Although some have suggested that fibromyalgia patients are more likely to have specific personality traits, it appears that, in comparison to other diseases, when anxiety and depression are statistically controlled for, personality has less relevance, and does not differ from healthy controls.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.