Semax 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.
Updated 2025-11-30. Numbers and descriptions here follow the published literature rather than marketing material.
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
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.
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.
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.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
This was achieved in 2010 when mature cardiac fibroblasts were reprogrammed directly into cardiomyocyte-like cells. This was done using three transcription factors: GATA4, Mef2c, and Tbx5. Cardiac fibroblasts make up more than half of all heart cells and are usually not able to conduct contractions (are not cardiogenic), but those reprogrammed were able to contract spontaneously. The significance is that fibroblasts from the damaged heart or from elsewhere, may be a source of functional cardiomyocytes for regeneration. Simply injecting functioning cardiac cells into a damaged heart is only partially effective. In order to achieve more reliable results, structures composed of the cells need to be produced and then transplanted. Masumoto and his team designed a method of producing sheets of cardiomyocytes and vascular cells from human iPSCs. These sheets were then transplanted onto infarcted hearts of rats, leading to significantly improved cardiac function. These sheets were still found to be present four weeks later. Research has also been conducted into the engineering of heart valves. Tissue-engineered heart valves derived from human cells have been created in vitro and transplanted into a non-human primate model. These showed a promising amount of cellular repopulation even after eight weeks, and succeeded in outperforming currently-used non-biological valves. In 2021, researchers demonstrated a switchable iPSCs-reprogramming-based approach for regeneration of damaged heart without tumor-formation in mice.
== Function == Nicotinamide phosphoribosyltransferase (iNAMPT) catalyzes the condensation of phosphoribosyl pyrophosphate with nicotinamide (NAM) to yield nicotinamide mononucleotide (NMN) and pyrophosphate (PPi). This is the first step in the biosynthesis of nicotinamide adenine dinucleotide (NAD+). This reaction allows a salvage pathway, in which NAM is recycled from enzymes that use NAD+ (sirtuins, PARPs, CD38) as these produce NAM as a waste product. Thus this reaction is a major source of NAD+ production in the body. De novo synthesis of NAD+ from tryptophan occurs only in the liver and kidney, overwhelmingly in the liver.
== Career == Upon receiving his Ph.D., Gattuso moved to Australia where he was a postdoctoral researcher at the Australian Institute of Marine Science(1988-1990). In 1990, Gattuso took a position of CNRS research scientist at Centre de Biologie et Écologie Tropicale et Méditerranéenne of the University of Perpignan (1990-1992). He then moved to the Scientific Center of Monaco to launch and lead the Ecophysiology and Biogeochemistry group. In 1998, Gattuso went back to a CNRS joint laboratory at the Villefranche Oceanographic Observatory and moved to the ranks of Research Professor (directeur de recherche). He is also Associate Scientist at the Institute for Sustainable Development and International Relations (IDDRI-SciencesPo, Paris). Gattuso has been visiting professor or scientist at Rutgers University, the National Center for Atmospheric Research and Shantou University. Gattuso is the founding editor-in-chief of Biogeosciences and served or has served in the editorial board of several scientific journals. He founded the Biogeosciences Division of the European Geosciences Union, and has received multiple awards and honors for his research contributions. He led the launch of the Ocean Acidification International Coordination Centre at the International Atomic Energy Agency, co-edited the first book on ocean acidification (Oxford University Press) and contributed to several IPCC products (5th Assessment Report, Special Report on 1.5°C of Warming, and the Special Report on the Ocean and Cryosphere in a Changing Climate).
Sources: en.wikipedia.org
However, as the atrial baroreceptors increase their rate of firing and as they stretch due to the increased blood pressure, the cardiac center responds by increasing sympathetic stimulation and inhibiting parasympathetic stimulation to increase heart rate. The opposite is also true. Chemoreceptors present in the carotid body or adjacent to the aorta in an aortic body respond to the blood's oxygen, carbon dioxide levels. Low oxygen or high carbon dioxide will stimulate firing of the receptors. Exercise and fitness levels, age, body temperature, basal metabolic rate, and even a person's emotional state can all affect the heart rate. High levels of the hormones epinephrine, norepinephrine, and thyroid hormones can increase the heart rate. The levels of electrolytes including calcium, potassium, and sodium can also influence the speed and regularity of the heart rate; low blood oxygen, low blood pressure and dehydration may increase it.
Methods incorporating chromatography generally begin with cryo-depleted plasma undergoing buffer exchange via either diafiltration or buffer exchange chromatography, to prepare the plasma for following ion exchange chromatography steps. After ion exchange, generally purification steps and buffer exchange occur. However, chromatographic methods began to be adopted in the 1980s. Developments were ongoing between when Cohn fractionation started emerge in 1946, and when chromatography emerged, in 1983. In 1962, the Kistler and Nistchmann process was created as a spin-off of the Cohn process. In the 1990s, the Zenalb and the CSL Albumex processes were created, which incorporated chromatography with variations. The general approach to using chromatography for plasma fractionation for albumin is: recovery of supernatant I, delipidation, anion exchange chromatography, cation exchange chromatography, and gel filtration chromatography. The recovered purified material is formulated with combinations of sodium octanoate and sodium N-acetyl tryptophanate and then subjected to viral inactivation procedures, including pasteurization at 60 °C. This is a more efficient alternative than the Cohn process because:
=== Effects on health === The US Food and Drug Administration has determined there is little credible evidence that tomatoes or tomato-based foods reduce the risk of various types of cancer. In a 2011 scientific review, the European Food Safety Authority concluded that lycopene did not favorably influence DNA, skin exposed to ultraviolet radiation, heart function or vision.
Sources: en.wikipedia.org
Before the 1980s, cannabinoids were thought to produce their effects via nonspecific interaction with cell membranes, rather than specific membrane-bound receptors. The discovery of cannabinoid receptors in the 1980s resolved this debate. These receptors are common in animals, with two primary types, CB1 and CB2, and evidence suggests additional receptors may exist. The human brain has more cannabinoid receptors than any other G protein-coupled receptor (GPCR) type. The endocannabinoid system (ECS) regulates multiple functions, including movement, motor coordination, learning, memory, emotion, motivation, addictive-like behavior, and pain modulation.
Ruminant animals can obtain protein from at least some forms of non-protein nitrogen (NPN) through fermentation by their rumen bacteria, hence NPN is often added to their diet to supplement protein. Nonruminants such as cats, dogs and pigs (and humans) cannot utilize NPN. NPN are given to ruminants in the form of pelleted urea, ammonium phosphate and/or biuret. Sometimes slightly polymerized special urea-formaldehyde resin or a mixture of urea and formaldehyde (both are also known as formaldehyde-treated urea) is used in place of urea, because the former provides a better control on the nitrogen release. This practice is carried out in China and other countries, such as Finland, India and France. Cyanuric acid has also been used as NPN. For example, Archer Daniels Midland manufactures an NPN supplement for cattle, which contains biuret, triuret, cyanuric acid and urea. FDA permits a certain amount of cyanuric acid to be present in some additives used in animal feed and also drinking water. Melamine use as NPN for cattle was described in a 1958 patent. In 1978, however, a study concluded that melamine "may not be an acceptable nonprotein N source for ruminants", because its hydrolysis in cattle is slower and less complete than other nitrogen sources such as cottonseed meal and urea. In China, it is known that ground urea-formaldehyde resin is a common adulterant in feed for non-ruminants. Domestically it is often sold under the euphemism "protein essence" (蛋白精) and is described as "one kind of new proteinnitrogen feed additive".
==== Different Conservative Party leaders: voting intention and seat projections ==== For the 2024 Conservative Party leadership election, Electoral Calculus conducted a multilevel regression with poststratification (MRP) opinion poll on behalf of Jack Lewy of the Robert Jenrick campaign, asking the general public how they would vote if respectively Kemi Badenoch or Robert Jenrick were elected leader of the Conservatives.
Sources: en.wikipedia.org
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.