Semax raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-11-18. Anything still debated is marked as such rather than presented as settled.
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。
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
| 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 whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
=== Classification === The common type is sIBM; it strikes individuals apparently at random. There is a type that has been observed in multiple siblings in the same generation in several families, termed familial inflammatory sIBM, but it is not passed on from generation to generation. There are also several very rare forms of hereditary inclusion body myopathy (hIBM) that are linked to specific genetic defects and that are passed on from generation to generation, each inherited in different ways.
== Function == This type of connective tissue is found mostly in the reticular layer (or deep layer) of the dermis. It is also in the sclera and in the deeper skin layers. Due to a high content of type I collagen, dense irregular connective tissue provides strength, making the skin resistant to tearing by stretching forces from different directions. Dense irregular connective tissue also makes up submucosa of the digestive tract, lymph nodes, and some types of fascia. Other examples include periosteum and perichondrium of bones, and the tunica albuginea of testis. In the submucosa layer, the fiber bundles course in varying planes allowing the organ to resist excessive stretching and distension.
== Functions == Mitochondrial creatine kinase (CKm) is present in the mitochondrial intermembrane space, where it regenerates phosphocreatine (PCr) from mitochondrially generated ATP and creatine (Cr) imported from the cytosol. Apart from the two mitochondrial CK isoenzyme forms, that is, ubiquitous mtCK (present in non-muscle tissues) and sarcomeric mtCK (present in sarcomeric muscle), there are three cytosolic CK isoforms present in the cytosol, depending on the tissue. Whereas MM-CK is expressed in sarcomeric muscle, that is, skeletal and cardiac muscle, MB-CK is expressed in cardiac muscle, and BB-CK is expressed in smooth muscle and in most non-muscle tissues. Mitochondrial mtCK and cytosolic CK are connected in a so-called PCr/Cr-shuttle or circuit. PCr generated by mtCK in mitochondria is shuttled to cytosolic CK that is coupled to ATP-dependent processes, e.g. ATPases, such as acto-myosin ATPase and calcium ATPase involved in muscle contraction, and sodium/potassium ATPase involved in sodium retention in the kidney. The bound cytosolic CK accepts the PCr shuttled through the cell and uses ADP to regenerate ATP, which can then be used as an energy source by the ATPases (CK is associated intimately with the ATPases, forming a functionally coupled microcompartment). PCr is not only an energy buffer, but also a cellular transport form of energy between subcellular sites of energy (ATP) production (mitochondria and glycolysis) and those of energy utilization (ATPases).
Sources: en.wikipedia.org
== Adverse effects == Immunotherapies as a group have off-target effects and toxicities common to them. Some of these include interstitial pneumonitis, colitis, hepatitis, thyroiditis, skin reactions, low levels of platelets and white blood cells, inflammation of the brain or spinal cord, neuromuscular adverse events including myositis, Guillain–Barré syndrome, myasthenia gravis; myocarditis and cardiac insufficiency, acute adrenal insufficiency, and nephritis. The most common kidney related changes are acute interstitial nephritis, followed by glomerular diseases and then tubular damage. The detailed mechanism of these adverse effects are not fully elucidated; however, they are clearly different from known autoimmune diseases. Immune-mediated adverse reactions are usually attributed to generalised dysregulation of T cells or development of autoantibodies, although memory T cell responses against occult viral infections might also play a role in some patients with advanced melanoma following combined PD-1/CTLA-4 blockade. When compared with standard chemotherapeutic agents, PD-1/PD-L1 inhibitors had a lower reported incidence of fatigue, sensory neuropathy, diarrhea, bone marrow suppression, loss of appetite, nausea, and constipation.
=== Lawsuit against WTVT === In 1997, the news division of WTVT (Channel 13), a Fox-owned station in Tampa, Florida, planned to air an investigative report by Steve Wilson and Jane Akre on the health risks associated with Monsanto's bovine growth hormone product, Posilac. Just before the story was to air, Fox received a letter from Monsanto saying the reporters were biased and that the story would damage the company. Akre stated that Wilson and she went through 83 rewrites over eight months. Negotiations broke down and both reporters were eventually fired. Wilson and Akre alleged the firing was for retaliation, while WTVT contended they were fired for insubordination. The reporters then sued Fox/WTVT in Florida state court under the state's whistleblower statute. In 2000, a Florida jury found that while no evidence showed Fox/WTVT had bowed to any pressure from Monsanto to alter the story, Akre, but not Wilson, was a whistleblower and was unjustly fired. She was awarded a $425,000 settlement. At the time of the decision, "the station claimed it did not bend to Monsanto's letter and wanted to air a hard-hitting story with a number of statements critical of Monsanto." Fox appealed the decision stating that under Florida law, a whistleblower can only act if "a law, rule, or regulation" has been broken and argued that the FCC's policy against distortions or misrepresentations presented as news did not fit that definition.
Adrien-Marie Legendre (; French: [adʁiɛ̃ maʁi ləʒɑ̃dʁ]; 18 September 1752 – 9 January 1833) was a French mathematician who made numerous contributions to mathematics. Well-known and important concepts such as the Legendre polynomials and Legendre transformation are named after him. He is also known for his contributions to the method of least squares, and was the first to officially publish on it, though Carl Friedrich Gauss had discovered it before him.
Sources: en.wikipedia.org
== Function == The cell bodies produce the peptide hormone vasopressin, which is also known as anti-diuretic hormone (ADH), and the peptide hormone oxytocin. Both of these peptides are released from the posterior pituitary. ADH travels via the bloodstream to its target cells in the papillary ducts in the kidneys, enhancing water reabsorption. Oxytocin travels via the bloodstream to act at the mammary glands and the uterus. In the cell bodies, the hormones are packaged in large, membrane-bound vesicles that are transported down the axons to the nerve endings. The secretory granules are also stored in packets along the axon called Herring bodies. Similar magnocellular neurons are also found in the paraventricular nucleus.
=== Amanda: Two Girls, One Cage === First aired: 18 November 2010 Meet Amanda, Bully Beatdown's first female bully with a bad attitude. She stands at 5'7 and makes life miserable for her victim, Keiko. Keiko is the second female victim to appear on the show, the first being Linda. Amanda calls herself "the queen" so Mayhem Miller brings in female MMA fighter Michelle Waterson who's done kickboxing since she was 10 years old to teach her a lesson. In the first round, she tapped out five times. In the second round, Amanda got KO'd with a brutal punch to her stomach. Keiko won $10,000 and an apology from Amanda.
== History == The first known reference to the dura appears in Egypt, in Case 6 of the Edwin Smith Papyrus. Hippocrates described the dura in his monograph "On Injuries of the Head" and insisted that care should be taken to keep it intact and clean. Celsus agreed, and described a method of treatment for depressed fractures. Galen was the first to describe the pia mater in humans in the second century AD.
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。
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.