Melanocortin receptor 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 2026-07-02 and is reviewed periodically as new material appears.
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 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。
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.
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.
| 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 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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
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.
In Konsumentombudsmannen v Gourmet AB the Court suggested that a total ban for advertising alcohol on the radio, TV and in magazines could fall within article 34 where advertising was the only way for sellers to overcome consumers' "traditional social practices and to local habits and customs" to buy their products, but again the national courts would decide whether it was justified under article 36 to protect public health. Under the Unfair Commercial Practices Directive, the EU harmonised restrictions on restrictions on marketing and advertising, to forbid conduct that distorts average consumer behaviour, is misleading or aggressive, and sets out a list of examples that count as unfair. Increasingly, states have to give mutual recognition to each other's standards of regulation, while the EU has attempted to harmonise minimum ideals of best practice. The attempt to raise standards is hoped to avoid a regulatory "race to the bottom", while allowing consumers access to goods from around the continent.
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The GlyR agonism of sarcosine is relevant at concentrations frequently used in experimental settings (0.5–2 mM), complicating the pharmacological interpretation. Aside from effects on glycine-related structures and NMDA receptors, sarcosine has been shown to modulate AMPA receptor function and downstream mTOR signalling in rodent models of depression. Long-term sarcosine administration (21 days) ameliorated chronic unpredictable stress-induced depressive behaviour in rats In the rat forced swim test, a single systemic dose of sarcosine produced rapid antidepressant-like effects accompanied by increased phosphorylation of mTOR and its upstream kinases in the hippocampus, and these behavioural and molecular effects were abolished by pretreatment with the AMPA receptor antagonist NBQX or the mTOR inhibitor rapamycin. Sarcosine also increased phosphorylation of the GluR1 subunit at the protein kinase A site Ser845, a change commonly interpreted as enhanced AMPA receptor membrane insertion. Cryo-EM study published in 2025 resolved the structure of human GlyT1 in complex with sarcosine at 2.8 Å resolution, revealing the transporter in an occluded conformation.
Sources: en.wikipedia.org
=== Release === Generally, a neurotransmitter is released via exocytosis at the presynaptic terminal in response to an electrical signal called an action potential in the presynaptic neuron. However, low-level "baseline" release also occurs without electrical stimulation. Neurotransmitters are released into and diffuse across the synaptic cleft, where they bind to specific receptors on the membrane of the postsynaptic neuron.
The city's main opera house is Teatro Regio di Torino, where Puccini premiered his La bohème in 1896. It was burned down in 1936 and was rebuilt after World War II. On 8 October 2021, the European Broadcasting Union (EBU) and RAI announced that the city would host the Eurovision Song Contest 2022, following Italy's victory at the 2021 contest in Rotterdam, Netherlands, with the song "Zitti e buoni", performed by Måneskin. The contest took place at the Pala Alpitour, with both semi-finals of the contest took place on 10 and 12 May, and the grand final on 14 May. It was the first time that Turin has hosted the contest and the third time that Italy has hosted the contest overall, with the last being in Rome in 1991.
=== Other uses in performing arts === "Access all areas", a form of backstage pass Association of Amateur Artists, a theatre association in Peru Asia Artist Awards, the South Korean annual award ceremony hosted by Star News 98.9 FM (Brisbane), also known as Triple A Murri Country, an Australian community radio station
Sources: en.wikipedia.org
Formaldehyde levels in building environments are affected by a number of factors. These include the potency of formaldehyde-emitting products present, the ratio of the surface area of emitting materials to volume of space, environmental factors, product age, interactions with other materials, and ventilation conditions. Formaldehyde emits from a variety of construction materials, furnishings, and consumer products. The three products that emit the highest concentrations are medium-density fiberboard, hardwood plywood, and particle board. Environmental factors such as temperature and relative humidity can elevate levels because formaldehyde has a high vapor pressure. Formaldehyde levels from building materials are the highest when a building first opens because materials would have less time to off-gas. Formaldehyde levels decrease over time as the sources suppress. In operating rooms, formaldehyde is produced as a byproduct of a process known as electrosurgery and is present in surgical smoke, exposing surgeons and healthcare workers to potentially unsafe concentrations. Formaldehyde levels in air can be sampled and tested in several ways, including impinger, treated sorbent, and passive monitors. The National Institute for Occupational Safety and Health (NIOSH) has measurement methods numbered 2016, 2541, 3500, and 3800.
== Function == EBP functions as a Δ8–Δ7 sterol isomerase, catalyzing the migration of the double bond in the sterol B-ring from the 8(9) to the 7(8) position. In the Bloch pathway of cholesterol biosynthesis, EBP converts zymosterol to dehydrolathosterol, while in the Kandutsch–Russell pathway it converts zymostenol to lathosterol.
He said he supported "bipartisan comprehensive immigration reform", which he had called for during his 2018 gubernatorial campaign. Pritzker also said he supported the deportation of undocumented immigrants who had been convicted of violent crimes, saying, "violent criminals have no place on our streets; if they are undocumented, we want them out of Illinois and out of our country". In 2025, Pritzker spoke out against the Trump administration's Operation Midway Blitz, an operation cracking down on undocumented immigrants in Chicago. He said the operation was targeting law-abiding minority Chicagoans and not cooperating with local authorities.
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 based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.