If you have been reading about ESI-MS 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 2025-09-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
从用途定位看，ipamorelin 目前主要以研究用肽的身份被讨论，未见主要药品监管机构将其批准为治疗药物。市售材料通常标注仅供研究使用，不得用于人体或诊断程序。文献中它常与生长激素促分泌素、GHS-R1a 激动剂、胃饥饿素拟似物等表述并列出现。既有研究的样本量普遍偏小，因此对其效应强度与一致性的描述应保持谨慎。
Ipamorelin 是一种合成五肽，序列为 Aib-His-D-2-Nal-D-Phe-Lys-NH2，分子式 C38H49N9O5，游离碱分子量约 711.85 g/mol。它属于生长激素促分泌素（GHS）家族，作用靶点是胃饥饿素受体 GHS-R1a。该化合物由诺和诺德的研究团队在二十世纪九十年代末报道，设计目标是提高对生长激素释放的选择性。C 端酰胺化与 N 端 Aib 残基是两个用于抵抗肽酶降解的结构特征。
在 GHS 家族中，早期肽类如 GHRP-6 与 GHRP-2 会同时促进生长激素、皮质醇与催乳素的释放，并明显增加食欲。Ipamorelin 在动物与早期人体研究中表现出对生长激素释放的相对选择性，对上述其他激素的影响较小。这种差异通常归因于受体结合模式与下游信号偏向的不同，而完整的分子解释仍有待补充。需要区分的是，选择性是研究观察中的相对程度，并非绝对界限。
Lyophilized material is generally stored cold and dry, with desiccant, and protected from light. In solution the peptide is more vulnerable: the histidine side chain can oxidize, and repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. A mildly acidic aqueous buffer is often used for short-term handling because it limits several degradation routes. Accurate prediction of long-term stability under a given set of conditions is difficult, and published stability data remain sparse.
Published discussion of this compound is uneven. Some references describe it as a tool for probing growth hormone regulation, while others focus on analytical characterization or on comparisons with related secretagogues. Statements about selectivity, half-life and potency often trace back to a small number of original reports that later authors cite secondhand. Readers evaluating a claim should therefore check whether a figure reflects a direct measurement or a repeated citation, and whether the underlying study was conducted in animals, in isolated cells or in human volunteers.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C38H49N9O5 | 五肽，C 端酰胺化 |
| 分子量 | 约 711.85 g/mol | 游离碱形式 |
| 外观 | 白色至类白色冻干粉 | 研究用材料的常见形态 |
| 溶解性 | 溶于水及 DMSO 等极性溶剂 | 建议现配现用 |
| 储存温度 | -20 °C 或更低 | 干燥、避光、限制冻融次数 |
Material supplied for research use is normally a white to off-white lyophilized powder. The solid is hygroscopic and is handled in a low-humidity environment to limit water uptake. Bulk quantities are frequently shipped in sealed vials under inert gas. Once reconstituted in water or a neutral buffer, the solution is less stable than the dry powder and is usually divided into single-use aliquots.
Long-term storage of the dry powder is typically at minus twenty degrees Celsius or lower, protected from light and moisture. Solutions are commonly kept frozen and thawed only once, because repeated freeze-thaw cycles can promote aggregation and loss of measurable peptide content. Buffers near neutral pH are preferred over strongly acidic or strongly basic conditions. Shipping at ambient temperature is acceptable for short periods when the powder remains sealed and desiccated.
Nihonium has no stable or naturally occurring isotopes. Several radioactive isotopes have been synthesised in the laboratory, either by fusing two atoms or by observing the decay of heavier elements. Eight different isotopes of nihonium have been reported with atomic masses 278, 282–287, and 290 (287Nh and 290Nh are unconfirmed); they all decay through alpha decay to isotopes of roentgenium. There have been indications that nihonium-284 can also decay by electron capture to copernicium-284, though estimates of the partial half-life for this branch vary strongly by model. A spontaneous fission branch of nihonium-285 has also been reported.
The subsequent Soviet submarine attacks and air raids cause serious damage to Merchant Marine ships and naval vessels in Atlantic convoys, hindering NATO's war effort during the defense against the less-successful Soviet invasion of West Germany. Early editions of the Harpoon naval warfare simulation were based around defending the GIUK Gap. Tom Clancy used the simulation to test the naval battles for Red Storm Rising. The location of Iceland in the gap made it a participant in the Cold War and a target for a nuclear strike, especially through the introduction of the aforementioned Keflavik atomic bomber NATO base. Halldór Laxness dramatized the tension of these geopolitics from the perspective of an Icelandic maid in the novel The Atom Station.
=== Names === Chlorphenamine is the INNTooltip International Nonproprietary Name while chlorpheniramine is the USANTooltip United States Adopted Name and former BANTooltip British Approved Name. Brand names include Chlor-Trimeton, Demazin, Allerest 12 Hour, Piriton, Chlorphen-12, Tylenol Cold/Allergy, and numerous others according to country.
=== Drug addiction === It has been found that cocaine produces a decrease in Cystine-Glutamate exchange via system Xc-, leading to a decrease in basal, extra synaptic glutamate levels in the nucleus accumbens core (NAcc) region of the brains of cocaine-withdrawn rats. It has also been observed in withdrawn rats that a decrease in Group 2 mGluR inhibition of vesicular release, most likely due to the decrease in extrasynaptic glutamate levels, leads to an increase in cocaine-evoked glutamate signaling in their NAcc. An infusion of cysteine in the NAcc of withdrawn rats leads to an increase in extrasynaptic glutamate, near the levels of the control rats, and prevents an increase in synaptic glutamate signaling after a cocaine injection. These findings suggest there is a decrease in system Xc- activity in cocaine-withdrawn rats. It has also been found that cocaine increases glutamate signaling in the synaptic cleft, further supporting this conclusion. Administration of the cysteine prodrugs N-acetylcysteine or L-2-oxothiazolidine-4-carboxylate blocks cocaine reinstatement in rats. N-acetylcysteine has been shown to decrease drug-seeking behavior for nicotine and heroin as well. However, N-acetylcysteine does not alter the cocaine-induced rush or euphoria; it only causes a reduction in drug-seeking behavior. N-acetylcysteine works by increasing levels of cysteine in cells, leading to an increase in system Xc- activity.
Sources: en.wikipedia.org
==== Protein DAMPs ==== High-mobility group box 1: HMGB1, a member of the HMG protein family, is a prototypical chromatin-associated LSP (leaderless secreted protein), secreted by hematopoietic cells through a lysosome-mediated pathway. HMGB1 is a major mediator of endotoxin shock and is recognized as a DAMP by certain immune cells, triggering an inflammatory response. It is known to induce inflammation by activating NF-κB pathway by binding to TLR, TLR4, TLR9, and RAGE (receptor for advanced glycation end products). HMGB1 can also induce dendritic cell maturation via upregulation of CD80, CD83, CD86 and CD11c, and the production of other pro-inflammatory cytokines in myeloid cells (IL-1, TNF-a, IL-6, IL-8), and it can lead to increased expression of cell adhesion molecules (ICAM-1, VCAM-1) on endothelial cells. DNA and RNA: The presence of DNA anywhere other than the nucleus or mitochondria is perceived as a DAMP and triggers responses mediated by TLR9 and DAI that drive cellular activation and immunoreactivity. Some tissues, such as the gut, are inhibited by DNA in their immune response because the gut is filled with trillions of microbiota, which help break down food and regulate the immune system. Without being inhibited by DNA, the gut would detect these microbiota as invading pathogens, and initiate an inflammatory response, which would be detrimental for the organism's health because while the microbiota may be foreign molecules inside the host, they are crucial in promoting host health.
== Notes == "EMDB-1067: Ribosomal 80S-eEF2-sordarin complex from S. cerevisiae - EM Navigator". emnavi.protein.osaka-u.ac.jp. Retrieved 2009-08-06.{{cite web}}: CS1 maint: deprecated archival service (link) Giavalisco P, Wilson D, Kreitler T, et al. (March 2005). "High heterogeneity within the ribosomal proteins of the Arabidopsis thaliana 80S ribosome". Plant Mol. Biol. 57 (4): 577–591. Bibcode:2005PMolB..57..577G. doi:10.1007/s11103-005-0699-3. hdl:11858/00-001M-0000-0010-86C6-1. PMID 15821981. S2CID 14500573. "Ribosomes". www.cs.stedwards.edu. Archived from the original on 2009-03-20. Retrieved 2009-08-06.
=== Campaign methods === Given the high national profile that Sanders maintained since his 2016 campaign, NPR described him as "no longer an underdog" when he announced his 2020 campaign. Using the large email list it built during the 2016 campaign, the 2020 campaign recruited more than one million volunteers within weeks of its launch. It enlisted several former NowThis News employees to produce professional videos for wide social media distribution, live-streamed various forums to its millions of social media followers, and launched a podcast and smartphone app for grassroots organizing.
Sources: en.wikipedia.org
两者都是 GHS-R1a 激动剂，但 ipamorelin 在研究中显示出更高的生长激素释放选择性。早期资料显示它对皮质醇、催乳素与食欲的刺激弱于 GHRP-6。这些差异是相对程度，而非绝对区分。
公开资料中它主要以研究用肽的形式出现，未获主要监管机构批准用于治疗。可得材料通常标注仅供研究使用。任何临床用途的宣称都缺少监管依据。
序列中的 Aib 与 D-2-Nal 等非天然残基可提高对肽酶的抵抗能力，并影响受体结合的构象。这类修饰在合成肽设计中较为常见。它们也使常规氨基酸分析需要额外步骤才能确认序列。
Aib 即 α-氨基异丁酸，是一种非蛋白质源氨基酸，其侧链为两个甲基。它在肽链中倾向于诱导螺旋构象并限制骨架的柔性。这种刚性被认为有助于抵抗蛋白酶切割。