If you have been reading about pentapeptide 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.
Updated 2026-04-19. Numbers and descriptions here follow the published literature rather than marketing material.
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。
At the receptor level, ipamorelin binds GHS-R1a and triggers signaling through Gq-coupled pathways. Activation leads to calcium release and downstream effects in pituitary somatotroph cells. These events promote the release of growth hormone into circulation. The response depends on the presence of the receptor and on the physiological state of the animal or tissue studied. Because the receptor is also found in other tissues, effects beyond the pituitary have been examined in laboratory models, though the extent of those effects remains an area of ongoing study.
One distinguishing feature reported in animal studies is selectivity. Ipamorelin stimulated growth hormone release with limited elevation of adrenocorticotropic hormone or cortisol compared with earlier secretagogues such as GHRP-6. This pattern has been described as more selective for the growth hormone axis. The finding comes mainly from preclinical work, and the degree to which it holds across species and doses is not fully settled. Reports also describe effects on gastric motility in animal models, suggesting activity outside the pituitary, though the clinical relevance of this observation is uncertain.
| 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 |
Selectivity is the property most often attached to this peptide. Published animal and early human studies record increases in growth hormone release after administration, with adrenocorticotropic hormone and cortisol responses remaining small by comparison. Effects on appetite-related pathways also appear weaker than those reported for several earlier secretagogues. Reviews that compare members of the growth hormone secretagogue family cite these findings frequently, though the receptor-level explanation for the selectivity continues to be debated rather than settled.
Ipamorelin is a synthetic pentapeptide classified as a growth hormone secretagogue. Its sequence, Aib-His-D-2-Nal-D-Phe-Lys-NH2, combines three non-proteinogenic residues with a C-terminal amide. The N-terminal aminoisobutyric acid unit and the two aromatic D-amino acids distinguish it from peptides assembled only from standard L-amino acids. Its formula is C38H49N9O5, corresponding to an average mass near 711.9 Da. At neutral pH the molecule carries a net positive charge, a property that shapes its behaviour in chromatographic and electrophoretic systems.
The compound was developed at Novo Nordisk during the 1990s as part of a programme seeking secretagogues with improved selectivity. It was described in the peer-reviewed literature in 1998 alongside related pentapeptides from the same series. Investigators advanced it because it raised growth hormone output in animal models while leaving other pituitary hormones comparatively unaffected. The development code NNC 26-0161 appears in earlier reports, and ipamorelin later became the common designation in published work.
现有文献多来自小规模、短期的研究，涉及生长激素缺乏、术后肠麻痹等方向。长期使用是否导致受体脱敏，以及重复给药后效应是否衰减，仍属开放问题。不同研究之间的剂量、给药途径和受试者特征差异较大，因此结论外推需谨慎。关于临床获益的确切证据尚不充分，需要更大规模的对照试验来澄清。
Ipamorelin 是一种合成五肽，在 20 世纪 90 年代被报道为生长激素促分泌剂。其结构基于胃饥饿素受体激动剂的设计思路，但并非天然激素。早期药理学研究显示，它可刺激垂体释放生长激素，而对应激激素轴的影响相对较小。该化合物常被用作研究生长激素调节通路的工具分子。
=== Cofactors === The reducing agents NADH, NADPH, and FADH2, as well as metal ions, act as cofactors at various steps in anabolic pathways. NADH, NADPH, and FADH2 act as electron carriers, while charged metal ions within enzymes stabilize charged functional groups on substrates.
The rise of cyber as a warfighting domain has led to efforts to determine how cyberspace can be used to foster peace. For example, the German civil rights panel FIfF runs a campaign for cyberpeace − for the control of cyberweapons and surveillance technology and against the militarization of cyberspace and the development and stockpiling of offensive exploits and malware. Measures for cyberpeace include policymakers developing new rules and norms for warfare, individuals and organizations building new tools and secure infrastructures, promoting open source, the establishment of cyber security centers, auditing of critical infrastructure cybersecurity, obligations to disclose vulnerabilities, disarmament, defensive security strategies, decentralization, education and widely applying relevant tools and infrastructures, encryption and other cyberdefenses. The topics of cyber peacekeeping and cyber peacemaking have also been studied by researchers, as a way to restore and strengthen peace in the aftermath of both cyber and traditional warfare.
A DNA construct is an artificially-designed segment of DNA borne on a vector that can be used to incorporate genetic material into a target tissue or cell. A DNA construct contains a DNA insert, called a transgene, delivered via a transformation vector which allows the insert sequence to be replicated and/or expressed in the target cell. This gene can be cloned from a naturally occurring gene, or synthetically constructed. The vector can be delivered using physical, chemical or viral methods. Typically, the vectors used in DNA constructs contain an origin of replication, a multiple cloning site, and a selectable marker. Certain vectors can carry additional regulatory elements based on the expression system involved. DNA constructs can be as small as a few thousand base pairs (kbp) of DNA carrying a single gene, using vectors such as plasmids or bacteriophages, or as large as hundreds of kbp for large-scale genomic studies using an artificial chromosome. A DNA construct may express wildtype protein, prevent the expression of certain genes by expressing competitors or inhibitors, or express mutant proteins, such as deletion mutations or missense mutations. DNA constructs are widely adapted in molecular biology research for techniques such as DNA sequencing, protein expression, and RNA studies.
=== Physiological effects === According to a dose-response study in human subjects, dimethyltryptamine administered intravenously slightly elevated blood pressure, heart rate, pupil diameter, and rectal temperature, in addition to elevating blood concentrations of beta-endorphin, corticotropin, cortisol, and prolactin; growth hormone blood levels rose equally in response to all doses of DMT, and melatonin levels were unaffected."
Sources: en.wikipedia.org
. A 2022 paper provides a less costly, dynamical and recurrent solution of the Navier-Stokes equation for 3D turbulent fluid flows. On suitably short time scales, the dynamics of turbulence is deterministic.
military operation as "legitimate" and "defensive intervention." She reaffirmed the government's support for a democratic transition in Venezuela, condemned repression by the Maduro government, whose electoral victory it does not recognize, and stated that while Italy opposes external military intervention, it considers defensive action against hybrid threats to national security, including those linked to state actors involved in narcotrafficking, to be legitimate. Kosovo: President Vjosa Osmani expressed her support for the US, stating that "Kosovo understands the impact of American resolve – our liberation is a testament to that. At a time when the US is confronting tyranny in Venezuela, we must all reinforce this stance, because the transatlantic community is strongest when united behind American leadership and shared values. When America leads, we stand proudly together – because our collective freedom depends on it." Prime Minister Albin Kurti also expressed his full support for the US, arguing that the strikes were in defense of Western democratic values. Liechtenstein: The government of Liechtenstein called for adherence to international law. Malta: The Maltese government, which had not recognised Maduro's legitimacy, called for de-escalation and respect for international law. North Macedonia: Foreign Minister Timčo Mucunski welcomed President Donald Trump's announcement that Nicolás Maduro had been arrested and would face justice.
== Prognosis == Overall, the clinical prognosis for calciphylaxis is poor. The 1-year mortality rate in patients who have end-stage kidney disease is 45-80%. Median survival in patients who do not have end-stage kidney disease is 4.2 months. Response to treatment is not guaranteed. The most common cause of death in calciphylaxis patients is sepsis, severe infection originating from a non-healing ulcer.
== Research == IMPDH inhibitors have been shown to prevent SARS-CoV-2 replication in cells and are being tested in clinical trials for COVID-19. Recently, several IMPDH inhibitors, including AVN-944, have been identified as promising compounds against Trypanosoma cruzi, the etiological agent of Chagas disease.
On 2 March 1864, the Russian authority, compelled by the uprising to compete for the loyalty of Polish peasants, officially published an enfranchisement decree in Congress Poland along the lines of an earlier land reform proclamation of the insurgents. The act created the conditions necessary for the development of the capitalist system on central Polish lands. At the time when most Poles realized the futility of armed resistance without external support, the various sections of Polish society were undergoing deep and far-reaching evolution in the areas of social, economic and cultural development.
Sources: en.wikipedia.org
Hancock, David (2001). The Mastiffs: The Big Game Hunters – Their History, Development and Future. Ducklington, Oxon: Charwynne Dog Features. ISBN 9780951780114. Fogle, Bruce (2009). The Encyclopedia of the Dog. New York: DK Publishing. ISBN 978-0-7566-6004-8. Encyclopædia Britannica (2019). "Mastiff: breed of dog". www.britannica.com. Encyclopædia Britannica, Inc. Retrieved 9 September 2019. Parker, Heidi G. (2012). "Chapter 3: The history and relationship of dog breeds". In Ostrander, Elaine A.; Ruvinsky, Anatoly (eds.). The Genetics of the Dog. Wallingford, Oxfordshire: CAPI books. pp. 38–53. ISBN 9781845939403. Oxford Dictionaries (2019). "Mastiff". Lexico.com. Oxford University Press. Retrieved 9 September 2019. Wynn, M. B. (1886). History of the Mastiff: Gathered from Sculpture, Pottery, Carvings, Paintings and Engravings. Melton Mowbray, William Loxley. ISBN 978-1-4465-4892-9. {{cite book}}: ISBN / Date incompatibility (help) Young, Amy; Bannasch, Danika (2007). "Chapter 4: Morphological variation in the dog". In Ostrander, Elaine A.; Giger, Urs; Lindblad-Toh, Kerstin (eds.). The Dog and its Genome. Cold Spring Harbor, New York: Cold Spring Harbor Laboratory Press. pp. 47–66. ISBN 9780879697815.
=== Authorizations of COVID-19 vaccines === The COVID-19 pandemic, and sequencing of the causative virus SARS-CoV-2 at the beginning of 2020, led to the rapid development of the first approved mRNA vaccines. BioNTech and Moderna in December of the same year obtained approval for their mRNA-based COVID-19 vaccines. In December 2020, the UK Medicines and Healthcare products Regulatory Agency (MHRA) became the first global medicines regulator in history to approve an mRNA vaccine, granting emergency authorization for Pfizer–BioNTech's BNT162b2 COVID-19 vaccine for widespread use. Also, in December 2020, the US Food and Drug Administration gave emergency use authorization for the Pfizer–BioNTech COVID-19 vaccine and the Moderna COVID-19 vaccine.
Last but not least, specific cleavage of poly (ADP-ribose) polymerase (PARP) and a decrease in pro-caspase9 and 3 were also induced by arenobufagin treatment. PARP is mainly involved in cell repair and programmed cell death. After treatment with arenobufagin, some cells make more autophagosomes and lysosomes, whereas other cells undergo apoptosis. Arenobufagin also leads to increased expression of LC3-II, Biclin1(initial vesicle formation), Atg5 (elongation and completion), Atg9, Atg16L1 and p62/SQSTM1, all proteins which induce autophagy. Blockers of autophagy increase the cytotoxic effect of arenobufagin. Addition of 3-MA increases the proportion of cells in which there in enlarged PARP cleavage and limited caspase-9 and caspase-3 cleavage. This indicates that autophagy pathways protect the cell against apoptosis by arenobufagin. It was hypothesized that arenobufagin may inhibit the PI3K/Akt pathway in controlling cell death and differentiation in response to external stimuli. It was found that arenobufagin inhibited the proteins Akt, PDK1 and PI3K, whereas it stimulated the PHEN-protein. It does this by altering the degree of phosphorylation. All these proteins are involved in the PI3/Akt pathway. Further down the pathway, arenobufagin indirectly inhibits the mTOR-protein, which is involved in apoptosis as well as in autophagy. The biotransformation of arenobufagin by Alternaria alternata leads to the following three metabolites: 3-oxo-arenobufagin (1a), ψ-bufarenogin (1b), and 3- oxo- ψ-bufarenogin (1c).
== Athletic performance enhancement == There is evidence that β-alanine supplementation can increase exercise and cognitive performance, for some sporting modalities, and exercises within a 0.5–10 min time frame. β-alanine is converted within muscle cells into carnosine, which acts as a buffer for the lactic acid produced during high-intensity exercises, and helps delay the onset of neuromuscular fatigue. Ingestion of β-alanine can cause paraesthesia, reported as a tingling sensation, in a dose-dependent fashion. Aside from this, no important adverse effect of β-alanine has been reported, however, there is also no information on the effects of its long-term usage or its safety in combination with other supplements, and caution on its use has been advised. Furthermore, many studies have failed to test for the purity of the supplements used and check for the presence of banned substances.
== Background/History == Izon Science Limited is a company incorporated as Australo Ltd. on January 10, 2005, by four New Zealand-based scientists. In 2007, Hans van der Voorn became CEO, and on November 17, 2008, the company was renamed Izon Science Limited. Initially focused on developing tunable resistive pulse sensing instruments for nanoparticle characterization, the company later expanded into developing tools for isolating exosomes and other extracellular vesicles from biological fluids. Presently, Izon Science develops and manufactures tools for nanoparticle characterization and separation, catering to academic researchers and diagnostics companies working with extracellular vesicles, as well as those involved in nanomedicine, viruses, and virus-like particles. The Exoid is one of Izon's latest tunable resistive pulse sensing instruments, succeeding the qViro-X, qMicro, and qNano. In June 2021, Izon Science relocated its headquarters from Burnside (Christchurch) to a larger facility on Show Place, Addington (Christchurch). The company currently employs approximately 70 individuals. Izon has received investment funds from Bolton Equities, a privately funded investor group based in New Zealand. Research partnerships include the University Medical Center Utrecht and the VU University Medical Center in the Netherlands, the Mayo Clinic, the National Institutes of Health, and Massachusetts General Hospital.
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。