A practical reference on pentapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-06. Anything still debated is marked as such rather than presented as settled.
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。
杂质谱一般包含缺失序列片段、差向异构体、氧化产物以及残留溶剂或反离子，其中组氨酸与芳香残基的氧化常被重点关注。反相色谱中这类杂质往往紧邻主峰洗脱，因此方法需要足够的分离度并经过系统适用性验证。纯度百分比的解读依赖于检测波长与梯度条件，不同实验室公布的数字不宜直接横向比较。参考标准品有助于跨批次对照，但其自身赋值同样需要可追溯来源。
冻干状态下的肽通常比溶液状态更稳定，常规做法是维持 -20 °C 或更低温度、保持干燥并避开强光。复溶后的降解主要来自水解、氧化与脱酰胺，速率受 pH、缓冲液种类、离子强度与温度共同影响，碱性条件一般会加快这些反应。反复冻融会造成聚集与容器吸附损失，分装保存能降低该风险。容器材质与金属离子也可能参与氧化过程，需与操作条件一并考虑。
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
| Property | Value | Notes |
|---|---|---|
| 分子式 | C38H49N9O5 | 五肽，含非天然氨基酸残基 |
| 分子量 | 711.85 g/mol | 理论值，盐形式可能略有差异 |
| 外观 | 白色至类白色粉末 | 冻干粉常见 |
| 溶解性 | 易溶于水 | 也可溶于部分极性有机溶剂 |
| 储存条件 | -20°C，干燥避光 | 长期保存通常推荐 |
Compared with earlier growth hormone secretagogues such as GHRP-6 and hexarelin, ipamorelin has been reported to produce less stimulation of adrenocorticotropic hormone, cortisol, and prolactin in animal and early human studies. This selectivity is usually attributed to differences in receptor subtype interactions and to the tissue distribution of the receptor. Effects on appetite appear weaker than those of ghrelin itself, although the supporting evidence base is small. Whether these differences produce a distinct clinical profile remains an open question, since controlled human trials are limited.
Ipamorelin is a synthetic pentapeptide first described in the 1990s by researchers at Novo Nordisk during a program to develop selective growth hormone secretagogues. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, incorporating two non-natural residues, alpha-aminoisobutyric acid and D-2-naphthylalanine. The C-terminus is amidated, and the material is supplied as a white lyophilized powder. The molecular formula is C38H49N9O5 and the monoisotopic mass is approximately 711.85 daltons. The short chain and modified residues give it greater resistance to enzymatic degradation than many larger peptide hormones.
14 October – David Lammy becomes the first UK Foreign Secretary to attend a meeting of EU foreign ministers since Brexit as part of Labour's wish to "reset" the UK's relationship with the EU. Monarchists in Australia have criticised a decision by the country's state premieres to be absent from a reception held by Charles III when he visits the country later in the month, describing it as a snub. 16 October – The Assisted Dying Bill is introduced into Parliament, criticised by Archbishop of Canterbury Justin Welby as "dangerous" and a "slippery slope". 17 October – Former Conservative MP Craig Mackinlay is formally introduced into the House of Lords as Lord Mackinlay of Richborough. Now affectionately known as the 'bionic lord', he is the first quadruple amputee to sit in the Lords. 2024 Conservative Party leadership election: Conservative Party leadership candidates Robert Jenrick and Kemi Badenoch take part in a leadership debate on GB News, but Badenoch has turned down an invitation to take part in a Question Time special on BBC One, and a planned online debate organised by The Sun. 18 October – King Charles III and Queen Camilla arrive in Australia for their royal tour, Charles's first visit to the country since becoming King. 10 Downing Street says there will be no apology for the UK's role in the transatlantic slave trade when Charles III and Starmer attend the Commonwealth summit in Samoa. Former Daily Record editor Murray Foote announces he is standing down as chief executive of the SNP after 14 months in the post.
Large stockpiles of weapons-grade plutonium were built up by both the Soviet Union and the United States during the Cold War. The U.S. reactors at Hanford and the Savannah River Site in South Carolina produced 103 tonnes, and an estimated 170 tonnes of military-grade plutonium was produced in the USSR. Each year about 20 tonnes of the element is still produced as a by-product of the nuclear power industry. As much as 1000 tonnes of plutonium may be in storage with more than 200 tonnes of that either inside or extracted from nuclear weapons. SIPRI estimated the world plutonium stockpile in 2007 as about 500 tonnes, divided equally between weapon and civilian stocks. Radioactive contamination at the Rocky Flats Plant primarily resulted from two major plutonium fires in 1957 and 1969. Much lower concentrations of radioactive isotopes were released throughout the operational life of the plant from 1952 to 1992. Prevailing winds from the plant carried airborne contamination south and east, into populated areas northwest of Denver. The contamination of the Denver area by plutonium from the fires and other sources was not publicly reported until the 1970s. According to a 1972 study, co-authored by Edward Martell, "In the more densely populated areas of Denver, the Pu contamination level in surface soils is several times fallout", and the plutonium contamination "just east of the Rocky Flats plant ranges up to hundreds of times that from nuclear tests".
== Clinical significance == Mice with mutant carboxypeptidase E, Cpefat, display endocrine disorders like obesity and infertility. In some strains of mice, the fat mutation also causes hyperproinsulinemia in adult male mice, but this is not found in all strains of mice. The obesity and infertility in the Cpefat mice develop with age; young mice (<8 weeks of age) are fertile and have normal body weight. Peptide processing in Cpefat mice is impaired, with a large accumulation of peptides with C-terminal lysine and/or arginine extensions. Levels of the mature forms of peptides are generally reduced in these mice, but not eliminated. It is thought that a related enzyme (carboxypeptidase D) also contributes to neuropeptide processing and gives rise to the mature peptides in the Cpefat mice. Mutations in the CPE gene are not common within the human population, but have been identified. One patient with extreme obesity (Body Mass Index >50) was found to have a mutation that deleted nearly the entire CPE gene. This patient had intellectual disability (inability to read or write) and had abnormal glucose homeostasis, similar to mice lacking CPE activity. In obesity, high levels of circulating free fatty acids have been reported to cause a decrease in the amount of carboxypeptidase E protein in pancreatic beta-cells, leading to beta-cell dysfunction (hyperproinsulinemia) and increased beta-cell apoptosis (via an increase in ER stress).
Pedro Cuatrecasas (27 September 1936 – 19 March 2025) was a Spanish-born American biochemist and academic who was an adjunct professor of Pharmacology & Medicine at the University of California San Diego.
Sources: en.wikipedia.org
== Adverse effects == Common side effects include low blood pressure, cough, hyperkalemia, headache, dizziness, fatigue, nausea, and kidney impairment. The main adverse effects of ACE inhibition can be understood from their pharmacological action. The other reported adverse effects are liver problems and effects on the fetus. Kidney problems may occur with all ACE inhibitors that directly follows from their mechanism of action. However, the decrease may be significant in conditions of pre-existing decreased renal perfusions, such as renal artery stenosis, heart failure, polycystic kidney disease, or volume depletion. In these patients, the maintenance of GFR depends on angiotensin-II-dependent efferent vasomotor tone. Therefore, renal function should be closely monitored over the first few days after initiation of treatment with ACE inhibitor in patients with decreased renal perfusion. Generally, a moderate reduction in renal function (no greater than 30% rise in serum creatinine which stabilizes within 2–4 weeks) is considered acceptable as part of the therapeutic effect. Reduced GFR is especially a problem if the patient is concomitantly taking an NSAID and a diuretic. When the three drugs are taken together, the risk of developing renal failure is significantly increased. Hyperkalemia, or high blood potassium, is a common adverse effect of treatment in 2% to 6% of patients. Suppression of angiotensin II leads to a decrease in aldosterone levels. Since aldosterone is responsible for increasing the excretion of potassium, ACE inhibitors can cause retention of potassium.
=== Germany === Germany had two reasons to support Russia. Firstly, it desired to draw Russia's attention to the east, away from itself. Secondly, to enlist Russia's support in establishing German territorial concessions in China. Germany hoped that supporting Russia would encourage Russia, in turn, to support Germany's colonial ambitions, which were especially vexed since Germany had only recently formed itself into a unified nation and had arrived late in the colonial "game". Germany herself had been recently converted to a colonies-seeking Power after the deposition of Bismarck as too conservative and traditionalist by the pro-Weltpolitik and blue-water navy policy Kaiser Wilhelm II, who was also by many accounts taken by a profound anti-Asian racial attitude, fearing the rise of Japanese domination years later after Russia’s defeat in 1905 in the Russo-Japanese War.
=== Eddy's debt to Quimby === Eddy's debt to Phineas Parkhurst Quimby became the "single most controversial issue" of her life, according to Gillian Gill. Quimby was not the only source Eddy stood accused of having copied; Ernest Sutherland Bates and John V. Dittemore, Bryan Wilson, Charles S. Braden and Martin Gardner identified several texts she had used without attribution. For example, an open letter from Eddy to the church, dated September 1895 and published in Eddy's Miscellaneous Writings 1883–1896 (1897), is almost identical to Hugh Blair's essay "The Man of Integrity," published in Lindley Murray's The English Reader (1799). Eddy acknowledged Quimby's influence in her early years. When a prospective student asked in 1871 whether her methods had been used before, she replied:
== Spinal cord exit == Most motor pathways originate in the motor cortex of the brain. Signals run down the brainstem and spinal cord ipsilaterally, on the same side, and exit the spinal cord at the ventral horn of the spinal cord on either side. Motor nerves communicate with the muscle cells they innervate through motor neurons once they exit the brain or spinal cord.
=== Treating avascular necrosis === When treating avascular necrosis of the bone in people with sickle cell disease, treatment aims to reduce or stop the pain and maintain joint mobility. Treatment options include resting the joint, physical therapy, pain-relief medicine, joint-replacement surgery, or bone grafting.
Sources: en.wikipedia.org
He was highly praised for his debut season with Melbourne with the Australian Associated Press' Michael Ramsey writing Hibberd was almost certainly Melbourne's most valuable addition. The Herald Sun's Rebecca Williams and AFL Media's Ben Guthrie furthered this notion by stating he had proven to be one of the top recruits in the league. In addition, The Age reporter, Anthony Colangelo, said Hibberd was one of "Melbourne's best and most important players in their charge up the ladder." His season was rewarded with his first All-Australian selection, where he was named in the back pocket, he was one of three Melbourne nominees for the Leigh Matthews Trophy, and was named in AFL Media's team of the week a further three times after his debut for Melbourne. Despite being one of the favourites to win the best and fairest at Melbourne, he ultimately finished sixth in the award. He received international honours at the end of the season when he represented Australia in the International Rules Series against Ireland in November.
Observe the value of the friction factor for laminar flow at a Reynolds number of 1000. If the value of the friction factor is 0.064, then the Darcy friction factor is plotted in the Moody diagram. Note that the nonzero digits in 0.064 are the numerator in the formula for the laminar Darcy friction factor: fD = 64/Re. If the value of the friction factor is 0.016, then the Fanning friction factor is plotted in the Moody diagram. Note that the nonzero digits in 0.016 are the numerator in the formula for the laminar Fanning friction factor: f = 16/Re. The procedure above is similar for any available Reynolds number that is an integer power of ten. It is not necessary to remember the value 1000 for this procedure—only that an integer power of ten is of interest for this purpose.
== Marketing controversies == Exaggerated claims about the health benefits of goji berry and derived products have triggered strong reactions from government regulatory agencies. In 2019–2020, the U.S. Food and Drug Administration (FDA) placed two goji product distributors on notice with warning letters about unproven therapeutic benefits. The advertisers' statements were in violation of the United States Food, Drug and Cosmetic Act [21 USC/321 (g)(1)] because they "establish[ed] the product as a drug intended for use in the cure, mitigation, treatment, or prevention of disease" when goji ingredients have had no such scientific evaluation. Additionally stated by the FDA, the goji products are "not generally recognized as safe and effective for the referenced conditions" and therefore must be treated as a "new drug" under Section 21(p) of the Act. New drugs may not be legally marketed in the United States without prior approval of the FDA. In January 2007, marketing statements for a goji juice product were the subject of an investigative report by consumer advocacy program Marketplace produced by Canadian public broadcaster CBC. In the interview, Earl Mindell (then working for direct-marketing company FreeLife International, Inc.) falsely claimed the Memorial Sloan-Kettering Cancer Center in New York had completed clinical studies showing that use of wolfberry juice would prevent 75% of human breast cancer cases.
Alimentary Pharmacology & Therapeutics is a bimonthly peer-reviewed medical journal concerned with the effects of drugs on the human gastrointestinal and hepato-biliary systems, particularly with relevance to clinical practice. The journal publishes original papers concerned with all aspects of basic and clinical pharmacology, pharmacokinetics, and the therapeutic use of drugs in the alimentary tract including the liver, gall bladder, and pancreas. Its editors are J. M. Rhodes and C. W. Howden.
The soybean, soy bean, or soya bean (Glycine max) is a species of legume native to East Asia, widely grown for its edible bean. Soy is a staple crop, the world's most grown legume, and an important animal feed. Soy is a key food source, owing to its high protein and oil content. Soybean oil is widely used in cooking, as well as in industry. Traditional unfermented food uses of soybeans include edamame, as well as soy milk, from which tofu and tofu skin are made. Fermented soy foods include soy sauce, fermented bean paste, nattō, and tempeh. Fat-free (defatted) soybean meal is a significant and cheap source of protein for animal feeds and many packaged meals. For example, soybean products, such as textured vegetable protein (TVP), are ingredients in many meat and dairy substitutes. Soy-based foods are traditionally associated with East Asian cuisines, and still constitute a major part of East Asian diets, but processed soy products are increasingly used in Western cuisines. Soy was domesticated from the wild soybean (Glycine soja) in north-central China between 6,000 and 9,000 years ago. Brazil and the United States lead the world in modern soy production. The majority of soybeans are genetically modified, usually for either insect, herbicide, or drought resistance. Three-quarters of soy is used to feed livestock, which in turn go to feed humans. Increasing demand for meat has substantially increased soy production since the 1980s, and contributed to deforestation in the Amazon. Soybeans contain significant amounts of phytic acid, dietary minerals, and B vitamins.
Sources: en.wikipedia.org
不是。它属于人工合成的五肽，设计上模拟胃饥饿素受体的部分作用，但不存在于人体天然激素谱中。
生长激素释放激素通过其专用受体起作用，而 ipamorelin 主要作用于胃饥饿素受体。两者可影响生长激素释放，但信号通路和下游效应并不相同。
研究多集中在生长激素释放的急性调节、受体选择性以及不同给药方式下的药代动力学。临床终点研究数量有限，长期结局尚不明确。
肽键在 214 nm 附近有较强吸收，适合检测缺少芳香侧链的短肽。该波长的基线受流动相组成与梯度影响较大。因此流动相与梯度条件需要固定并完整记录。