If you have been reading about GHS-R1a 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 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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。
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 |
Identity and purity are assessed by complementary methods rather than a single test. Reversed-phase high-performance liquid chromatography separates the peptide from related impurities and reports a percentage purity. Mass spectrometry, most often with electrospray ionization, confirms the expected molecular mass and detects sequence-related variants. Amino acid analysis can verify composition, while water content and residual counterion measurements support the mass balance of a batch. Stability studies under accelerated conditions are used to estimate shelf life, though such estimates carry uncertainty for long-term storage.
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.
Triple-decker complexes are composed of three Cp anions and two metal cations in alternating order. The first triple-decker sandwich complex, [Ni2Cp3]+, was reported in 1972. Many examples have been reported subsequently, often with boron-containing rings.
Consuming food prior to taking chlorpromazine orally limits its absorption; likewise, cotreatment with benztropine can also reduce chlorpromazine absorption. Alcohol can also reduce chlorpromazine absorption. Antacids slow chlorpromazine absorption. Lithium and chronic treatment with barbiturates can increase chlorpromazine clearance significantly. Tricyclic antidepressants (TCAs) can decrease chlorpromazine clearance and hence increase chlorpromazine exposure. Cotreatment with CYP1A2 inhibitors like ciprofloxacin, fluvoxamine or vemurafenib can reduce chlorpromazine clearance and hence increase exposure and potentially also adverse effects. Chlorpromazine can also potentiate the CNS depressant effects of drugs like barbiturates, benzodiazepines, opioids, lithium and anesthetics and hence increase the potential for adverse effects such as respiratory depression and sedation. Chlorprozamine is also a moderate inhibitor of CYP2D6 and a substrate for CYP2D6 and hence can inhibit its own metabolism. It can also inhibit the clearance of CYP2D6 substrates such as dextromethorphan, potentiating their effects. Other drugs like codeine and tamoxifen, which require CYP2D6-mediated activation into their respective active metabolites, may have their therapeutic effects attenuated. Likewise, CYP2D6 inhibitors such as paroxetine or fluoxetine can reduce chlorpromazine clearance, increasing serum levels of chlorpromazine and potentially its adverse effects. Chlorpromazine also reduces phenytoin levels and increases valproic acid levels.
Aristotelia chilensis, known as maqui or Chilean wineberry, is a tree species in the Elaeocarpaceae family native to South America in the Valdivian temperate forests of Chile and adjacent regions of southern Argentina. Limited numbers of these trees are cultivated in gardens for their small edible fruits. Wild-harvested fruits are commercially marketed. The species has drawn attention for its forensic potential as it is reported to be among the first plants to grow around pig carcasses, which are experimental substitutes for human corpses, in southern Chile.
== Historiography == Berger, Henry W. ed. A William Appleman Williams Reader (1992). Ferrell, Robert H. Harry S. Truman and the Cold War Revisionists. (2006). 142 pp. excerpt and text search. Fitzpatrick, Sheila. "Russia's Twentieth Century in History and Historiography," The Australian Journal of Politics and History, Vol. 46, 2000. Gardner, Lloyd C. (ed.) Redefining the Past: Essays in Diplomatic History in Honor of William Appleman Williams (1986). Garthoff, Raymond L. "Foreign Intelligence and the Historiography of the Cold War." Journal of Cold War Studies 2004 6(2): 21–56. ISSN 1520-3972 Fulltext: Project MUSE. Isaac, Joel; Bell, Duncan, eds. Uncertain Empire: American History and the Idea of the Cold War (2012) online review by Victoria Hallinan. Kaplan, Lawrence S. American Historians and the Atlantic Alliance, (1991) online edition.. Kort, Michael. The Columbia Guide to the Cold War (1998). Matlock, Jack E. "The End of the Cold War" Harvard International Review, Vol. 23 (2001). Melanson, Richard A. "Revisionism Subdued? Robert James Maddox and the Origins of the Cold War" Political Science Reviewer, Vol. 7 (1977). Melanson, Richard A. Writing History and making Policy: The Cold War, Vietnam, and Revisionism (1983). Olesen, Thorsten B.Ed. The Cold War and the Nordic Countries: Historiography at a Crossroads. Odense: U Southern Denmark Press, 2004. Pp. 194. online review. Stephanson, Anders. American Imperatives: The Cold War and Other Matters, Verso Books, 2025 Suri, Jeremi.
Sources: en.wikipedia.org
In nuclear science a decay chain refers to the predictable series of radioactive disintegrations undergone by the nuclei of certain unstable chemical elements. Radioactive isotopes do not usually decay directly to stable isotopes, but rather into another radioisotope. The isotope produced by this radioactive emission then decays into another, often radioactive isotope. This chain of decays always terminates in a stable isotope, whose nucleus no longer has the surplus of energy necessary to produce another emission of radiation. Such stable isotopes are then said to have reached their ground states. The stages or steps in a decay chain are referred to by their relationship to previous or subsequent stages. Hence, a parent isotope is one that undergoes decay to form a daughter isotope. For example element 92, uranium, has an isotope with 144 neutrons (236U) and it decays into an isotope of element 90, thorium, with 142 neutrons (232Th). The daughter isotope may be stable or it may itself decay to form another daughter isotope. 232Th does this when it decays into radium-228. The daughter of a daughter isotope, such as 228Ra, is sometimes called a granddaughter isotope. 228Ra in turn undergoes a further eight decays and transmutations until a stable isotope, 208Pb, is produced, terminating the decay chain of 236U. The time required for an atom of a parent isotope to decay into its daughter is fundamentally unpredictable and varies widely. For individual nuclei the process is not known to have determinable causes and the time at which it occurs is therefore completely random.
=== Water treatment === Water treatment is any process that improves the quality of water to make it more acceptable for a specific end-use. Membranes can be used to remove particulates from water by either size exclusion or charge separation. In size exclusion, the pores in the membrane are sized such that only particles smaller than the pores can pass through. The pores in the membrane are sized such that only water molecules can pass through, leaving dissolved contaminants behind.
The history of ethanol as a fuel spans several centuries and is marked by a series of significant milestones. Samuel Morey, an American inventor, was the first to produce ethanol by fermenting corn in 1826. However, it was not until the California Gold Rush in the 1850s that ethanol was first used as a fuel in the United States. Rudolf Diesel demonstrated his engine, which could run on vegetable oils and ethanol, in 1895, but the widespread use of petroleum-based diesel engines made ethanol less popular as a fuel. In the 1970s, the oil crisis reignited interest in ethanol, and Brazil became a leader in ethanol production and use. The United States began producing ethanol on a large scale in the 1980s and 1990s as a fuel additive to gasoline, due to government regulations. Today, ethanol continues to be explored as a sustainable and renewable fuel source, with researchers developing new technologies and biomass sources for its production.
=== Modern usage === As part of standard TB chemotherapy, isoniazid is now typically administered alongside at least three other drugs—ethambutol, pyrazinamide, and rifampin—for six to nine months. Isoniazid is also included on the World Health Organization's List of Essential Medicines. The World Health Organization classifies isoniazid as critically important for human medicine.
Rickets, a childhood disease, is characterized by impeded growth and soft, weak, deformed long bones that bend and bow under their weight as children start to walk. Maternal vitamin D deficiency can cause fetal bone defects from before birth and impairment of bone quality after birth. Rickets typically presents between 3 and 18 months of age. This condition can be caused by vitamin D, calcium or phosphorus deficiency. Vitamin D deficiency remains the main cause of rickets among young infants in most countries because breast milk is low in vitamin D, and darker skin, social customs, and climatic conditions can contribute to inadequate sun exposure. A post-weaning Western omnivore diet characterized by high intakes of meat, fish, eggs and vitamin-D–fortified milk is protective, whereas low intakes of those foods and high (unfortified) cereal/grain intake contribute to risk. For young children with rickets, supplementation with vitamin D plus calcium was superior to the vitamin alone for bone healing.
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。