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 2025-12-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
Reversed-phase high-performance liquid chromatography is the standard method for purity assessment, most often on a C18 column with a water and acetonitrile gradient and trifluoroacetic acid or formic acid as an ion-pairing agent. Mass spectrometry by electrospray or matrix-assisted laser desorption confirms the expected mass and reveals truncated or modified sequences. Amino acid analysis and sequencing provide orthogonal structural evidence. Typical impurities include deletion sequences, oxidized products, and dimeric species. Detection wavelength, usually 214 or 220 nanometers, should be reported because response factors differ between peptides.
Purity is normally reported as a percentage of total peak area, a figure that does not account for water content, residual solvents, or counterions. Trifluoroacetate and acetate are the most frequent counterions in lyophilized peptides, and they shift the true peptide content away from the mass of the powder. A separate quantitative assay is therefore needed to state content accurately. Certificates of analysis often omit these details, which makes batch-to-batch comparison difficult and limits conclusions drawn when results from different suppliers are compared.
Lyophilized material is generally held at minus twenty degrees Celsius or lower, protected from moisture and light. Repeated excursions to room temperature cause condensation inside the vial and gradual moisture uptake, both of which shorten shelf life. Containers should be allowed to equilibrate before opening so that water does not condense on the solid. Dividing a batch into single-use aliquots reduces freeze-thaw cycling. Solid peptide handled this way is usually considered stable for months to years, while the same material in solution degrades on a much shorter timescale.
| 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 other secretagogues such as GHRP-2, GHRP-6, and hexarelin, ipamorelin is described as more selective. Published animal work reports little or no increase in adrenocorticotropic hormone, cortisol, or prolactin at doses that release growth hormone. This selectivity is the property most often cited in the research literature. Whether the same profile holds across species and dosing schedules remains an open question, since human data are limited and come largely from small studies.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue family. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, and its molecular mass is approximately 711.9 daltons. The compound was described in the late 1990s by researchers seeking molecules that release growth hormone with fewer side effects than earlier secretagogues. It is a laboratory and research compound, not an approved medicine in most jurisdictions.
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Researchers at a pharmaceutical company first described it in the 1990s while screening small peptides for growth hormone releasing activity. Its chain contains five amino acid residues, two of which are non-natural building blocks, including 2-aminoisobutyric acid and a naphthylalanine derivative. The molecule was designed to act at the ghrelin receptor while avoiding several effects observed with earlier secretagogues.
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.
Graphene nanoribbons ("nanostripes" in the "zig-zag"/"zigzag" orientation), at low temperatures, show spin-polarized metallic edge currents, which also suggests applications in the new field of spintronics. (In the "armchair" orientation, the edges behave like semiconductors.)
James Lamar Wittliff (born June 15, 1938) also known as Jim Wittliff, is an American Biochemist and Professor Emeritus of Biochemistry & Molecular Genetics at the University of Louisville. He was Chairman of the Department of Biochemistry at the University of Louisville School of Medicine and Dentistry from 1976-1983. Wittliff's laboratory was designated the National Reference Facility by the National Cancer Institute for performing quality assurance surveys of receptor biomarker testing in breast cancers for cooperative clinical trial groups in the United States and Canada. He is the co-developer with NEN/DuPont of the 1st FDA approved tests for quantifying levels of estrogen and progestin receptor proteins.
This being the reason for seeing mass decay between 660 °C and 710 °C. Differences in differential thermogram (DTG) peaks for TLW were compared to TSW. TLW had four distinctive peaks at 87, 195, 265, and 306 °C whereas TSW had two major drop offs at 200 and 306 °C with one spike in between. The four peaks indicated that TLW contains more diverse types of additives than TSW. The residual mass percentage between TLW and TSW was further compared, where the residual mass in TSW was less than that of TLW for both CO2 and N2 environments concluding that TSW has higher quantities of additives than TLW.
== Indication == Trimecaine has two main application fields. The first one is local anesthesia (topical, infiltrational, topical mucosal and inhalational, spinal and Bier's intravenous). It is used in concentrations 0.4 up to 4%, in some cases (e.g. in stomatology) in mixtures with adrenaline. The other field is prophylaxis and therapy of ventriculous arrhythmia on myocardial infarction and in cardiosurgery. It is used also for prophylaxis of sympathetic reaction during tracheal intubations.
Sources: en.wikipedia.org
A major cause for the ineffectiveness of current chemotherapy treatments is multiple drug resistance which can arise from several mechanisms. Nanoparticles can provide a means to overcome MDR. In general, when using a targeting agent to deliver nanocarriers to cancer cells, it is imperative that the agent binds with high selectivity to molecules that are uniquely expressed on the cell surface. Hence NPs can be designed with proteins that specifically detect drug resistant cells with overexpressed transporter proteins on their surface. A pitfall of the commonly used nano-drug delivery systems is that free drugs that are released from the nanocarriers into the cytosol get exposed to the MDR transporters once again, and are exported. To solve this, 8 nm nanocrystalline silver particles were modified by the addition of trans-activating transcriptional activator (TAT), derived from the HIV-1 virus, which acts as a cell-penetrating peptide (CPP). Generally, AgNP effectiveness is limited due to the lack of efficient cellular uptake; however, CPP-modification has become one of the most efficient methods for improving intracellular delivery of nanoparticles. Once ingested, the export of the AgNP is prevented based on a size exclusion. The concept is simple: the nanoparticles are too large to be effluxed by the MDR transporters, because the efflux function is strictly subjected to the size of its substrates, which is generally limited to a range of 300-2000 Da. Thereby the nanoparticulates remain insusceptible to the efflux, providing a means to accumulate in high concentrations.
The first Soviet development of artillery rockets was in 1921 when the Soviet military sanctioned the Gas Dynamics Laboratory, a small research laboratory to explore solid-fuel rockets, led by Nikolai Tikhomirov, who had begun studying solid and liquid-fueled rockets in 1894, and obtained a patent in 1915 for "self-propelled aerial and water-surface mines. The first test-firing of a solid fuel rocket was carried out in 1928. Further development was carried out in the 1930s by the Group for the Study of Reactive Motion (GIRD), where Soviet rocket pioneers Sergey Korolev, Friedrich Zander, Mikhail Tikhonravov and Leonid Dushkin launched GIRD-X, the first Soviet liquid-fueled rocket in 1933. In 1933 the two design bureaus were combined into the Reactive Scientific Research Institute and produced the RP-318, the USSR's first rocket-powered aircraft and the RS-82 and RS-132 missiles, which became the basis for the Katyusha multiple rocket launcher, During the 1930s Soviet rocket technology was comparable to Germany's, but Joseph Stalin's Great Purge from 1936 to 1938 severely damaged its progress. In 1945 the Soviets captured several key Nazi German A-4 (V-2) rocket production facilities, and also gained the services of some German scientists and engineers related to the project. A-4s were assembled and studied and the experience derived from assembling and launching A4 rockets was directly applied to the Soviet copy, called the R-1, with NII-88 chief designer Sergei Korolev overseeing the R-1's development., The R-1 entered into service in the Soviet Army on 28 November 1950.
=== Dried flour === In South-west Nigeria, unripe plantains are also dried and ground into flour which is referred to as Elubo Ogede. it is considered as a healthy and nutritious food among the Yoruba. In southern India, dried plantain powder is mixed with a little bit of fennel seed powder and boiled in milk or water to make baby food to feed babies until they are one year old.
=== Contamination === Melamine-formaldehyde resin tableware was evaluated by the Taiwan Consumers' Foundation to have 20 parts per million of free melamine that could migrate out of the plastic into acidic foods if held at 160 °F (71 °C) for two hours, such as if food were kept heated in contact with it in an oven.
Laccases (EC 1.10.3.2) are multicopper oxidases found in plants, fungi, and bacteria. Laccases oxidize a variety of phenolic substrates, performing one-electron oxidations, leading to crosslinking. For example, laccases play a role in the formation of lignin by promoting the oxidative coupling of monolignols, a family of naturally occurring phenols. Other laccases, such as those produced by the fungus Pleurotus ostreatus, play a role in the degradation of lignin, and can therefore be classed as lignin-modifying enzymes. Other laccases produced by fungi can facilitate the biosynthesis of melanin pigments. Laccases catalyze ring cleavage of aromatic compounds. Laccase was first studied by Hikorokuro Yoshida in 1883 and then by Gabriel Bertrand in 1894 in the sap of the Japanese lacquer tree, where it helps to form lacquer, hence the name laccase.
Sources: en.wikipedia.org
== Metabolism == Metabolic activation is required for PhIP to function as a mutagen. Therefore, the cancer risk posed by PhIP depends on the extent at which PhIP is metabolized. After absorption, PhIP is converted to a genotoxic metabolite in the liver by Phase I enzyme N-oxidation by Cytochrome P-450 1A2 (CYP1A2). PhIP can be further metabolized into a more potent metabolite through O-acetylation by hepatic or colonic N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2), or by sulfotransferases. However, PhIP may also undergo a detoxification pathway through Phase II conjugation reaction via UDP-glucuronosyltransferases (UGTs) to form N-glucuronide conjugates. PhIP's nitrenium ion intermediate is a powerful electrophile that has propensity to form C-8 guanine adducts with the DNA. In addition, some of these metabolic enzymes are inducible and have polymorphic variation. CYP1A2 displays a 40-fold variation in expression among humans and can be induced by smoking, diet, and chronic hepatitis. The expression of UGTs also displays inducibility; however, NATs do not. Individuals can be classified as either rapid or slow N-oxidizers and O-acetylators by assessing CYP1A2 and NAT2 activities. Individuals with the rapid phenotype of either CYP1A2 or NAT2 metabolize PhIP more effectively and are therefore at greater risk of PhIP's carcinogenic metabolite and could be at a higher risk of cancer.
Manuel Antonio Noriega Moreno ( mahn-WEL NOR-ee-AY-gə; Spanish: [maˈnwel noˈɾjeɣa]; February 11, 1934 – May 29, 2017) was a Panamanian military officer and dictator who was the de facto ruler of Panama from 1983 to 1989. He never officially served as president of Panama, instead ruling as an unelected military dictator through puppet presidents. Amassing a personal fortune through drug trafficking operations by the Panamanian military, Noriega had longstanding ties with American intelligence agencies before the United States invasion of Panama removed him from power. Born in Panama City to a poor pardo family, Noriega studied at the Chorrillos Military School in Lima and at the School of the Americas. He became an officer in the Panamanian army, and rose through the ranks in alliance with Omar Torrijos. In 1968, Torrijos overthrew President Arnulfo Arias in a coup. Noriega became chief of military intelligence in Torrijos's government and, after Torrijos's death in 1981, consolidated power to become Panama's de facto ruler in 1983. Beginning in the 1950s, Noriega worked with U.S. intelligence agencies, and became one of the Central Intelligence Agency's most valued intelligence sources. He also served as a conduit for illicit weapons, military equipment, and cash destined for U.S.-backed forces throughout Latin America. Noriega's relationship with the U.S. deteriorated in the late 1980s after the murder of Hugo Spadafora and the forced resignation of President Nicolás Ardito Barletta.
== Metabolism == Urobilin is generated from the degradation of heme, which is first degraded through biliverdin to bilirubin. Bilirubin is then excreted as bile, which is further degraded by microbes present in the large intestine to urobilinogen. The enzyme responsible for the degradation is bilirubin reductase, which was identified in 2024. Some of this remains in the large intestine, and its conversion to stercobilin gives feces their brown color. Some is reabsorbed into the bloodstream and then delivered to the kidneys. When urobilinogen is exposed to air, it is oxidized to urobilin, which has a yellow color.
PSSM is most prevalent in American Quarter Horses and their related breeds (Paint horse, Appaloosa, Appendix Quarter Horse), Draft horse breeds (especially Belgian Draft and Percherons), and Warmblood breeds. The Belgian Draft been shown to have a 36% prevalence of PSSM. Other breeds that have been diagnosed with PSSM include the Arabian, Lipizzaner, Morgan, Mustang, Peruvian Paso, Rocky Mountain Horse, Standardbred, Tennessee Walking Horse, Thoroughbred, and National Show Horse. It has been suggested that the GSY1 mutation provided some benefit to hard working animals with poor-quality diets, and is now damaging members of those "thrifty" breeds that are managed with moderate to low levels of work and diets high in non-structural carbohydrates. PSSM Type 1 (homozygous or heterozygous for the GSY1 mutation) is more common in Quarter Horses and their related breeds, and draft breeds, while PSSM Type 2 (negative for the GSY1 mutation) is more commonly seen in other breeds, including warmbloods. There is no sex predilection to the disease.
==== 2600–2699 ==== Greater Manchester Ambulance Service National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2600) Lancashire Ambulance Service National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2601) Tameside and Glossop Acute Services National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2602) Darlington Memorial Hospital National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2603) Bolton Hospitals National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2604) Priority Healthcare Wearside National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2605) Community Health Care Service (North Derbyshire) National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2606) Wirral Community Healthcare National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2607) North Lakeland Healthcare National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2608) North Downs Community Health National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2609) South Durham Health Care National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2610) Salford Community Health Care National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2611) Community Health Care: North Durham National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2612) Kingston and District Community National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2613) North Durham Acute Hospitals National Health Service Trust (Establishment) Order 1993 (S.I.
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。
It is reported as the percentage of total peak area in a reversed-phase chromatogram. That number does not reflect water content, residual solvents, or counterions. The actual peptide content is therefore lower than the stated purity figure suggests.