A practical reference on selectivity: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-11-09 and is reviewed periodically as new material appears.
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor type 1a, the same G protein-coupled receptor that binds ghrelin. Receptor activation couples to Gq/11 signaling, raising intracellular calcium through inositol trisphosphate and diacylglycerol, which in turn promotes exocytosis of growth hormone from pituitary somatotroph cells. Ipamorelin binds this receptor with high affinity and shows weak activity at other secretagogue-related targets in vitro. Its action requires the intact receptor and is not reversed by growth hormone-releasing hormone antagonists.
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.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class. It acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. The compound was designed in the 1990s during a search for agents that release growth hormone with fewer off-target hormonal effects than earlier secretagogues. It appears in the research literature under several sequence-based names. Material supplied for laboratory work is normally a lyophilized solid, and it is not marketed as an approved therapeutic in major jurisdictions.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with amidated C-terminus |
| Molecular weight | 711.85 g/mol | Monoisotopic mass |
| Primary receptor | GHS-R1a | Ghrelin receptor, Gq/11 coupled |
| Peptide class | Synthetic pentapeptide | Contains two non-natural residues |
| Reported selectivity | Lower cortisol and prolactin effect | Observed in animal and early human work |
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。
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。
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.
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 that acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. Its sequence incorporates non-natural residues, which slows enzymatic breakdown relative to short native peptides. In laboratory and early clinical work the compound is described as a selective growth hormone secretagogue because it raises growth hormone with comparatively little effect on other pituitary outputs. The degree to which that selectivity holds across species and dosing regimens remains an open question in the published literature.
Signal transduction begins when the peptide binds GHSR-1a on pituitary somatotrophs. The receptor couples to Gq/11 proteins, activating phospholipase C, which cleaves phosphatidylinositol bisphosphate into inositol trisphosphate and diacylglycerol. Inositol trisphosphate releases calcium from intracellular stores, and the resulting rise in cytosolic calcium drives growth hormone vesicle fusion. Concurrent Gs coupling and cyclic AMP elevation have also been reported, and the relative contribution of each arm to the overall secretory response is not fully settled.
Structural features distinguish the molecule from earlier secretagogues. An alpha-aminoisobutyric acid residue near the N-terminus and a D-naphthylalanine substitution increase receptor affinity, while C-terminal amidation improves resistance to exopeptidases. These modifications are associated with reduced stimulation of appetite and of the hypothalamic-pituitary-adrenal axis compared with hexarelin or growth hormone releasing peptide-6. Whether the same profile applies at every dose level studied is a matter of ongoing investigation rather than settled consensus.
Cold seeps and hydrothermal vents of deep oceans are communities that do not rely on photosynthesis for food and energy production. These systems are largely driven by chemosynthetic derived energy. Both systems share common characteristics such as the presence of reduced chemical compounds (H2S and hydrocarbonates), local hypoxia or even anoxia, a high abundance and metabolic activity of bacterial populations, and the production of autochthonous, organic material by chemoautotrophic bacteria. Both hydrothermal vents and cold seeps show highly increased levels of metazoan biomass in association with a low local diversity. This is explained through the presence of dense aggregations of foundation species and epizoic animals living within these aggregations. Community-level comparisons reveal that vent, seep, and organic-fall macrofauna are very distinct in terms of composition at the family level, although they share many dominant taxa among highly sulphidic habitats. However, hydrothermal vents and cold seeps also differ in many ways. Compared to the more stable cold seeps, vents are characterized by locally-high temperatures, strongly fluctuating temperatures, pH, sulfide and oxygen concentrations, often the absence of sediments, a relatively young age, and often-unpredictable conditions, such as waxing and waning of vent fluids or volcanic eruptions. Unlike hydrothermal vents, which are volatile and ephemeral environments, cold seeps emit at a slow and dependable rate.
A vacuum pump is a type of pump device that draws gas particles from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke, and was preceded by the suction pump, which dates to antiquity.
===== MeSH D08.811.913.400 – glycosyltransferases (EC 2.4) ===== MeSH D08.811.913.400.100 – n-acetylhexosaminyltransferases MeSH D08.811.913.400.100.200 – n-acetylgalactosaminyltransferases MeSH D08.811.913.400.100.200.300 – fucosyl galactose alpha-n-acetylgalactosaminyltransferase MeSH D08.811.913.400.100.250 – n-acetylglucosaminyltransferases MeSH D08.811.913.400.450 – hexosyltransferases MeSH D08.811.913.400.450.300 – fucosyltransferases MeSH D08.811.913.400.450.400 – galactosyltransferases MeSH D08.811.913.400.450.400.100 – n-acylsphingosine galactosyltransferase MeSH D08.811.913.400.450.400.450 – beta-n-acetylglucosaminylglycopeptide beta-1,4-galactosyltransferase MeSH D08.811.913.400.450.400.475 – ganglioside galactosyltransferase MeSH D08.811.913.400.450.400.500 – lactose synthase MeSH D08.811.913.400.450.400.500.100 – n-acetyllactosamine synthase MeSH D08.811.913.400.450.460 – glucosyltransferases MeSH D08.811.913.400.450.460.100 – 1,4-alpha-glucan branching enzyme MeSH D08.811.913.400.450.460.200 – chitin synthase MeSH D08.811.913.400.450.460.350 – glycogen debranching enzyme system MeSH D08.811.913.400.450.460.375 – glycogen synthase MeSH D08.811.913.400.450.460.400 – phosphorylases MeSH D08.811.913.400.450.460.400.186 – glycogen phosphorylase MeSH D08.811.913.400.450.460.400.186.061 – glycogen phosphorylase, brain form MeSH D08.811.913.400.450.460.400.186.124 – glycogen phosphorylase, liver form MeSH D08.811.913.400.450.460.400.186.312 – glycogen phosphorylase, muscle form MeSH D08.811.913.400.450.460.400.280 – phosphorylase a MeSH D08.811.913.400.450.460.400.327 – phosphorylase b MeSH D08.811.913.400.450.460.400.374 – starch phosphorylase MeSH D08.811.913.400.450.460.750 – starch synthase MeSH D08.811.913.400.450.480 – glucuronosyltransferase MeSH D08.811.913.400.450.560 – mannosyltransferases MeSH D08.811.913.400.450.780 – peptidoglycan glycosyltransferase MeSH D08.811.913.400.725 – pentosyltransferases MeSH D08.811.913.400.725.100 – adenine phosphoribosyltransferase MeSH D08.811.913.400.725.115 – adp ribose transferases MeSH D08.811.913.400.725.115.180 – cholera toxin MeSH D08.811.913.400.725.115.220 – diphtheria toxin MeSH D08.811.913.400.725.115.660 – nad+ nucleosidase MeSH D08.811.913.400.725.115.660.060 – adp-ribosyl cyclase MeSH D08.811.913.400.725.115.680 – pertussis toxin MeSH D08.811.913.400.725.115.690 – poly(adp-ribose) polymerases MeSH D08.811.913.400.725.115.690.840 – tankyrases MeSH D08.811.913.400.725.115.845 – sirtuins MeSH D08.811.913.400.725.130 – amidophosphoribosyltransferase MeSH D08.811.913.400.725.160 – anthranilate phosphoribosyltransferase MeSH D08.811.913.400.725.200 – ATP phosphoribosyltransferase MeSH D08.811.913.400.725.450 – hypoxanthine phosphoribosyltransferase MeSH D08.811.913.400.725.700 – orotate phosphoribosyltransferase MeSH D08.811.913.400.725.800 – purine-nucleoside phosphorylase MeSH D08.811.913.400.725.900 – thymidine phosphorylase MeSH D08.811.913.400.725.950 – uridine phosphorylase MeSH D08.811.913.400.800 – sialyltransferases
Sources: en.wikipedia.org
In 2012, the US Presidential Commission for the Study of Bioethical Issues reported that existing privacy legislation for DNA sequencing data such as GINA and the Health Insurance Portability and Accountability Act were insufficient, noting that whole-genome sequencing data was particularly sensitive, as it could be used to identify not only the individual from which the data was created, but also their relatives. In most of the United States, DNA that is "abandoned", such as that found on a licked stamp or envelope, coffee cup, cigarette, chewing gum, household trash, or hair that has fallen on a public sidewalk, may legally be collected and sequenced by anyone, including the police, private investigators, political opponents, or people involved in paternity disputes. As of 2013, eleven states have laws that can be interpreted to prohibit "DNA theft". Ethical issues have also been raised by the increasing use of genetic variation screening, both in newborns, and in adults by companies such as 23andMe. It has been asserted that screening for genetic variations can be harmful, increasing anxiety in individuals who have been found to have an increased risk of disease. For example, in one case noted in Time, doctors screening an ill baby for genetic variants chose not to inform the parents of an unrelated variant linked to dementia due to the harm it would cause to the parents. However, a 2011 study in The New England Journal of Medicine has shown that individuals undergoing disease risk profiling did not show increased levels of anxiety.
The sequence of a gene can be altered in a number of ways. Gene mutations have varying effects on health depending on where they occur and whether they alter the function of essential proteins. Mutations in the structure of genes can be classified into several types.
Metroglas (Switzerland) manufactures electrochemical and optical sensors for laboratory and process analysis. Metrohm Process Analytics (Netherlands) develops and manufactures online analyzers for the process industry. Metrohm Autolab (Netherlands) develops modular electrochemical measuring instruments, especially for spectroelectrochemistry, corrosion, and battery research. Metrohm DropSens (Spain) produces tools for electrochemical analysis, especially screen-printed electrodes and portable electrochemical instruments. Innovative Photonic Solutions (USA) develops stabilized laser sources for Raman spectroscopy. Metrohm Spectro (USA) manufactures Raman instruments and components, including lasers and high-performance semiconductor diode light source systems. As of 2021, the company generated revenue of more than 400 million Swiss francs. As of 2024, Metrohm employs around 3,200 people worldwide, including approximately 700 at its headquarters in Herisau.
Watson was retrospectively ruled ineligible for the award by the commission, and the medal then awarded to the next-highest vote-getters, Richmond's Trent Cotchin and then-Hawthorn player Sam Mitchell (who had just been traded to the West Coast Eagles at the time), under the normal rules regarding ineligible players in Brownlow Medal counts. Watson had pre-empted the decision by announcing on 11 November 2016 that he would hand back the medal.
Sources: en.wikipedia.org
== Applications == TMU is miscible with a variety of organic compounds, including acids (e.g. acetic acid), bases (e.g. pyridine), and organic substances (e.g. ε-caprolactam, benzoic acid). TMU can also dissolve some inorganic salts such as silver nitrate and sodium iodide. TMU is often used in place of hexamethylphosphoramide (HMPA), which is a suspected carcinogen. TMU is suitable as a reaction medium for the polymerization of aromatic diacid chlorides (such as isophthalic acid) and aromatic diamines (such as 1,3-diaminobenzene (m-phenylenediamine)) to aramids such as poly (m-phenylene isophthalamide) (Nomex) The polymerization of 4-amino benzoic acid chloride hydrochloride in TMU provides isotropic viscous solutions of poly(p-benzamide) (PPB), which can be directly spun into fibers.
Indeed, at least four people have died in the course of either preparation for or institution of bone marrow transplantation for EB, out of only a small group of patients treated so far. The mechanism of action of this therapy is unclear as hematopoietic stem cells are not thought to contribute to epithelial lineages. Rather, it is speculated that cross-correction from tissue-resident graft-derived immune cells contributes to the observed clinical benefit. A pilot study performed in 2015 suggests that systemic granulocyte-colony stimulating factor (G-CSF) may promote increased wound healing in people with dystrophic EB. Transplanting skin derived from genetically modified stem cells onto the wound surfaces has been studied with a report of improvements in one person. A 2017 clinical trial with male RDEB (recessive dystrophic EB) patients conducted successful grafting of type VII gene corrected keratinocytes (COL7A1 gene correction using retrovirus transduction), without any serious adverse effects. Type VII collage formation was observed at the dermis-epidermis junction in significant amounts. A 2020 study demonstrated the safe allogenic grafting of acellular dermal matrix/scaffolds in EB patients without any observed infection or necrosis and instead noted fewer required dressing changes, promoted wound healing, pain reduction, and an overall improvement in the quality of life of the patients. In 2022, a pharmaceutical gel made out of birch bark extract from Betula pendula and Betula pubescens was approved by the European Union as a treatment for epidermolysis bullosa.
== Other animals == Bowed tendon is a term for form of tendinitis (inflammation) and tendinosis (degeneration) most commonly seen in the superficial digital flexor tendon in the front leg of horses. Mesenchymal stem cells, derived from a horse's bone marrow or fat, can be used for tendon repair in horses.
Sources: en.wikipedia.org
It is a synthetic pentapeptide belonging to the growth hormone secretagogue family. Its principal characterized target is the ghrelin receptor, also called GHS-R1a. The molecule contains non-natural amino acids and an amidated C-terminus.
Both act at the same G protein-coupled receptor, but ipamorelin is a short synthetic peptide with modified residues rather than the natural 28-amino-acid hormone. Reports describe weaker effects on appetite and on cortisol or prolactin release than those seen with ghrelin. Its resistance to enzymatic breakdown also differs from that of the natural ligand.
Receptor binding and downstream calcium signaling are well characterized in cell-based systems. Effects measured in whole organisms are less consistent across studies and species. The extent to which selective receptor behavior drives the observed hormonal profile is still debated.
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.