Everything below concerns secretagogue. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
在机制层面,ipamorelin 与生长激素促分泌受体 1a 型结合,该受体也介导胃饥饿素的多种效应。受体激活后,细胞内信号促进生长激素从垂体前叶释放。由于对促肾上腺皮质激素和皮质醇的刺激较弱,它被视为选择性较高的促分泌剂。这种选择性在动物模型和少量人体研究中被观察到,但人体数据仍然有限。
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。
Activity is mediated mainly through the growth hormone secretagogue receptor, now generally called the ghrelin receptor or GHS-R1a. Binding at this G-protein-coupled receptor triggers phospholipase C signaling, calcium mobilization, and release of growth hormone from pituitary somatotrophs. Reports describe less pronounced stimulation of adrenocorticotropic hormone and prolactin compared with earlier secretagogues such as hexarelin or GHRP-6. Selectivity figures vary between assay systems, so the degree of separation from other secretagogues is an area of ongoing comparison rather than a fixed constant.
In animal and early human studies, ipamorelin produces pulsatile growth hormone release and a secondary rise in insulin-like growth factor 1. The magnitude and duration of that rise depend on route, sampling schedule, and the baseline endocrine state of the subject. Whether repeated exposure alters the response over time is not firmly settled, since some reports describe stable pulsatility while others note attenuation. Most published data come from small samples, which limits the strength of any general claim about long-term behavior.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, a structure that differs from natural ghrelin in length and in the presence of non-natural amino acid residues. Early laboratory work described it as a comparatively selective agent that stimulates growth hormone release with limited effect on other pituitary hormones. The compound is supplied as a lyophilized solid for research use and has no identified natural source in the body.
| 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 |
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.
Common solvents for laboratory work include water, buffered saline, and dimethyl sulfoxide. Once dissolved, the peptide is exposed to hydrolysis and oxidation, and alkaline conditions accelerate breakdown. Low-binding plasticware and the addition of a carrier protein reduce losses to container surfaces, which can otherwise be substantial at low concentrations. Solutions are typically kept cold and used within days. Investigators working with the compound generally prepare fresh working dilutions rather than storing dilute stocks, and they avoid repeated warming of the same vial.
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。
Aphids and other hemipteran insects secrete a sweet liquid called honeydew, when they feed on plant sap. The sugars in honeydew are a high-energy food source, which many ant species collect. In some cases, the aphids secrete the honeydew in response to ants tapping them with their antennae. The ants in turn keep predators away from the aphids and will move them from one feeding location to another. When migrating to a new area, many colonies will take the aphids with them, to ensure a continued supply of honeydew. Ants also tend mealybugs to harvest their honeydew. Mealybugs may become a serious pest of pineapples if ants are present to protect mealybugs from their natural enemies. Myrmecophilous (ant-loving) caterpillars of the butterfly family Lycaenidae (e.g., blues, coppers, or hairstreaks) are herded by the ants, led to feeding areas in the daytime, and brought inside the ants' nest at night. The caterpillars have a gland which secretes honeydew when the ants massage them. The chemicals in the secretions of Arhopala japonica alter the behavior of attendant Pristomyrmex punctatus workers, making them less aggressive and stationary. The relationship, formerly characterized as "mutualistic", is now considered as possibly a case of the ants being parasitically manipulated by the caterpillars. Some caterpillars produce vibrations and sounds that are perceived by the ants. A similar adaptation can be seen in grizzled skipper butterflies that emit vibrations by expanding their wings in order to communicate with ants, which are natural predators of these butterflies.
The substance is quickly and almost completely absorbed from the gut. Highest blood plasma concentrations are reached after two hours. It is bound to plasma proteins to 80–90%. Concentrations in the synovial fluid and membranes, muscle and bone are higher than in the blood. Apart from the active metabolite indometacin, a number of inactive metabolites are found after application of acemetacin: the O-desmethyl-, des-4-chlorobenzoyl-, and O-desmethyl-des-4-chlorobenzoyl derivatives of both indometacin and acemetacin, as well as all of these substances' glucuronides (mediated at least partly by the enzyme UGT2B7). Elimination half-life is 4.5±2.8 hours (in some individuals up to 16 hours) under steady state conditions. 40% are eliminated via the kidney, and 50% via the faeces.
==== Excitation-contraction coupling ==== Excitation contraction coupling is the process by which a muscular action potential in the muscle fiber causes the myofibrils to contract. This process relies on a direct coupling between the sarcoplasmic reticulum calcium release channel RYR1 (ryanodine receptor 1), and voltage-gated L-type calcium channels (identified as dihydropyridine receptors, DHPRs). DHPRs are located on the sarcolemma (which includes the surface sarcolemma and the transverse tubules), while the RyRs reside across the SR membrane. The close apposition of a transverse tubule and two SR regions containing RyRs is described as a triad and is predominantly where excitation–contraction coupling takes place. Excitation–contraction coupling occurs when depolarization of skeletal muscle cell results in a muscle action potential, which spreads across the cell surface and into the muscle fiber's network of T-tubules, thereby depolarizing the inner portion of the muscle fiber. Depolarization of the inner portions activates dihydropyridine receptors in the terminal cisternae, which are close to ryanodine receptors in the adjacent sarcoplasmic reticulum. The activated dihydropyridine receptors physically interact with ryanodine receptors to activate them via foot processes (involving conformational changes that allosterically activates the ryanodine receptors). As the ryanodine receptors open, Ca2+ is released from the sarcoplasmic reticulum into the local junctional space and diffuses into the bulk cytoplasm to cause a calcium spark.
French waxing leaves a small amount of hair on either side of the labia or a strip directly above and in line with the pudendal cleft called a landing strip. Islam teaching includes Muslim hygienical jurisprudence a practice of which is the removal of pubic hair.
Sources: en.wikipedia.org
Nefopam by mouth and cannabis are not recommended as of 2012, as the risks of use appear to be greater than the benefits. Limited evidence suggests the use of weak oral opioids, but the adverse effects may outweigh the benefits. Alternatively, physical therapy has been tested and shown as an effective aid in reducing pain in patients with RA. As most RA is detected early and treated aggressively, physical therapy plays more of a preventive and compensatory role, aiding in pain management alongside regular rheumatic therapy.
Many birds actively defend a territory from others of the same species during the breeding season; maintenance of territories protects the food source for their chicks. Species that are unable to defend feeding territories, such as seabirds and swifts, often breed in colonies instead; this is thought to offer protection from predators. Colonial breeders defend small nesting sites, and competition between and within species for nesting sites can be intense. All birds lay amniotic eggs with hard shells made mostly of calcium carbonate. Hole and burrow nesting species tend to lay white or pale eggs, while open nesters lay camouflaged eggs. There are many exceptions to this pattern, however; the ground-nesting nightjars have pale eggs, and camouflage is instead provided by their plumage. Species that are victims of brood parasites have varying egg colours to improve the chances of spotting a parasite's egg, which forces female parasites to match their eggs to those of their hosts.
=== Controversies === In January 2025, Paetongtarn revealed that she had nearly been victimized by a scam using a message in a voice sounding identical to another world leader whom she did not disclose in which the caller was asking for donations. On 24 March 2025, a no-confidence motion was filed against Paetongtarn by Leader of the Opposition Natthaphong Ruengpanyawut, who accused her of failing to address multiple issues and serving her family and Thaksin Shinawatra's interests. The motion failed to pass at a vote on 26 March, with Paetongtarn winning 319 votes.
In floating aquatic angiosperms, the leaves have evolved to only have stomata on the top surface to make use of atmospheric carbon dioxide. Gas exchange primarily occurs through the top surface of the leaf due to the position of the stomata, and the stomata are in a permanently open state. Due to their aquatic surroundings, the plants are not at risk of losing water through the stomata and therefore face no risk of dehydration. For carbon fixation, some aquatic angiosperms are able to uptake CO2 from bicarbonate in the water, a trait that does not exist in terrestrial plants. Angiosperms that use HCO3- can keep CO2 levels satisfactory, even in basic environments with low carbon levels. The many possible classifications of aquatic plants are based upon morphology.
Severe Phenotype: symptoms appear soon after birth and include hypoglycemia, hepatomegaly, brain dysfunction (encephalopathy) and often cardiomyopathy Intermediate Phenotype: characterized by hypoketotic hypoglycemia and is triggered by infection or fasting during infancy Mild (Late-Onset) Phenotype: presents as muscle weakness (myopathy) and nerve disease (neuropathy) Long-Term Complications: can include peripheral neuropathy and eye damage (retinopathy) Treatments
Sources: en.wikipedia.org
== Description == The cap of this mushroom grows up to 8–30 cm (3–12 in) wide, sometimes more. Viscid when moist, the cap is convex when young and flattens with age. The colour is generally reddish-brown, sometimes with a paler margin. The stipe grows up to 8–25 cm (3–10 in) tall and 2–7 cm (1–3 in) thick—rather large in comparison to the cap. The stem is usually enlarged at the base when young, becoming more cylindrical in age. It is finely reticulate on the upper portion or sometimes the whole. The flesh of the stem is sometimes dark yellow near the base. The undersurface of the cap consists of thin tubes, the site of spore production; they are 1 to 2 cm (1⁄2 to 3⁄4 in) deep, and whitish in colour when young, but mature to a greenish-yellow. The angular pores, which do not stain when bruised, are small—roughly 2 to 3 pores per millimetre. In youth, the pores are white and appear as if stuffed with cotton (which are actually mycelia); as they age, they change colour to yellow and later to brown. The spore print is olive brown. The flesh of the fruit body is white, thick and firm when young, but becomes somewhat spongy with age. When bruised or cut, it either does not change colour, or turns a very light brown or light red. Mature specimens can weigh about 1 kg (2 lb 3 oz). A huge specimen collected on the Isle of Skye, Scotland, in 1995 weighed 3.2 kg (7 lb 1 oz); its cap was 42 cm (16+1⁄2 in) wide and the stipe was 18 cm (7 in) tall and 14 cm (5+1⁄2 in) wide. A similarly sized specimen found in Poland in 2013 made international news.
%) is also used as aquarium plants fertilizer. The more soluble form of iron, Fe(II), is a micronutrient needed by aquatic plants. By binding to Fe2+ ions DTPA prevents their precipitation as Fe(OH)3, or Fe2O3·nH2O poorly soluble oxy-hydroxides after their oxidation by dissolved oxygen. It increases the solubility of Fe2+ and Fe3+ ions in water, and therefore the bioavailability of iron for aquatic plants. It contributes so to maintain iron under a dissolved form (probably a mix of Fe(II) and Fe(III) DTPA complexes) in the water column. It is unclear to what extent does DTPA really contribute to protect dissolved Fe2+ against air oxidation and if the Fe(III)-DTPA complex cannot also be directly assimilated by aquatic plants simply because of its enhanced solubility. Under natural conditions, that is, in the absence of complexing DTPA, Fe2+ is more easily assimilated by most organisms, because of its 100-fold higher solubility than that of Fe3+. In pulp and paper mills DTPA is also used to remove dissolved ferrous and ferric ions (and other redox-active metal ions, such as Mn or Cu) that otherwise would accelerate the catalytic decomposition of hydrogen peroxide (H2O2 reduction by Fe2+ ions according to the Fenton reaction mechanism). This helps preserving the oxidation capacity of the hydrogen peroxide stock which is used as oxidizing agent to bleach pulp in the chlorine-free process of paper making. Several thousand tons of DTPA are produced annually for this purpose in order to limit the non-negligible losses of H2O2 by this mechanism.
== Labeling == The actual leather content of bonded leather varies depending on the manufacturer and the quality level. There is some debate and controversy over the ethics of using the term "bonded leather" to describe an upholstery product, which is actually a reconstituted leather, specifically in the home furnishings industry. A Leather Research Laboratory commented calling a product "bonded leather" is "deceptive because it does not represent its true nature. It's a vinyl, or a polyurethane laminate or a composite, but it's not leather". In 2011 the European Committee for Standardization published EN 15987:2011 'Leather - Terminology - Key definitions for the leather trade' to stop confusion about bonded leather, according to which the minimum amount of 50% in weight of dry leather is needed to use the term "bonded leather". The US Federal Trade Commission recommends giving a percentage of leather included. The Federal Trade Commission has said that "The guidelines caution against misrepresentations about the leather content in products containing ground, reconstituted, or bonded leather, and state that such products, when they appear to be made of leather, should be accompanied by a disclosure as to the percentage of leather or other fiber content. The guidelines also state that these disclosures should be included in any product advertising that might otherwise mislead consumers as to the composition of the product."
Resistin, also known as adipose tissue-specific secretory factor (ADSF) or C/EBP-epsilon-regulated myeloid-specific secreted cysteine-rich protein (XCP1), is a cysteine-rich peptide hormone that is derived from adipose tissue and, in humans, is encoded by the RETN gene. In primates, pigs, and dogs, resistin is secreted primarily by immune and epithelial cells, whereas in rodents, it is mainly secreted by adipose tissue. The human resistin pre-peptide consists of 108 amino acid residues, while in mice and rats it is 114 amino acids in length; the molecular weight is approximately 12.5 kDa. Resistin is classified as an adipose-derived hormone (similar to a cytokine), and its physiological role has been widely debated, particularly regarding its involvement in obesity and type II diabetes mellitus (T2DM).
Ropinirole acts as a D2, D3, and D4 dopamine receptor agonist with highest affinity for D3, which are mostly found in the limbic areas. It is weakly active at the 5-HT2, and α2 receptors and is said to have virtually no affinity for the 5-HT1, GABA, mAChRs, α1-, and β-adrenoreceptors. It is a potent agonist of the 5-HT2B receptor, but shows biased agonism at this receptor and does not appear to pose a risk of cardiac valvulopathy. The comprehensive receptor interactions of ropinirole have been described. Ropinirole produces marked hypolocomotion at lower doses (1–50 mg/kg i.p.) and causes hyperlocomotion at higher doses (100 mg/kg i.p.) in rodents. The former effect is thought to be mediated by activation of inhibitory presynaptic dopamine autoreceptors and reduced dopamine release, while the latter action is thought to be due to stimulation of postsynaptic dopamine receptors. Activation of postsynaptic dopamine D2 receptors is thought to be involved in the antiparkinsonian effects of dopamine D2 receptor agonists like ropinrole.
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 a synthetic pentapeptide in the growth hormone secretagogue family and acts as an agonist at the ghrelin receptor. It is handled as a laboratory research compound rather than a naturally occurring hormone.