A practical reference on reconstitution: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-02. Anything still debated is marked as such rather than presented as settled.
研究背景集中在特定人群的体成分改变，尤其是与脂肪分布异常相关的内脏脂肪堆积。不同地区对它的监管状态与获批适应症并不一致，部分市场仅限特定诊断人群使用。在一般人群中的长期效应、与其他激素的相互作用以及停药后的维持情况仍属开放问题，现有数据不足以给出普遍结论。
tesamorelin 是一种人工合成的四十四肽，序列与内源性生长激素释放激素（GHRH）的 1-44 片段一致，区别在于 N 端加接了一个反式-3-己烯酰基。该修饰抑制二肽基肽酶 IV 的快速切割，从而延长分子在循环中的存留时间。作为肽类分子，它难以经胃肠道吸收，文献中讨论的均是注射途径。分类上通常把它归为 GHRH 类似物，以区别于生长激素本身。
Regulatory position depends on jurisdiction and on the form in which the material is sold. A branded product holds approval in the United States for a defined indication, and prescribing is confined to that label. Material marketed for laboratory research is not evaluated for human use and carries no such clearance. Independent verification therefore rests on certificates of analysis, third-party testing, and documented chain of custody. The substance also appears on the World Anti-Doping Agency prohibited list within the category covering growth hormone-releasing factors.
Lyophilized material is typically held under refrigeration between two and eight degrees Celsius, shielded from light and ambient moisture. Peptides of this size adsorb to glass and plastic, so working procedures often call for low-binding containers and as few transfers as possible. Absorbed water during weighing shifts the apparent mass of a sample, and controlling room humidity reduces that source of error. Once dissolved, solutions are kept cold and used within the interval printed on the accompanying label or certificate. Degradation accelerates markedly in dilute aqueous form.
| 性质 | 取值 | 备注 |
|---|---|---|
| 分子类型 | 合成四十四肽 | GHRH 类似物 |
| N 端修饰 | 反式-3-己烯酰基 | 延缓酶切 |
| 分子量 | 约 5135 Da | 依序列与修饰 |
| 受体靶点 | 垂体 GHRH 受体 | 经 cAMP 通路 |
| 常见同义名 | GHRH(1-44) 类似物 | 文献通用称法 |
Regulatory approval in the United States came in 2010, when the Food and Drug Administration cleared the peptide for the reduction of excess abdominal fat in adults with HIV infection and associated lipodystrophy. The decision rested mainly on two randomized phase 3 trials that enrolled roughly eight hundred patients and ran for twenty-six weeks. Participants receiving active drug showed substantially greater declines in visceral adipose tissue than those receiving placebo, while total body weight changed comparatively little. A reformulated presentation was later approved, and the product has remained a niche therapy rather than a general weight-loss agent.
Tesamorelin occupies a narrow position among agents that act on the growth hormone axis. Unlike growth hormone itself, which is given as replacement, it stimulates the pituitary to release the hormone in pulses, so the downstream increase in insulin-like growth factor 1 depends on intact somatotroph function. Other peptides in the same family include shorter GHRH fragments and synthetic secretagogues with different stability profiles. Several points remain unresolved, including whether the reduction in visceral fat translates into fewer cardiovascular events, what happens to metabolic markers after long-term use, and how the drug compares with lifestyle or surgical approaches.
Tesamorelin is a synthetic peptide that belongs to the growth hormone-releasing hormone family and contains the same forty-four amino acid sequence as endogenous GHRH, extended at the amino terminus by a trans-3-hexenoyl group. That small fatty acid modification protects the peptide from rapid cleavage by dipeptidyl peptidase-4, the enzyme that shortens the half-life of native GHRH to only a few minutes. Chemically the compound is produced by solid-phase peptide synthesis, purified by chromatography, and supplied as a sterile lyophilized powder for reconstitution.
Lyophilized tesamorelin is generally stored refrigerated at 2 to 8 degrees Celsius, protected from light and moisture. Peptides in this class are often kept frozen at minus 20 degrees Celsius for longer periods. Reconstituted solutions are typically used within a defined window because hydrolysis and oxidation proceed faster in liquid form. Container material and headspace also influence how long a preparation retains its expected profile. Specific stability figures depend on concentration and buffer composition.
Common analytical approaches include reversed-phase high-performance liquid chromatography for purity assessment and mass spectrometry for identity confirmation. Peptide mapping after enzymatic digestion can verify the expected sequence. Immunoassays may be used to measure the compound or its downstream markers, but they can cross-react with related peptides and require careful validation. Impurity profiles typically include truncated sequences, oxidized methionine residues, and residual solvents from synthesis. Each method reports a different property, so no single assay establishes overall quality.
Tesamorelin is a synthetic peptide analog of growth hormone-releasing hormone, built from 44 amino acids. Its sequence follows the natural human GHRH(1-44) backbone, with a trans-3-hexenoyl group attached to the N-terminal tyrosine. This modification blocks recognition by dipeptidyl peptidase IV, the enzyme that rapidly truncates the native hormone in circulation. The result is a molecule with a substantially longer plasma residence time than unmodified GHRH, which makes it practical for clinical and laboratory study.
Receptor-level activity begins when the peptide binds the GHRH receptor, a class B G-protein-coupled receptor found on pituitary somatotroph cells. Occupancy triggers Gs-mediated activation of adenylyl cyclase and a rise in intracellular cyclic AMP, which in turn promotes synthesis and pulsatile release of growth hormone. Because the compound acts upstream of the growth hormone axis rather than supplying hormone directly, its effect depends on intact pituitary function. Binding studies in cell culture and animal models have established this pathway; the detailed kinetics of receptor recycling in humans remain less well characterized.
Physicochemical behavior is dominated by the peptide backbone. The molecule is hydrophilic and carries a net positive charge near neutral pH, owing to several arginine and lysine residues. In solution it adopts a largely unstructured conformation, and aggregation is a known concern for peptide products of this size. Oxidation of methionine and deamidation of asparagine or glutamine residues are the principal chemical degradation routes. These liabilities shape how the material is formulated, handled, and analyzed, and they explain why lyophilized presentations are common in research settings.
Once reconstituted, the peptide is handled as a solution and is less stable than the lyophilized powder. Aqueous solutions are commonly kept cold and used within a defined period. Buffer composition and pH influence degradation rates, with extremes of acidity or alkalinity accelerating hydrolysis. Preservatives may be added in multi-dose formats to limit microbial growth. Freezing and thawing of solutions is generally avoided because it can cause precipitation or loss of activity.
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass and detects chemical modifications. Peptide mapping and amino acid analysis can verify sequence integrity. Water content is measured by Karl Fischer titration, and residual solvents may be checked by gas chromatography. These methods together support batch-to-batch consistency and routine quality control.
== Atomic mass of isotopes == The atomic mass of an isotope (nuclide) is determined mainly by its atomic mass number (i.e. number of nucleons in its nucleus). Small corrections are due to the binding energy of the nucleus (see mass defect), the slight difference in mass between proton and neutron, and the mass of the electrons associated with the atom, the latter because the electron:nucleon ratio differs among isotopes. The mass number is a dimensionless quantity. The atomic mass, on the other hand, is measured using the dalton (symbol Da), which is defined in terms of the mass of the carbon-12 atom. It is also called the unified atomic mass unit (symbol u). The atomic masses of naturally occurring isotopes of an element determine the standard atomic weight of the element. When the element contains N isotopes, the expression below is applied for the average atomic mass
== Adverse effects == Nephrotoxicity: Like cisplatin, nephrotoxicity, harm to the kidneys, is the primary dose-limiting factor. However, the nephrotoxicity of nedaplatin has been shown to be less severe than cisplatin. In rats, nedaplatin primarily affected the renal papilla, with papillary necrosis in severe cases. Neurotoxicity: Nedaplatin is widely reported to be neurotoxic, especially to the nerves of the ear. Causing symptoms like numbness and tingling in mild cases, or sensory ataxia in more severe cases. Nausea and vomiting: The emetogenic effects of nedaplatin are commonly managed with prophylactic antiemetics, such as duplex dexamethasone and ondansetron or triplex dexamethasone, ondansetron and aprepitant. Ototoxicity: Nedaplatin is toxic to the nerve and hair cells in the cochlea. In rats, nedaplatin was severely toxic to the nerve cells at a concentration of 10 μM, with damage to hair cells becoming more severe exceeding 100 μM. Neutropenia, leukopenia, anemia and thrombocytopenia (see "Aqupla アクプラ" in External Links): Nedaplatin is toxic to the hemopoietic cells of the bone marrow, combined with reduced levels of erythropoietin, leads to elevated incidence of bone marrow suppression compared to cisplatin. Incidence of severe grades of leukopenia and neutropenia are reported to be higher than cisplatin in treatment combined with radiotherapy. These haematological adverse effects are common in general.
=== Novo Nordisk Foundation === On March 1, 2021, Thomsen was appointed CEO of the Novo Nordisk Foundation, a philanthropic organization that funds research in health, life sciences, and sustainability.
== Other uses == Recurrent pyogenic cholangitis, a medical condition Red Paraguaya de Comunicación, a TV operator in Paraguay Rei Publicae Constituendae, part of the title of the members of the Second Triumvirate, appearing on Roman coins République populaire de Chine, República popular China, República popular da China, the French, Spanish and Portuguese names for the People's Republic of China RPC, a Panamanian national television network
The Wolf Prize in Chemistry is awarded annually by the Wolf Foundation in Israel. It is one of the six Wolf Prizes established by the Foundation and has been awarded since 1978; the others are in Agriculture, Mathematics, Medicine, Physics, and Arts. The Wolf Prize in Chemistry is considered to be one of the most prestigious international chemistry awards, behind only the Nobel Prize in Chemistry. Becoming a Wolf Prize laureate has been viewed as a potential precursor to receiving the Nobel Prize. As of 2025, 13 awardees have subsequently become Nobel laureates; the most recent of those is Omar M. Yaghi.
Sources: en.wikipedia.org
== Analysis == In simple manual columns, the eluent is collected in constant volumes, known as fractions. The more similar the particles are in size the more likely they are in the same fraction and not detected separately. More advanced columns overcome this problem by constantly monitoring the eluent.
Migraine is a neurological disorder that causes moderate-to-severe headaches. The pain often affects one side of the head, but can affect both. It is generally associated with nausea, light sensitivity and sound sensitivity. Other symptoms may include dizziness, vomiting, and difficulty thinking. In some cases, a migraine attack begins with a period of sensory disturbance known as an aura. Some people experience occasional migraine attacks, while others develop chronic migraine with frequent headaches. Migraine frequency can increase over time. In some cases, frequent use of pain medications can make migraines worse and lead to medication overuse headache. Attacks are more likely to happen when changes occur in a person's daily routine. These triggers can include lack of sleep, disrupted sleep, skipped meals, and hormonal fluctuations. Migraine is believed to result from a combination of genetic, environmental, and neurological factors that affect the activity of nerve cells and chemical signals in the brain. Migraine attacks are theorized to occur when the brain exceeds an individual's sensitivity threshold. Migraine attacks have multiple phases. The initial phase of a migraine attack can start 48 hours before the main headache phase and may cause early warning symptoms. The subsequent pain phase of a migraine attack may be linked to increased activity in the pain pathway of the brain, with heightened blood flow and transmission of pain signals.
Under such circumstances, the emu runs in a chaotic manner and changes directions frequently to try to evade its attacker. While full-grown adults are rarely preyed upon, dingos, raptors, monitor lizards, introduced red foxes, feral and domestic dogs, and feral pigs occasionally feed on emu eggs or kill small chicks. Adult males fiercely defend their chicks from predators, especially dingos and foxes.
=== Availability === Carbetocin has been approved for use under the following three brand names in 23 countries: Duratocin (Argentina, Australia, Bahrain, Canada, China, Hong Kong, Italy, Malaysia, Singapore, New Zealand), Lonactene (Mexico), and Pabal (Austria, Belgium, Switzerland, Germany, Estonia, France, United Kingdom, Hungary, Lithuania, Luxembourg, Finland). Duratocin has also been approved for veterinary use in Poland, Germany, Italy, Belgium, Luxembourg, France and the Netherlands. It is not available in the United States or Japan.
Sources: en.wikipedia.org
== Acquisitions == 2000: Icon acquired UK-based regulatory consultancy, YRCR Ltd.; Central Laboratory in New York; and bioanalytical consultancy, Pacific Research 2002: Icon acquired clinical research provider, BPA. 2003: Icon acquired Medieval, a UK-based Phase I facility, and US consulting firm, Globomax 2004: Icon acquired medical imaging specialist, Beacon Bioscience Inc. 2006: Icon acquired outcomes research and health economics specialist, Ovation Research Group 2007: Icon acquired European staffing group, DOCS International 2008: Icon acquired US phase I provider, Healthcare Discoveries and US bioanalytical lab, Prevalere Life Sciences 2009: Icon acquired Veeda Laboratories, a UK biomarker lab 2010: Icon acquired Timaq Medical Imaging Inc.
=== Distinguished Achievement in Proteomic Sciences Award (since 2004) === 2025 Yu-Ju Chen 2021 Nicolle H. Packer 2020 Karin Rodland 2019 Jennifer Van Eyk 2018 Kathryn K. Lilley 2015 Amanda Paulovich 2012 Carol Robinson 2004 Angelika Görg
=== Structure-activity relationship === Hydrocortisone, or 17-hydroxycorticosterone, is under the class of glucocorticoids, which are steroids synthesized in the adrenal cortex of the kidneys. In order to illustrate its glucocorticoid activity, the A ring of hydrocortisone has a keto group in the 3rd carbon and a double bond between the 4th and 5th carbon. For the C ring of the compound, the 11th carbon has a beta hydroxyl substitution, which is also necessary for the drug to demonstrate glucocorticoid effects.
Sources: en.wikipedia.org
tesamorelin 属 GHRH 类似物，作用于垂体受体以促进内源生长激素释放；生长激素本身是直接补充的外源激素。两者在给药逻辑、作用位点和反馈调控路径上并不相同。
作为多肽，它难以通过胃肠道吸收，通常需要注射给药。口服会因消化酶降解而失去活性，因此文献中讨论的都是注射途径。
公开研究多集中在内脏脂肪、体成分分布以及与生长激素轴相关的代谢指标。长期安全性和在普通人群中的适用性尚缺乏一致结论。
Reconstituted solutions are kept cold and used within the period stated on the label or certificate. Repeated warming and cooling cycles should be avoided because they encourage aggregation and gradual loss of potency.