tesamorelin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
作用位置在垂体前叶。tesamorelin 与 GHRH 受体结合后激活腺苷酸环化酶,升高细胞内 cAMP,再经蛋白激酶 A 通路促进生长激素的合成与释放。由于它作用于内源调控节点,生长激素仍以脉冲方式分泌,而不是被持续抬升到固定水平。生长激素随后在肝脏等组织诱导胰岛素样生长因子 1 产生,构成完整的生长激素轴响应。
Published work tends to frame tesamorelin as a tool for studying the GHRH axis and as a compound with measurable effects on body composition. Reports often describe visceral adipose tissue as an endpoint, assessed by imaging rather than by inference. Analytical sections commonly describe liquid chromatography with tandem mass spectrometry to confirm identity and purity, because immunoassays may cross-react with related fragments. Where results diverge between studies, differences in assay choice, sampling timing, and population are frequent explanations offered. Whether effects persist after treatment stops remains an open question.
Tesamorelin binds the growth hormone–releasing hormone receptor on pituitary somatotroph cells. The receptor signals through the Gs protein, raising intracellular cAMP and activating protein kinase A. That cascade triggers release of stored growth hormone in pulses rather than a steady stream. Because the drug acts at the receptor that normally controls this process, its effect depends on the body's own signaling architecture rather than on a synthetic pathway. The resulting hormone profile reflects the timing of each pulse, not only its size.
Measured responses usually involve growth hormone and insulin-like growth factor 1, known as IGF-1. Growth hormone rises in bursts and is difficult to sample reliably, while IGF-1 shifts more slowly and can be assessed from a single blood draw. Studies therefore treat IGF-1 as the more practical pharmacodynamic marker. Both are indirect, showing that the receptor was engaged rather than that the peptide reached a particular concentration. Direct exposure measurement requires an assay aimed at the molecule itself.
| 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 |
Signaling begins at the GHRH receptor, a class B G protein-coupled receptor displayed on somatotroph cells of the anterior pituitary. Receptor occupancy activates Gs proteins, which raise adenylyl cyclase activity and intracellular cyclic AMP, in turn driving protein kinase A dependent pathways. The downstream output is synthesis and pulsatile secretion of growth hormone into the bloodstream. Hepatic tissue and peripheral sites respond by increasing insulin-like growth factor 1 production. Somatostatin and IGF-1 itself supply negative feedback that caps the size and duration of each secretory burst.
Metabolic interest in this compound centers on fat distribution rather than on hormone levels alone. Imaging trials in adults with excess abdominal fat report reductions in visceral adipose tissue, while subcutaneous depots change comparatively little. Growth hormone and IGF-1 are presumed to carry the effect, but the separate contribution of each is not firmly established. Whether these changes persist after treatment stops, and whether they alter longer-term health outcomes, remain open questions that published work does not answer consistently.
Tesamorelin is a synthetic peptide of forty-four amino acids whose sequence reproduces human growth hormone-releasing hormone. Its distinguishing feature sits at the amino terminus, where a trans-3-hexenoyl group replaces the free amine. That acylation slows cleavage by dipeptidyl peptidase IV, an enzyme that otherwise removes the first two residues and inactivates the natural hormone quickly. The modified peptide therefore persists longer in circulation while keeping the same receptor target. It is handled as a lyophilized solid and dissolved shortly before use.
The peptide is supplied as a lyophilized powder in single-use vials and is normally kept refrigerated between two and eight degrees Celsius, protected from light. Once dissolved, the solution is handled carefully because peptide bonds and the acyl modification can degrade under warm or alkaline conditions. Vials are inspected for cracks, and the powder is checked for color and uniformity before handling. Temperature excursions during shipping are a frequent reason for quality questions.
Identity and purity are assessed with reversed-phase high-performance liquid chromatography, which separates the peptide from truncated or oxidized forms. Mass spectrometry confirms the expected molecular weight, and peptide mapping after enzymatic digestion verifies the amino acid sequence. Water content is measured because residual moisture affects stability, and tests for aggregates or particulates are standard for injectable peptides. Circular dichroism can indicate whether the molecule has adopted an unexpected secondary structure in solution.
Tesamorelin is a synthetic peptide of 44 amino acids that reproduces the sequence of human growth hormone-releasing hormone (GHRH) and carries a trans-3-hexenoyl group on its N-terminal tyrosine. That small fatty-acid modification blocks cleavage by dipeptidyl peptidase-4, the enzyme that rapidly degrades native GHRH in plasma. The result is a molecule with a longer circulating half-life than the natural hormone while retaining the same receptor target. It is supplied as a lyophilized powder for reconstitution and belongs to the broader class of GHRH analogs studied for effects on pituitary growth hormone secretion.
Development work on the compound, originally designated TH9507, focused on conditions in which reduced growth hormone signaling is thought to contribute to altered body composition. The United States Food and Drug Administration approved it in 2010 for the treatment of excess visceral abdominal fat in adults with human immunodeficiency virus infection and lipodystrophy. Later research examined other populations, including adults with mild cognitive impairment, where a large trial did not meet its primary endpoints. This mixed record illustrates how a single mechanism can produce clear effects in one setting and inconclusive results in another.
Several related peptides act on the same receptor, including sermorelin, a shorter GHRH fragment, and modified analogs such as CJC-1295 and modified GRF(1-29) that are common in research settings rather than approved products. Tesamorelin differs from growth hormone itself in that it acts upstream, prompting the pituitary to release the hormone through physiological signaling rather than supplying it directly. Terminology in the literature distinguishes GHRH analogs, growth hormone secretagogues, and recombinant growth hormone, although popular discussion often blurs these categories together. Precise naming matters when comparing study results.
Binding of tesamorelin to the growth hormone-releasing hormone receptor on anterior pituitary somatotrophs activates a Gs protein pathway, raises cyclic AMP, and triggers release of stored growth hormone into the bloodstream. Because the analogue resists dipeptidyl peptidase-4, its plasma residence time exceeds that of native GHRH, producing a larger and more sustained secretory signal. The released growth hormone then acts on the liver and peripheral tissues to raise insulin-like growth factor 1, which feeds back on the hypothalamus and pituitary. This axis explains both the intended effects on fat distribution and the biological markers used to track them.
Studies of the compound rely on imaging and laboratory endpoints rather than on symptoms alone. Visceral adipose tissue is usually quantified by computed tomography or magnetic resonance imaging at the level of the abdomen, with waist circumference serving as a cheaper but less specific proxy. Blood work tracks insulin-like growth factor 1, fasting glucose, glycated hemoglobin, and lipid fractions. In the pivotal trials the imaging endpoint fell by roughly fifteen to twenty percent over six months, subcutaneous fat changed little, and the visceral fat returned toward baseline after treatment stopped, a pattern that shapes how clinicians discuss durability.
=== Chemical === Americium metal readily reacts with oxygen and dissolves in aqueous acids. The most stable oxidation state for americium is +3. The chemistry of americium(III) has many similarities to the chemistry of lanthanide(III) compounds. For example, trivalent americium forms insoluble fluoride, oxalate, iodate, hydroxide, phosphate and other salts. Compounds of americium in oxidation states +2, +4, +5, +6 and +7 have also been studied. This is the widest range that has been observed with actinide elements. The color of americium compounds in aqueous solution is as follows: Am3+ (yellow-reddish), Am4+ (yellow-reddish), AmVO+2; (yellow), AmVIO2+2 (brown) and AmVIIO5−6 (dark green). The absorption spectra have sharp peaks, due to f-f transitions' in the visible and near-infrared regions. Typically, Am(III) has absorption maxima at ca. 504 and 811 nm, Am(V) at ca. 514 and 715 nm, and Am(VI) at ca. 666 and 992 nm. Americium compounds with oxidation state +4 and higher are strong oxidizing agents, comparable in strength to the permanganate ion (MnO−4) in acidic solutions. Whereas the Am4+ ions are generally unstable in solutions and readily convert to Am3+, compounds such as americium dioxide (AmO2) and americium(IV) fluoride (AmF4) are stable in the solid state. The pentavalent oxidation state of americium was first observed in 1951. In acidic aqueous solution the AmO+2 ion is unstable with respect to disproportionation. The reaction
For example, controlled-release oxycodone (OxyContin) or morphine (MS-Contin) are intended to, via novel delivery mechanisms, permit pain relief for up to twelve hours with an active ingredient which only provides relief for 3 to 6 hours. However, the inherent variability amongst different people with respect to drug metabolism makes this task challenging.
will be different for geometries other than the center-cracked infinite plate, as discussed in the article on the stress intensity factor. Consequently, it is necessary to introduce a dimensionless correction factor,
=== Exercise === In 2017, exercise was the only fibromyalgia treatment given a strong recommendation by the European Alliance of Associations for Rheumatology (EULAR). There is strong evidence indicating that exercise improves fitness, sleep and quality of life and may reduce pain and fatigue for people with fibromyalgia. The rate of adverse events reported in studies of exercise is low, with the most common being muscle pain, and no serious adverse events reported. There are several hypothesized biological mechanisms for exercise benefits in FM. Exercise may improve pain modulation through serotonergic pathways. It may reduce pain by altering the hypothalamic-pituitary-adrenal axis and reducing cortisol levels. It also has anti-inflammatory effects that may improve fibromyalgia symptoms. Aerobic exercise can improve muscle metabolism and pain through mitochondrial pathways. Despite its benefits, exercise is a challenge for patients with fibromyalgia, due to the chronic fatigue and pain they experience. They may have negative experiences with being given non-personalized exercise programs by healthcare providers who they feel do not understand the impact of the condition. Adherence is higher when the exercise program is recommended by doctors or supervised by nurses. Sufferers perceive exercise as more effortful than healthy adults. Depression and higher pain intensity serve as barriers to physical activity. A recommended approach to a graded exercise program begins with small, frequent exercise periods and builds up from there.
is called the rate of shear deformation or shear velocity, and is the derivative of the fluid speed in the direction parallel to the normal vector of the plates (see illustrations to the right). If the velocity does not vary linearly with
Sources: en.wikipedia.org
Schiller (1969), lawyer, co-founder of Boies Schiller Flexner LLP Eric Eisner (1970), lawyer, former president of The Geffen Company and founder of the Young Eisner Scholars program William Barr (1971), attorney general of the United States Arthur Engoron (1971), judge presiding over the New York civil investigation of The Trump Organization Arthur Helton (1971), lawyer, refugee advocate Gerard E. Lynch (1972), judge of the United States District Court for the Southern District of New York Gary Stephen Katzmann (1973), judge on the United States Court of International Trade Robert Katzmann (1973), judge of the United States Court of Appeals for the Second Circuit Eric Holder (1973), United States attorney general under Barack Obama, deputy attorney general under Bill Clinton, United States Attorney for the District of Columbia, judge of the Superior Court of the District of Columbia Jonathan Cuneo (1974), lawyer, founding partner of Cuneo Gilbert & LaDuca, LLP Abbe Lowell (1974), partner at Chadbourne & Parke, chief minority counsel during the Impeachment of Bill Clinton Jeffrey L. Kessler (1975), co-chairman of Winston & Strawn; former global litigation chair at Dewey & LeBoeuf Douglas Letter (1975), general counsel to the United States House of Representatives since 2018 J. Richard Cohen (1976), former president of the Southern Poverty Law Center Joseph A. Greenaway Jr.
== References == 11. Website publication of Silver Book: The Silver Book and the NPU Format for Clinical Laboratory Science Reports Regarding Properties, Units, and Symbols . Published Online: 2017-04-25; Published in Print: 2017-04-25
This distorts the shape of the red blood cell, resulting in the characteristic "sickle" shape, and reduces cell flexibility. This rigid, distorted red blood cell can accumulate in blood vessels creating a blockage. The blockage prevents blood flow to tissues and can lead to tissue death which causes great pain to the individual.
== Advantages == There are many advantages to the use of microneedles, the most prominent being the improved comfort of patients. Needle phobia can affect both adults and children, and sometimes can lead to fainting. The benefit of microneedle arrays is that they reduce anxiety that patients have when confronted with a hypodermic needle. In addition to improving psychological and emotional comfort, microneedles have been shown to be substantially less painful than conventional injections. Some studies recorded children's views on blood sampling with microneedles and found patients were more willing when prompted with a less painful procedure than traditional sampling with needles. Microneedles are beneficial to physicians as well, since they produce less hazardous waste than needles and are generally easier to use. Microneedles are also less expensive than needles as they require less material and the material used is cheaper than the materials in hypodermic needles. Microneedles present a new opportunity for home and community-based healthcare. One of the biggest drawbacks of traditional needles is the hazardous waste that they produce, making disposal a serious concern for doctors and hospitals. For patients who require regular administration of medication at home, disposal can become an environmental concern is needles are placed in the trash.
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By 2014, around 20 companies, particularly from emerging markets, were developing biosimilar versions of trastuzumab after Roche/Genentech's patents expired in 2014 in Europe, and in 2019 in the United States. In January 2015, BIOCAD announced the first trastuzumab biosimilar approved by the Ministry of Health of the Russian Federation. Iran also approved its own version of the monoclonal antibody in January 2016, as AryoTrust, and announced its readiness to export the drug to other countries in the Middle-East and Central Asia when trade sanctions were lifted. In 2016, the investigational biosimilar MYL-1401O showed comparable efficacy and safety to the Herceptin branded trastuzumab. Trastuzumab-dkst (Ogivri, Mylan GmbH) was approved in the United States in December 2017, to "treat people with breast cancer or gastric or gastroesophageal junction adenocarcinoma whose tumors overexpress the HER-2 gene." Ogivri was authorized for medical use in the European Union in December 2018. In November 2017, the European Commission authorized Ontruzant, a biosimilar from Samsung Bioepis Co., Ltd, for the treatment of early breast cancer, metastatic breast cancer and metastatic gastric cancer. Ontruzant is the first trastuzumab biosimilar to receive regulatory approval in the European Union. Herzuma was authorized for medical use in the European Union in February 2018. Herzuma, a trastuzumab biosimilar, was approved in the United States in December 2018.
=== Increased synthesis of ATF4 === In homeostasis, eIF2 combines with guanosine triphosphate (GTP) to activate the mRNA which will start transcription and simultaneously lead to the hydrolysis of GTP so that the process can start again. However during an essential amino acid shortage, P-eIF2α is phosphorylated and binds tightly to eIF2B preventing GDP from turning back to GTP leading to fewer mRNAs being activated and fewer proteins being synthesized. This response causes translation to be increased for some mRNAs, including ATF4, which regulates the transcription of other genes.
John Henderson Knox FRS (1927 – 15 October 2018) was a Professor of Physical Chemistry at the University of Edinburgh and is considered a distinguished contributor to the fields of reaction kinetics and chromatography.
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。
It acts on the growth hormone–releasing hormone receptor, a Gs-coupled receptor found on pituitary somatotroph cells. Activation raises cAMP and prompts pulsatile hormone release.