This is a working overview of Insulin-like growth factor 1, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-30 and is reviewed periodically as new material appears.
特沙莫瑞林的检测通常依赖反相高效液相色谱和质谱联用。反相色谱可分离肽主峰与缺失序列、氧化产物等杂质,质谱则提供精确质量以确认身份。对于复杂基质中的定量,常采用液相色谱-串联质谱,并配合固相萃取或蛋白沉淀。生物样品中的肽易降解,因此采集和处理条件会影响结果。
稳定性研究通常考察温度、光照、湿度和 pH 对肽链的影响。冻干粉在低温避光条件下较为稳定,复溶后则需控制保存时间并避免反复冻融。肽类可能发生氧化、脱酰胺、水解和聚集,这些变化会改变色谱纯度。强制降解实验用于识别主要降解途径并验证分析方法的专属性。
特沙莫瑞林是一种合成肽,其序列与人生长激素释放激素的 44 个氨基酸形式相关。它在 N 端带有反式-3-己烯酰基修饰,这一改动可减缓二肽基肽酶 IV 的降解。该化合物属于生长激素释放激素受体激动剂,可刺激垂体释放生长激素。研究文献通常将其归入合成肽类药物,而非小分子化合物。
监管记录显示,特沙莫瑞林于 2010 年在美国首次获得批准,用于人类免疫缺陷病毒感染相关的脂肪营养不良患者。批准依据来自降低内脏脂肪的临床试验,而非体重或瘦体重的普遍改善。后续出现了不同制剂版本,但其核心适应症保持一致。关于长期心血管结局和死亡率影响,现有证据仍不充分。
在临床研究之外,特沙莫瑞林常被讨论为生长激素分泌促进剂,但这一说法需要限定。它并不等同于生长激素本身,也不属于普通减重药物。部分研究关注其减少腹部脂肪和改善脂质谱的潜力,另一些研究则关注胰岛素抵抗和 IGF-1 升高等信号。这些效应的临床意义仍在评估中,尚未形成统一结论。
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色冻干粉 | 可能具吸湿性 |
| 溶解性 | 溶于水和水性缓冲液 | 典型肽类行为 |
| 冻干粉储存 | -20°C 或 2-8°C,避光 | 长期稳定性较好 |
| 复溶后储存 | 2-8°C,短期 | 避免反复冻融 |
| 常用分析 | RP-HPLC 与 LC-MS | 纯度与身份确认 |
Stimulated growth hormone release leads to hepatic production of insulin-like growth factor 1, a key mediator of many growth hormone effects. In clinical studies, tesamorelin increased IGF-1 levels in a dose-dependent manner, although the response varies among individuals. The drug's effect on visceral fat is thought to involve growth hormone-mediated lipolysis and altered adipocyte metabolism. Muscle mass and lean body mass have also been assessed as secondary outcomes, but changes are generally smaller and less consistent than fat reductions.
Pharmacodynamic studies show that tesamorelin reduces visceral adipose tissue more than subcutaneous adipose tissue in the studied population. This selectivity may relate to differences in blood flow and hormone sensitivity between fat depots. Effects on glucose metabolism and insulin sensitivity have been investigated, with some trials reporting modest changes and others showing stability. The precise relationship between growth hormone exposure, IGF-1 levels, and visceral fat loss remains an active area of analysis.
A Phase 3 program led to regulatory approval in the United States in 2010 for reduction of excess visceral abdominal fat in adults with HIV and lipodystrophy. Subsequent studies examined effects on liver fat, muscle area, and metabolic markers, with mixed findings for some endpoints. Long-term cardiovascular outcomes and effects on mortality remain uncertain because most trials were relatively short and focused on imaging-based fat measurements. Use in populations without HIV has been studied experimentally but is not part of the approved indication.
Tesamorelin is a synthetic analog of growth hormone-releasing hormone, a peptide hormone produced by the hypothalamus. The molecule retains the 44-amino-acid sequence of human GHRH and carries a trans-3-hexenoyl modification at its N-terminus. This modification increases resistance to enzymatic degradation and extends the peptide's functional stability relative to native GHRH. The compound is supplied as a lyophilized powder for reconstitution and subcutaneous administration in clinical settings. Its development code was TH9507, and it belongs to the GHRH analog class. It is not a growth hormone product; instead, it acts upstream to stimulate endogenous growth hormone release.
Clinical interest in tesamorelin arose from the need to address visceral adiposity in people living with HIV. Antiretroviral therapy improved survival but was associated in some patients with central fat accumulation, altered lipid profiles, and metabolic complications. This condition, often called HIV-associated lipodystrophy, involves excess visceral adipose tissue that is difficult to manage through diet and exercise alone. Investigators evaluated tesamorelin because GHRH analogs can stimulate growth hormone secretion and influence fat distribution without direct liposuction or invasive procedures.
Whether the drug improves hard clinical outcomes is not settled. No completed trial has shown a reduction in heart attacks or strokes among treated patients, although a dedicated cardiovascular outcomes study has been discussed in the literature. Investigators have also examined hepatic fat in people with HIV and fatty liver disease, cognitive measures in small cohorts, and changes in bone density. Regulatory labeling emphasizes monitoring of insulin-like growth factor 1 because supraphysiologic levels raise questions about tissue growth, and the clinical significance of that signal remains an open question rather than a demonstrated harm.
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.
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.
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.
Biocon Limited is an Indian biopharmaceutical company based in Bengaluru, with U.S. headquarters in Bridgewater, New Jersey. Founded by Kiran Mazumdar-Shaw in 1978 as a partner to the Irish brewing enzyme manufacturer Biocon Biochemicals Ltd., the company manufactures generic active pharmaceutical ingredients (APIs) that are sold in approximately 120 countries, including the United States and Europe. It also manufactures novel biologics, and branded drugs such as biosimilar insulins and antibodies for the Indian domestic market. Biocon's biosimilar products are also sold in both bulk and formulation forms in several emerging markets. Biocon's formulations for the Indian market include metabolics, oncology, immunotherapy, and nephrology products. Some of Biocon's key brands in India include INSUGEN (rh-insulin), BASALOG (Glargine), BIOMAb EGFR (Nimotuzumab), BLISTO (Glimepiride + Metformin), CANMAb (Trastuzumab), Evertor (Everolimus), TACROGRAF (Tacrolimus), ALZUMAb (Itolizumab) and KRABEVA (Bevacizumab). Syngene International Limited (Syngene) is a publicly listed subsidiary of Biocon, operating in the contract research and development organization.
Cammack R, Jackson RH, Cornish-Bowden A, Cole JA (1982). "Electron-spin-resonance studies of the NADH-dependent nitrite reductase from Escherichia coli K12". Biochem. J. 207 (2): 333–9. doi:10.1042/bj2070333. PMC 1153865. PMID 6297458. Lazzarini RA; Atkinson DE (1961). "A triphosphopyridine nucleotide-specific nitrite reductase from Escherichia coli". J. Biol. Chem. 236 (12): 3330–3335. doi:10.1016/S0021-9258(18)94019-6. PMID 14463130. Nicholas DJ, Medina A, Jones OT (1960). "A nitrite reductase from Neurospora crassa". Biochim. Biophys. Acta. 37 (3): 468–76. doi:10.1016/0006-3002(60)90503-5. PMID 14426899. Taniguchi H, Mitsui H, Nakamura K, Egami F. "Ann. Acad. Sci. Fenn. Ser. A II 60 (1955) 200". {{cite journal}}: Cite journal requires |journal= (help) Colandene JD, Garrett RH (1996). "Functional dissection and site-directed mutagenesis of the structural gene for NAD(P)H-nitrite reductase in Neurospora crassa". J. Biol. Chem. 271 (39): 24096–104. doi:10.1074/jbc.271.39.24096. PMID 8798648.
== Structure == Serous membranes have two layers. The parietal layers of the membranes line the walls of the body cavity (pariet- refers to a cavity wall). The visceral layer of the membrane covers the organs (the viscera). Between the parietal and visceral layers is a very thin, fluid-filled serous space, or cavity.
Sources: en.wikipedia.org
=== Hematopoietic stem cell transplant === Bronchiolitis obliterans affects up to 5.5% of people who have received HSCT. One of the biggest risk factors after HSCT is the development of GVHD with a 14% risk. Other risk factors post transplant including tobacco use, age of donor, age of recipient, lower baseline FEV1/FVC ratio, non-caucasian race, peripheral and lower circulating IgG levels. Studies have, however, shown mixed results regarding these other risk factors. There has been an association shown between the increased use of peripheral stem cells and the risk of developing bronchiolitis obliterans. Also, research has shown an increased risk for developing the disease within the first year of transplant if the person is infected with respiratory syncytial virus or parainfluenza virus within the first 100 days post transplant.
Gene expression is the process by which the information contained within a gene is used to produce a functional gene product, such as a protein or a functional RNA molecule. This process involves multiple steps, including the transcription of the gene's sequence into RNA. For protein-coding genes, this RNA is further translated into a chain of amino acids that folds into a protein, while for non-coding genes, the resulting RNA itself serves a functional role in the cell. Gene expression enables cells to utilize the genetic information in genes to carry out a wide range of biological functions. While expression levels can be regulated in response to cellular needs and environmental changes, some genes are expressed continuously with little variation.
Nucleolus Nuclear speckle Cajal body Paraspeckle Synaptonemal complex Other nuclear structures including heterochromatin form by mechanisms similar to phase separation, so can also be classified as biomolecular condensates. RNAs with triplet expansion that produce neurodegenerative disorders can also independently form RNA foci in vitro or in mammalian nuclei. This phenomenon is further reconsituted in bacteria E. coli, by expressing engineered CAG repeats, providing strong evidence that these RNA repeats phase separate without the need of additional proteins.
Bussolari of the MIT Lincoln Laboratory; the aerodynamicist was Mark Drela, with his XFOIL; in 1986, the team moves to Hanscom Field; the pilot Lois McCallin; after three to four hours of heavy exercise, the body's glucose is depleted; the first test aircraft had no ailerons, to save weight, resulting in a crash; a Hellenic Air Force C-130 arrives at Heraklion International Airport on 26 March 1988; three pilots train on Crete, eating around 7000 calories per day; the flight occurs on Saturday 23 April 1988, flying at around 18 knots; a gust of wind snapped the tail boom and wing on the beach. A US production, narrated by Andrew Sachs, produced by Mark Davis, made by WGBH. Shown on Nova on 22 November 1988 14 October Junk Mail, about direct marketing, increased by the affordability of computers, with Erik Larson.
Sources: en.wikipedia.org
=== Horseshoe clip === A horseshoe clip is the U-shaped spring steel fitting that holds the side-plate of the joining (or "master") link formerly essential to complete the loop of a roller chain. The clip method is losing popularity as more and more chains are manufactured as endless loops not intended for maintenance. Modern motorcycles are often fitted with an endless chain but in the increasingly rare circumstances of the chain wearing out and needing to be replaced, a length of chain and a joining link (with horseshoe clip) will be provided as a spare. Changes in motorcycle suspension are tending to make this use less prevalent. Common on older motorcycles and older bicycles (e.g. those with hub gears) this clip method cannot be used on bicycles fitted with derailleur gears, as the clip will tend to catch on the gear-changers. In many cases, an endless chain cannot be replaced easily since it is linked into the frame of the machine (this is the case on the traditional bicycle, amongst other places). However, in some cases, a joining link with horseshoe clip cannot be used or is not preferred in the application either. In this case, a "soft link" is used, placed with a chain riveter and relying solely on friction. With modern materials and tools and skilled application this is a permanent repair having almost the same strength and life of the unbroken chain.
Phosphate – used for the production of nucleic acids, phospholipids (an important component of the cell membrane) and ATP (Adenosine triphosphate which the cell uses for transferring energy for metabolism). Potassium – important for the uptake and utilization of phosphate Biotin – involved in the synthesis of proteins, fatty acids and nucleic acids. Pantothenic acid – involved in the metabolism of sugars and lipids. A deficiency of this vitamin could lead into increase hydrogen sulfide production with off-aromas in the resulting wine. Nicotinic acid – involved in the synthesis of Nicotinamide adenine dinucleotide (NAD+), a co-enzyme that is important in maintaining the redox balance of the cell as well as in the process of ethanol fermentation itself. Inositol – involved with the secondary messenger molecules that facilitate cell division. Trace amounts of calcium, chlorine, copper, iron, manganese and zinc for healthy cell function.
As demanded by the Allied Commission, the German police escorted Polish actors but they ignored the attackers. In Bischofsburg (Biskupiec), a pogrom against Poles was organised, which prompted the creation of a special commission to find the perpetrators. The Allensteiner Zeitung newspaper called on its readers to remain calm and to cease pogroms against Poles and pointed out that they could lead to postponing the plebiscite, which would go against German interests. Italian forces were sent to Lötzen (Giżycko), according to Minakowski, to protect the Poles after a pogrom had occurred on 17 April. In May, several attacks on Poles were reported in Osterode (Ostróda) and included attacks on coworkers of the Masurian Committee.
saturation hybridization An in vitro nucleic acid hybridization reaction in which one polynucleotide component (either DNA or RNA) is supplied in great excess relative to the other, causing all complementary sequences in the other polynucleotide to pair with the excess sequences and form hybrid duplex molecules.
Covalent modification: Functionalization with carboxyl groups can reduce cellular and pulmonary toxicity by suppressing NLRP3 inflammasome activation and downregulating pro-inflammatory cytokines (e.g., IL-1β, TGF-β1, PDGF-AA). PEGylation, the covalent attachment of polyethylene glycol (PEG), reduces cellular uptake, protein adsorption, oxidative stress, and immune activation, reducing immune recognition and systemic inflammation.
Sources: en.wikipedia.org
反相高效液相色谱用于分离和纯度评估,质谱用于分子量确认。肽图谱或串联质谱可进一步验证序列。具体方法需根据样品基质和监管要求选择。
高温、强光、潮湿和反复冻融都会加速肽降解。冻干粉通常建议低温避光保存。复溶后的溶液稳定性较短,应依据验证数据确定保存条件。
氧化、脱酰胺和截短肽可能影响色谱纯度和生物活性读数。不同批次之间这些杂质的相对比例可能不同。是否具有临床意义取决于杂质水平、给药途径和暴露量,尚无统一阈值。
特沙莫瑞林是国际非专利名称,指一种经过 N 端修饰的生长激素释放激素类似物。它被归类为合成肽,序列与 GHRH(1-44) 密切相关。该名称不指代任何特定品牌或剂型。