This is a working overview of IGF-1, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-08-26. Anything still debated is marked as such rather than presented as settled.
纯度与身份确认依赖色谱与质谱的组合。反相高效液相色谱在 214 nm 紫外检测下分离主峰与相关杂质，给出纯度百分比与保留时间；电喷雾或基质辅助激光解吸电离质谱提供分子量，用于确认 N 端修饰是否完整。序列层面可通过肽图或氨基酸分析验证。含量测定常用紫外吸收法或氮元素分析，不同方法之间需要做交叉校验。
冻干粉末一般在 -20°C 或更低温度、干燥避光条件下保存，可维持较长时间的稳定。复溶后稳定性明显下降，溶液中的肽链易发生水解、氧化与聚集，通常需冷藏并在短期内用完。反复冻融会加速聚集与降解，建议分装后单次使用。缓冲体系的 pH 与离子强度同样影响聚集速率，需要按具体实验条件验证。
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.
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.
| 性质 | 取值 | 备注 |
|---|---|---|
| 外观 | 白色至类白色冻干粉 | 常见形态 |
| 溶解性 | 易溶于水与水性缓冲液 | 多肽类通性 |
| 典型储存温度 | -20°C 或更低 | 干燥避光 |
| 常用纯度方法 | 反相高效液相色谱 | 214 nm 紫外检测 |
| 常用分子量确认 | 质谱 | 电喷雾或激光解吸 |
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.
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.
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.
FOP is an autosomal dominant disorder. Thus, a child of an affected heterozygous parent and an unaffected parent has a 50% probability of being affected. Two affected individuals can produce unaffected children. Two unaffected individuals can produce an affected offspring as a result of the mutation of the gene. The homozygous dominant form is more severe than the heterozygous form. The protein that causes ossification is normally deactivated by an inhibitory protein after a fetus's bones are formed in the womb, but in patients with FOP, the protein keeps working. Aberrant bone formation in patients with FOP occurs when injured connective tissue or muscle cells at the sites of injury or growth incorrectly express an enzyme for bone repair during apoptosis (self-regulated cell death), resulting in lymphocytes containing excess bone morphogenetic protein 4 (BMP4) provided during the immune system response. The bone that results occurs independently of the normal skeleton, forming its own discrete skeletal elements. These elements, however, can fuse with normal skeletal bone. The diaphragm, tongue, and extra-ocular muscles are spared in this process, as well as cardiac and smooth muscle. Since the incorrect enzyme remains unresolved within the immune response, the body continues providing the incorrect BMP4-containing lymphocytes. BMP4 is a product that contributes to the development of the skeleton in the normal embryo. The ACVR1 gene encodes a bone morphogenic protein (BMP) receptor; this gene is mutated in FOP.
In 1957, Boyd Orr served as president of the Second International Humanist Congress, and contributed to the 1968 volume The Humanist Outlook alongside many other prominent humanists. In 1960 Boyd Orr was elected the first president of the World Academy of Art and Science, which was set up by eminent scientists of the day concerned about the potential misuse of scientific discoveries, most especially nuclear weapons. Along with Albert Einstein, Orr was one of the sponsors of the Peoples' World Convention (PWC), also known as Peoples' World Constituent Assembly (PWCA), which took place in 1950–51 at Palais Electoral, Geneva, Switzerland. He was also one of the signatories of the agreement to convene a convention for drafting a world constitution. As a result, for the first time in human history, a World Constituent Assembly convened to draft and adopt the Constitution for the Federation of Earth. Boyd Orr was a member of Bertrand Russell's Who Killed Kennedy? Committee which challenged the official version of the assassination of John F. Kennedy.
=== 2025 === In January 2025, before taking office, Trump stated he would not exclude using economic or military force against Greenland and that the United States needed the territory for national security. On 6 January 2025, he threatened to "tariff Denmark at a very high level" if it did not agree to Trump's plan. On 11 January, Donald Trump Jr. went on a private visit to Greenland. Local media reported that his entourage passed out MAGA hats to locals and attempted to speak to residents on a speakerphone. Pipaluk Lynge, a Greenlandic member of parliament, called the visit "staged". Berlingske reported that an American military person asked the Joint Arctic Command to provide information about Greenlandic infrastructure. In the following months, Republican congressman Buddy Carter introduced a bill in the United States Congress to advance efforts to annex Greenland and rename it Red, White, and Blueland and US vice president JD Vance visited, without invitation, the Pituffik Space Base, where he gave a speech about how Denmark had failed Greenlanders. Vance's visit was condemned by Greenlandic and Danish politicians, and described as a provocation. In connection with the visit, commander Susannah Meyers, the highest-ranking US officer in Greenland, said the Trump administration's threats against the Kingdom of Denmark "are not reflective of Pituffik Space Base". In response, Meyers was fired by Trump.
Sources: en.wikipedia.org
== Further reading == Marshall, Eliot (1983-06-10). "The murky world of toxicity testing" (PDF). Science. 220 (4602): 1130–1132. Bibcode:1983Sci...220.1130M. doi:10.1126/science.6857237. PMID 6857237. Lloyd v. Industrial Bio-Test Laboratories, Inc, 454 F. Supp. 807 (S.D.N.Y. 1978-07-25). Rosner, David; Markowitz, Gerald (2023). ""Ashamed to Put My Name to It": Monsanto, Industrial Bio-Test Laboratories, and the Use of Fraudulent Science, 1969–1985". American Journal of Public Health: e1–e6. United States of America, Plaintiff-appellee, v. Joseph C. Calandra, Moreno Keplinger, Paul L. Wright, and James B. Plank, Defendants-appellants, 706 F.2d 225 (7th Cir. 1983-05-03). United States of America, Plaintiff-appellee, v. Moreno L. Keplinger, Paul L. Wright, and James B. Plank, Defendants-appellants, 776 F.2d 678 (7th Cir. 1985-10-29).
Outbreaks of disease Food-born illness Bioterrorism Natural disasters APHL plays a critical role in crisis response to these public health emergencies through the Laboratory Response Network (LRN). The LRN was formed in 1999 in a cooperative effort between APHL, the CDC and FBI to rapidly detect, and respond to public health emergencies. The Department of Defense has joined in the effort to support biological response activities. In addition to their leadership during times of crisis, APHL has a strong focus on preparing public health laboratories on how to respond to emergencies when they happen through training and capacity-building, as well as creating model frameworks that labs around the country can use in order to have procedures in place to handle a crisis when it happens.
Food and Drug Administration (FDA) also assigned it to a Schedule I classification, and the International Olympic Committee banned it as a potential doping agent. Anecdotal reports concerning ibogaine's effects appeared in the early 1960s. Its anti-addictive properties were discovered accidentally by Howard Lotsof in 1962, at the age of 19, when he and five friends—all heroin addicts—noted subjective reduction of their craving and withdrawal symptoms while taking it. Further anecdotal observation convinced Lotsof of its potential usefulness in treating substance addictions. He contracted with a Belgian company to produce ibogaine in tablet form with the name Endabuse for clinical trials in the Netherlands, and was awarded a United States patent for the product in 1985. The first objective, placebo-controlled evidence of ibogaine's ability to attenuate opioid withdrawal in rats, was published by Dzoljic et al. in 1988. Diminution of morphine self-administration was reported in preclinical studies by Glick et al. in 1991. Cappendijk et al. demonstrated reduction in cocaine self-administration in rats in 1993, and Rezvani reported reduced alcohol dependence in three strains of "alcohol-preferring" rats in 1995. As the use of ibogaine spread, its administration varied widely; some groups administered it systematically using well-developed methods and medical personnel, while others employed haphazard and possibly dangerous methodology. Lotsof and his colleagues, committed to the traditional administration of ibogaine, developed treatment regimens themselves.
=== Freeze drying (lyophilized) === Donkey milk can be freeze-dried to preserve the biological quality of the milk, and so preserve its nutritional, functional, and cosmetic properties. This is possible because in freeze drying the milk is frozen and brought under vacuum at low temperatures. During this process, the water is removed by sublimation. The result is approximately ten percent of dry matter that is called lyophilized (or freeze-dried) donkey milk. This powder is easy to reconstitute. The lyophilized product has to be packaged without any oxygen. It has a shelf life of two years. Normally it is produced from pasteurized donkey milk so it is ready to use. Analysis of freeze-dried donkey's milk has demonstrated that the natural colour, flavours, nutrients, and bioactive substances of fresh donkey milk are retained. Spray-drying is another way to dry products, in which the milk is heated and vitamins and other important bioactive substances may get lost. In contrast, Freeze-drying does not require chemical preservatives and can be either consumed directly or re-hydrated easily. However, this method for is costly, and is practiced only by a few companies. This product is easy to find in Italy, where it was for the first time put on the market.
Sources: en.wikipedia.org
多肽在反相柱上按疏水性差异分离，能有效区分主峰、缺失序列片段与氧化产物。配合紫外检测可获得可量化的纯度百分比，是肽类分析的常规手段。
一般建议密封、避光、干燥，并在 -20°C 或更低温度下存放。温度波动和湿气是主要风险，长期存放应避免反复开启容器。
没有统一答案，取决于缓冲液、浓度、pH 与储存温度。多数做法是冷藏并在数天至数周内用完，具体期限需要通过稳定性实验确认。
The amino acid sequence matches human growth hormone-releasing hormone, but the amino terminus carries a trans-3-hexenoyl group instead of a free amine. That single structural change chiefly affects enzymatic stability rather than receptor selectivity.