The short version of 双受体激动 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-23 and is reviewed periodically as new material appears.
Research-grade material circulates through suppliers that differ widely in documentation and testing practice, so a certificate of analysis is a starting point rather than proof of quality. Independent verification typically repeats chromatographic purity and mass confirmation on the received lot, and compares results against a retained reference standard. Regulatory status varies by jurisdiction, and a substance cleared as a medicine is not interchangeable with a research chemical of the same name. Open questions include how closely non-pharmaceutical lots match approved material in impurity profile and in aggregate content.
Solid tirzepatide is handled as a lyophilised, hygroscopic peptide powder that should be kept desiccated, protected from light, and stored frozen, typically at or below minus twenty degrees Celsius for long-term retention. Material left at ambient temperature for extended periods can take up moisture, which promotes aggregation and deamidation. Commercial liquid presentations are kept refrigerated between two and eight degrees Celsius and are not frozen. Reconstituted laboratory solutions are generally held cold and used within a short window because hydrolysis and oxidation continue slowly in solution.
Identity and purity are usually established with reversed-phase high-performance liquid chromatography for the main peak and with mass spectrometry for the observed molecular mass. Peptide mapping after enzymatic digestion confirms the primary sequence, while amino acid analysis provides a quantitative composition check. Size-exclusion chromatography and ion-exchange chromatography are used to look for aggregates and charge variants. Water content, residual solvents, and counter-ion content are measured separately, since a lyophilised powder is often reported on an as-is basis unless a correction is applied.
脂肪酸侧链的存在使该肽与血浆白蛋白结合能力增强，从而延长循环半衰期，支持每周一次给药的用药间隔。白蛋白结合同时改变组织分布特征，减慢肾脏清除速度。该设计思路在多种长效肽类药物中被反复采用，属于既定的药代动力学策略。
该化合物的名称与结构由国际非专利名称体系统一维持，不同文献中出现的同义写法主要在拼写顺序或盐形式描述上不同。研究者通常通过受体结合实验、细胞内环磷酸腺苷积累测定以及动物模型来确认其双激动活性。相当一部分分子层面的细节——例如两条受体通路之间的信号交叉作用——尚处于开放问题状态。
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid, may form a loose cake |
| Solubility class | Soluble in water | Practically insoluble in nonpolar solvents |
| Storage temperature, solid | -20 °C or below | Desiccated and protected from light |
| Storage temperature, liquid | 2-8 °C | Refrigerated, not frozen |
| Typical identity method | LC-MS | Observed mass compared with calculated mass |
Tirzepatide is a synthetic peptide developed as a dual agonist at the glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors. Its structure is built on a GIP-derived backbone with non-natural amino acid substitutions and a fatty diacid side chain that promotes albumin binding and slows clearance. That modification supports once-weekly subcutaneous dosing. Registrational trial programs reported reductions in body weight and glycated hemoglobin alongside the drug's glycemic effects.
Both receptors are class B G protein-coupled receptors that signal largely through Gs-mediated cyclic AMP production. Activation within pancreatic islets increases glucose-dependent insulin secretion and suppresses glucagon release when glucose is elevated. Outside the pancreas, signaling in the central nervous system and gut appears to influence appetite and gastric emptying. The relative contribution of each receptor to observed clinical effects remains under investigation, and the two pathways are not simply additive in practice.
质量控制环节关注外观、含量、纯度、有关物质、水分与微生物限度等项目。检测结果需要有对照品和系统适用性数据支持，单次测定不足以判定批次的稳定性。实验室之间方法转移时，色谱柱品牌与梯度差异常导致保留时间漂移，因此方法验证十分必要。
固体状态的 tirzepatide 通常以冻干粉形式保存，推荐在低温、避光、干燥条件下存放，常见区间为 2 至 8 摄氏度，长期保存可考虑更低温度并避免反复冻融。冻融循环会导致肽链聚集或析出，从而影响后续定量结果。容器密封性与湿度控制同样是稳定性研究中反复强调的因素。
溶解操作一般使用注射用水或适宜的水性缓冲液，必要时加入少量助溶剂以改善溶解速度，但应避免剧烈涡旋振荡，因为剪切力可能促进聚集。配制后的溶液在冷藏条件下的稳定时间通常短于固体形态，具体时限取决于浓度、缓冲体系与容器材质。是否加入防腐成分，则取决于用途是否为多次取样。
Pelvic floor muscles help to support the vulvar structures. The voluntary, pubococcygeus muscle, part of the levator ani muscle partially constricts the vaginal opening. Other muscles of the urogenital triangle support the vulvar area and they include the transverse perineal muscles, the bulbospongiosus, and the ischiocavernosus muscles. The bulbospongiosus muscle decreases the vaginal opening. They play a role in the vaginal contractions of orgasm by causing the vestibular bulbs to contract.
=== Intermediate === This type is a milder form of MSUD in comparison to classic MSUD. Intermediate MSUD has greater levels of residual enzyme activity than classic MSUD. The majority of children with intermediate MSUD are diagnosed between the ages of 5 months and 7 years. Symptoms associated with classic MSUD also appear in intermediate MSUD. Maple syrup odor to the urine and earwax is observed. Patients with intermediate MSUD may be presented with acidosis and developmental delay.
Unsuccessful treatment procedure which can lead to recurrent defect Post-treatment infection Barrier membrane being worn away, caused by e.g. traumatic toothbrushing Vitality of tooth being compromised in furcation-involved teeth Unfavourable gingival adaptation which can be of aesthetic concern Dentine hypersensitivity Requirement for long term professional maintenance
== Veterinary medicine == Tramadol was the most common opioid prescribed by American veterinarians from 2014 to 2019; however, usage has declined in subsequent years due to more recent evidence suggesting that dogs do not metabolise tramadol into O-desmethyltramadol effectively. As metabolisation of tramadol relies on cytochrome P450 enzymes, it is species dependent and even individual genetics can have a profound impact on the efficacy of tramadol. A 2021 meta-analysis of tramadol use in dogs found that although tramadol was more effective than nalbuphine and codeine, it was less effective than methadone, COX inhibitors and multimodal analgesia with poor evidence to support the use of it is an analgesic for dogs. The mean alveolar concentration sparing effect of tramadol is negligible and with a high likelihood of rescue analgesia being required thus tramadol monotherapy is not recommended for the dog. One study looking at tramadol and meloxicam administered preoperatively provided no benefit compared to meloxicam given alone. Another study looking at cimicoxib versus tramadol for long-term post-operative pain following a tibial-plateau-levelling osteotomy found that although the level of analgesia was similar cimicoxib resulted in better mobility and a lower incidence of hock oedema. These studies and other evidence suggest that non-steroidal anti-inflammatory drugs provide superior analgesia to tramadol in dogs. Tramadol is more effective in cats although oral tramadol is poorly tolerated leading to low compliance.
Sources: en.wikipedia.org
The Aston Medal is awarded by the British Mass Spectrometry Society to individuals who have worked in the United Kingdom and have made outstanding contributions to our understanding of the biological, chemical, engineering, mathematical, medical, or physical sciences relating directly to mass spectrometry. The medal is named after one of Britain's founders of mass spectrometry and 1922 Nobel prize winner Francis William Aston. The award is made sporadically, with no more than one medal being awarded each year. Recipients of this honour receive a gold-plated medal with a portrait of Francis Aston as well as an award certificate.
=== World Health Organization === The World Health Organization has declared that finding where SARS-CoV-2 came from is a priority and that it is "essential for understanding how the pandemic started." In May 2020, the World Health Assembly, which governs the World Health Organization (WHO), passed a motion calling for a "comprehensive, independent and impartial" study into the COVID-19 pandemic. A record 137 countries, including China, co-sponsored the motion, giving overwhelming international endorsement to the study. In mid 2020, the World Health Organization (WHO) began negotiations with the government of China on conducting an official study into the origins of COVID-19. In November 2020, the WHO published a two-phase study plan. The purpose of the first phase was to better understand how the virus "might have started circulating in Wuhan", and a second phase involves longer-term studies based on the findings of the first phase. WHO director-general Tedros Adhanom said "We need to know the origin of this virus because it can help us to prevent future outbreaks," adding, "There is nothing to hide. We want to know the origin, and that's it." He also urged countries not to politicise the origin tracing process, saying that would only create barriers to learning the truth. In 2021, the World Health Assembly (on behalf of the WHO) commissioned a study conducted jointly between WHO experts and Chinese scientists. Echoing the assessment of most virologists, the study concluded that the virus most likely had a zoonotic origin in bats, possibly via an intermediate host.
=== Mechanical properties === Crystalline cellulose has a stiffness about 140–220 GPa, comparable with that of Kevlar and better than that of glass fiber, both of which are used commercially to reinforce plastics. Films made from nanocellulose have high strength (over 200 MPa), high stiffness (around 20 GPa) but lack of high strain (12%). Its strength/weight ratio is 8 times that of stainless steel. Fibers made from nanocellulose have high strength (up to 1.57 GPa) and stiffness (up to 86 GPa).
Sources: en.wikipedia.org
Traffic is heavy worldwide, with the biggest producer being Afghanistan. According to a U.N. sponsored survey, in 2004, Afghanistan accounted for production of 87 percent of the world's diamorphine. Afghan opium kills around 100,000 people annually. In 2003 The Independent reported:
where Vatom = Vcell/n and n is the number of atoms per unit cell of volume Vcell. The unit cell of silicon has a cubic packing arrangement of 8 atoms, and the unit cell volume may be measured by determining a single unit cell parameter, the length a of one of the sides of the cube. The CODATA value of a for silicon is 5.431020511(89)×10−10 m. In practice, X-ray crystallography measurements are carried out on a distance known as d220(Si), which is the distance between the planes denoted by the Miller indices {220}, and is equal to a/√8. The isotope proportional composition of the sample used must be measured and taken into account. Silicon occurs in three stable isotopes (28Si, 29Si, 30Si), and the natural variation in their proportions is greater than other uncertainties in the measurements. The atomic weight Ar for the sample crystal can be calculated, as the standard atomic weights of the three nuclides are known with great accuracy. This, together with the measured density ρ of the sample, allows the molar volume Vm to be determined:
By the early 1980s, the USSR had built up a military arsenal and army surpassing that of the United States. Soon after the Soviet invasion of Afghanistan, President Carter began massively building up the United States military. This buildup was accelerated by the Reagan administration, which increased the military spending from 5.3 percent of GNP in 1981 to 6.5 percent in 1986, the largest peacetime defense buildup in United States history. The American-Soviet tensions present during 1983 was defined by some as the start of "Cold War II". While in retrospective this phase of the Cold War was generally defined as a "war of words", the Soviet's "peace offensive" was largely rejected by the West. Tensions continued to intensify as Reagan revived the B-1 Lancer program, which had been canceled by the Carter administration, produced LGM-118 Peacekeeper missiles, installed US cruise missiles in Europe, and announced the experimental Strategic Defense Initiative, dubbed "Star Wars" by the media, a defense program to shoot down missiles in mid-flight. The Soviets deployed RSD-10 Pioneer ballistic missiles targeting Western Europe, and NATO decided, under the impetus of the Carter presidency, to deploy MGM-31 Pershing and cruise missiles in Europe, primarily West Germany. This deployment placed missiles just 10 minutes' striking distance from Moscow.
Sources: en.wikipedia.org
It is normally kept frozen, desiccated, and away from light, with brief warming to room temperature before opening to limit condensation. Repeated freeze-thaw cycles are avoided because they stress the peptide. Once in solution, the material is held cold and used promptly.
Mass spectrometry gives the observed molecular mass, which is compared with the calculated value for the expected sequence. Reversed-phase chromatography shows retention behaviour and main peak purity. Peptide mapping adds sequence-level confirmation when the question requires it.
Typical entries include appearance, chromatographic purity as area percent, observed mass, water or residual solvent content, and the analytical methods used. The document reflects the lot tested and the laboratory that performed the work. It does not by itself establish that the delivered vial matches the tested lot.
它属于合成修饰肽，同时激动 GIP 与 GLP-1 两种肠促胰素受体。这类分子通常被称为双重肠促胰素受体激动剂，与选择性 GLP-1 激动剂在靶点范围上不同。