If you have been reading about incretin receptor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-04-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
Tirzepatide is a synthetic peptide that activates both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. This dual agonist profile distinguishes it from earlier incretin-based compounds that act on a single receptor. The molecule was engineered from the native GIP sequence and carries several non-natural residues that slow enzymatic breakdown. Researchers designed it to combine the insulinotropic effects of GIP signaling with the appetite and gastric-emptying effects associated with GLP-1 activation.
Development of tirzepatide took place under a research program that sought to test whether simultaneous engagement of two incretin receptors would produce greater metabolic effects than single-receptor agonism. Clinical trials were organized into the SURPASS series for type 2 diabetes and the SURMOUNT series for obesity and weight management. Regulatory clearance for type 2 diabetes came in 2022 in the United States, followed by approval for chronic weight management in 2023. The trial programs reported reductions in glycated hemoglobin and body weight relative to comparators, though long-term cardiovascular and durability data continue to accumulate.
The peptide backbone contains 39 amino acids and includes alpha-aminoisobutyric acid residues, which are not among the standard proteinogenic set. A C20 fatty diacid moiety is attached through a linker, allowing the compound to bind serum albumin and extend its circulation time. This albumin binding is the main reason the molecule supports once-weekly administration rather than more frequent dosing. The measured molecular mass is approximately 4,813 daltons, placing it firmly in the peptide rather than small-molecule class.
| Property | Value | Notes |
|---|---|---|
| 储存温度 | 2 至 8 摄氏度 | 固体粉末，避光密封 |
| 外观 | 白色至类白色冻干粉 | 溶解后为澄清至微乳光 |
| 溶解性 | 易溶于水性缓冲液 | 避免剧烈振荡 |
| 常规纯度方法 | 反相高效液相色谱 | 紫外或质谱检测 |
| 定量方法 | 液相色谱串联质谱 | 配合固相萃取前处理 |
Tirzepatide activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor, making it a dual agonist rather than a selective agent. Engagement of the GLP-1 receptor is linked to glucose-dependent insulin release, slower gastric emptying, and reduced appetite signalling. The relative contribution of the GIP arm remains an active research question; proposed roles include improved insulin sensitivity and altered adipose tissue handling. Receptor occupancy studies suggest the molecule interacts with both targets at circulating concentrations achieved during therapy.
Development began in the 2010s, when researchers modified a GIP-based scaffold to add GLP-1 activity and then attached the fatty diacid to lengthen its half-life. Clinical evaluation proceeded through large phase 3 programmes in type 2 diabetes and in obesity, and regulators in the United States cleared the compound for type 2 diabetes in 2022 and for chronic weight management in 2023. Several cardiovascular and metabolic outcome studies are still reporting, so the picture of long-term benefit and risk is incomplete. Approvals in other regions followed on different timelines.
Tirzepatide is a synthetic peptide of 39 amino acids that carries a C20 fatty diacid side chain attached through a linker. Its molecular formula is C225H348N48O68, and its molecular weight is about 4813 daltons. The compound belongs to the incretin mimetic class and is administered by subcutaneous injection. The fatty acid chain promotes binding to serum albumin, which slows renal clearance and extends the circulation time of the molecule. It was identified during screening of sequences derived from glucose-dependent insulinotropic polypeptide.
Identity and purity are established with reversed-phase high-performance liquid chromatography, often paired with mass spectrometry for confirmation of the expected mass. Peptide mapping after enzymatic digestion verifies the primary sequence and detects substitutions. Size-exclusion chromatography quantifies aggregates and fragments, which are the impurities most often tracked for peptides of this size. Residual solvents, counterions, and water content fall under separate tests described in pharmacopeial chapters. Circular dichroism or nuclear magnetic resonance may be used in research settings to probe secondary structure, though such methods are less common in routine release testing.
Peptide active ingredients of this type are typically supplied as lyophilized powder because the dry form resists hydrolysis during transport. The material is hygroscopic, so vials are usually equilibrated to room temperature before opening to avoid condensation on the solid. Repeated freeze-thaw cycles can promote aggregation and are generally avoided by aliquoting stock into single-use portions. Personnel handling the powder work in controlled environments to limit inhalation of fine particles. Written procedures usually specify these steps rather than leaving them to individual judgment.
Long-term storage of the solid generally relies on temperatures at or below minus twenty degrees Celsius, while short-term working stocks may be held refrigerated. Light exposure is limited because photodegradation can alter side chains over extended periods. Solutions prepared for analysis are less stable than the dry powder and are typically used within the same working day. Buffer choice matters, since some aqueous conditions favor deamidation or oxidation at specific residues. Stability data are usually generated under defined accelerated conditions and then extrapolated with stated assumptions.
Clinical research programs have evaluated tirzepatide in adults with type 2 diabetes and in adults with obesity or excess weight. Trials generally reported reductions in glycated hemoglobin and body weight across treatment periods of several months. Since these studies enrolled defined populations under controlled conditions, the findings describe group averages rather than individual outcomes. Open questions include the durability of effects after treatment stops, variation among subgroups, and the long-term consequences of sustained dual receptor stimulation. Published trial summaries should be consulted for exact measurements rather than secondary accounts.
Tirzepatide is a synthetic peptide built from 39 amino acid residues. Its backbone derives from the native glucose-dependent insulinotropic polypeptide sequence, altered at several positions to resist enzymatic cleavage. A fatty diacid group attached through a linker extends plasma residence time by promoting reversible binding to serum albumin. The molecule carries a net negative charge near physiological pH and has a reported molecular weight close to 4813 daltons. These features separate it from shorter incretin analogs and account for its prolonged dosing interval.
The foreskin is the double-layered fold of tissue at the distal end of the human penis that covers the glans and the urinary meatus. Different amounts of skin can be removed during circumcision. The practice is differentiated from other surgeries for the treatment of phimosis or treatment-resistant infection by the complete removal of the preputial orifice.
Chlorarachniophytes are a rare group of organisms that also contain chloroplasts derived from green algae, though their story is more complicated than that of the euglenophytes. The ancestor of chlorarachniophytes is thought to have been a eukaryote with a red algal derived chloroplast. It is then thought to have lost its first red algal chloroplast, and later engulfed a green alga, giving it its second, green algal derived chloroplast. Chlorarachniophyte chloroplasts are bounded by four membranes, except near the cell membrane, where the chloroplast membranes fuse into a double membrane. Their thylakoids are arranged in loose stacks of three. Chlorarachniophytes have a form of polysaccharide called chrysolaminarin, which they store in the cytoplasm, often collected around the chloroplast pyrenoid, which bulges into the cytoplasm. Chlorarachniophyte chloroplasts are notable because the green alga they are derived from has not been completely broken down—its nucleus still persists as a nucleomorph found between the second and third chloroplast membranes—the periplasmic space, which corresponds to the green alga's cytoplasm.
=== Democratic constitution, NATO and European Union memberships === There were several post-Solidarity governments between the 1989 election and the 1993 election, after which the "post-communist" left-wing parties took over. In 1993, the formerly Soviet Northern Group of Forces, a vestige of past domination, left Poland. In 1995, Aleksander Kwaśniewski of the Social Democratic Party was elected president and remained in that capacity for the next ten years (two terms). In 1997, the new Constitution of Poland was finalized and approved in a referendum; it replaced the Small Constitution of 1992, an amended version of the communist constitution. Poland joined NATO in 1999. Elements of the Polish Armed Forces have since participated in the Iraq War and the War in Afghanistan (2001–2021). Poland joined the European Union as part of its enlargement in 2004. However, Poland has not adopted the euro as its currency and legal tender, but instead uses the Polish złoty. In April 2010, Polish president Lech Kaczynski and dozens of the country's top political and military leaders died in the Smolensk air disaster. After the election of the far-right conservative Law and Justice party in 2015, the Polish government repeatedly clashed with EU institutions on the issue of judicial reform and was accused by the European Commission and the European Parliament of undermining "European Values" and eroding democratic standards.
Sources: en.wikipedia.org
== Research == Some of Patton's earliest research in collaboration with D. V. Josephson revealed that a change in methionine in milk was responsible for the off flavor produced when milk is exposed to light. In other of his early work Patton discovered that malonic dialdehyde is a product of lipid oxidation and the basic reactant in the thiobarbituric acid and Kreis tests for lipid oxidation. One of the first to use gas chromatography, mass spectrometry and thin layer chromatography in flavor research, Patton proved, using these techniques, that methyl sulfide is a key component in the flavor of milk, methods his student Allen Day, who went on to become vice-president for research at IFF, put to good use. At Penn State, "in the 1960s and 1970s, Patton would lead a departmental redirection into lipid research with important insights on mammary gland milk fat synthesis,” but he attributed the turn in his research from the characterization of milk lipids to milk synthesis and secretions to Robert McCarthy. Patton's research in this area is summarized in Biomedical Aspects of Lactation. While lipid research continued to be a focus of Patton's investigations on the various expeditions he participated on with Andrew Benson, (for example, the importance of triglyceride in the salmon's heart function; the chemical characterization of unique lipids in marine animals), an investigation that demonstrated the high food value of the red tide organism (the phytoplankton bloom), remains under explored.
== Early life and education == Namandjé Bumpus was born in Philadelphia and raised in western Massachusetts. She became interested in chemistry at a young age, even writing to the American Chemical Society while still in elementary school to ask about the kind of careers chemists can have. She earned a B.A. in Biology from Occidental College, in Los Angeles, California, in 2003. At Occidental, she was introduced to research experiences in ecology, then she ventured into pharmacology through Charles Ross Summer Research Fellowship at the University of Michigan, during which she was mentored by Dr. Richard R. Neubig. She enjoyed the experience so much that she decided to return to the University of Michigan after graduating from Occidental College in order to pursue a PhD in pharmacology. She earned her Ph.D. in pharmacology from the University of Michigan Medical School in 2007. Her thesis research, and much of her later work, examined how drugs are processed by cytochrome P450 enzymes, (CYPs) a family of heme-containing monooxygenases, that often help make drugs more soluble, aiding with drug clearance. Bumpus performed her thesis research in the laboratory of Dr. Paul F. Hollenberg, investigating how a naturally occurring mutation in CYP2B6 affects its ability to be inactivated by compounds known the inactivate the wild-type CYP2B6. She also looked into how naturally occurring variants could impact how patients cleared the antidepressant Bupropion, and the antiviral Efavirenz.
As such, the HPA axis starts to become suppressed and atrophy. If this occurs the patient should be tapered off prednisone slowly to give the adrenal gland enough time to regain its function and endogenous production of steroids.
== Plot summary == Anathem is set on the fictional planet of Arbre. Thousands of years before the events in the novel, the planet's intellectuals entered concents (monastic communities) to protect their activities from the collapse of society. The avout (intellectuals separated from Sæcular society) are banned from possessing or operating most advanced technology and are supervised by the Inquisition, which answers to the outside world. The avout are normally allowed to communicate with people outside the walls of the concent only once every year, decade, century, or millennium, depending on the particular vows they have taken. The narrator and protagonist, Fraa Erasmas, is an avout at the Concent of Saunt Edhar. His teacher, Fraa Orolo, discovers that an alien spacecraft is orbiting Arbre – a fact that the world government (Sæcular Power) attempts to cover up. Erasmas becomes aware of Orolo's discovery after Orolo is banished (in a rite called Anathem) from the concent for using a video camera (a forbidden technology) to observe the ship. The presence of the alien ship soon becomes an open secret among many of the avout at Saunt Edhar. The alien ship eventually declares its presence by shining a laser upon several Millenarian Maths (the bastions of those avout who have taken a thousand-year vow of isolation). Shortly after that, the Sæcular Power summons many avout from Saunt Edhar, including Erasmas and a Millenarian named Fraa Jad. The avout are told to travel to the concent of Saunt Tredegarh to attend a Convox (a joint conference of the avout and the Sæcular Power).
Sources: en.wikipedia.org
"Brazil does not grant unilateral exemptions of visitor visas, without reciprocity, to other countries. [...] In attention to the interests of Brazilian citizens, the Brazilian government will be ready to continue negotiating, with the four aforementioned countries, visa waiver agreements on reciprocal bases." — Ministry of Foreign Affairs (Itamaraty). The return of visa charges was received with criticism by some entities linked to the tourism and hospitality sector. For Feliciano Sá Guimarães, director of the Brazilian Center for International Relations, the measure is an obstacle to the development of national tourism and "a vain retrograde nationalist defense". Although the National Confederation of Tourism (Cntur) "did not view it favorably", Wilson Luis Pinto, executive president of the entity, stated that he believed the government took a calculated measure and that the country would not cease to be an option for foreign travelers. "Whoever decided they want to come here will come." Luis Pinto also expressed support for the proposal: "I, as a Brazilian, do not think it is fair to spend months in line and pay a fee to obtain a visa, while an American can buy a ticket and come to Brazil". The government assessed that the resumption of visas would have a low impact on tourism and, according to the Polícia Federal, although in 2019 there were some peaks in the entry of people from North America into Brazil after the visa exemption, this number did not show much increase compared to the period before the measure.
=== Phase 1 === AZD-4041 – orexin OX1 receptor antagonist – opioid-related disorders BI-1356225 – ghrelin O-acyltransferase (GOAT) inhibitor – opioid-related disorders Cebranopadol (GRT-6005; PRK-101; TRN-228) – μ-opioid receptor agonist, nociceptin receptor agonist – substance-related disorders CSX-1004 – monoclonal antibody against fentanyl – opioid-related disorders Dimethyltryptamine/harmine (DMT/harmine; RE-01) – combination of dimethyltryptamine (DMT) (serotonin 5-HT2A receptor agonist and serotonergic psychedelic) and harmine (monoamine oxidase inhibitor (MAOI) and other actions) – cocaine-related disorders DPI-125 (MCP-201) – μ-opioid receptor agonist, δ-opioid receptor agonist, κ-opioid receptor agonist – opioid-related disorders Ibuprofen/ketotifen (SJP-005) – combination of ibuprofen (cyclooxygenase (COX) inhibitor/NSAID) and ketotifen (histamine H1 receptor antagonist, other actions) – opioid-related disorders Icalcaprant (ABBV-1354; CVL-354) – κ-opioid receptor antagonist – opioid-related disorders KNX-100 (SOC-1) – oxytocin-like drug / indirect oxytocin receptor modulator – opioid-related disorders, substance-related disorders Mavoglurant (AFQ-056; STP-7) – metabotropic glutamate mGlu5 receptor antagonist – cocaine-related disorders MEB-1170 – μ-opioid receptor biased agonist – opioid-related disorders Mebufotenin (5-MeO-DMT) – non-selective serotonin receptor agonist, serotonin 5-HT1A and 5-HT2A receptor agonist, and serotonergic psychedelic – substance use disorders MST-01 – undefined mechanism of action – smoking withdrawal Nalmefene (AV-104; TH-104) – μ-opioid receptor antagonist, κ-opioid receptor weak partial agonist – opioid-related disorders Naltrexone implantable pellets (BICX-102, BICX-104) – opioid receptor antagonist – alcoholism, opioid-related disorders, substance-related disorders Nezavist (DCUK-OEt) – peripherally selective GABAA receptor positive allosteric modulator (etomidate site) – alcoholism Noribogaine (DMX-1001) – various actions – alcoholism NRS-033 (nalmefene prodrug) – μ-opioid receptor antagonist, κ-opioid receptor weak partial agonist – opioid-related disorders OMS-527 (OMS-182399; OMS527) – phosphodiesterase PDE7 inhibitor – cocaine-related disorders Psilocybin (MLS-101/MLS101) – non-selective serotonin receptor agonist, serotonin 5-HT2A receptor agonist, serotonergic psychedelic – opioid-related disorders Smoking cessation therapeutics - Astraea Therapeutics – nicotinic acetylcholine receptor antagonists – smoking withdrawal SXC-2023 – cystine/glutamate transporter (SLC7A11) – cocaine-related disorders Tezampanel (LY-293558; NGX-424; PRN-001-01) – ionotropic glutamate AMPA and kainate receptor antagonist – opioid-related disorders Zabaglurant (Heptares 25; HTL-0014242; HTL14242; TMP-301) – metabotropic glutamate mGlu5 receptor negative allosteric modulator – cocaine-related disorders, substance-related disorders
17α-Hydroxyprogesterone (17α-OHP), also known as 17-OH progesterone (17-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many other endogenous steroids, including androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as neurosteroids.
== Implications == These properties of the genetic code make it more fault-tolerant for point mutations. For example, in theory, fourfold degenerate codons can tolerate any point mutation at the third position, although codon usage bias restricts this in practice in many organisms; twofold degenerate codons can withstand silence mutation rather than Missense or Nonsense point mutations at the third position. Since transition mutations (purine to purine or pyrimidine to pyrimidine mutations) are more likely than transversion (purine to pyrimidine or vice versa) mutations, the equivalence of purines or that of pyrimidines at twofold degenerate sites adds a further fault-tolerance.
South Africa In South Africa, the five-door-only 323 proved an immediate success. The 1.3 was gradually replaced by the larger 1.4 from July 1978, while a Special and a CS model were added at the low and high ends of the lineup respectively, complementing the existing De Luxe models. Well-equipped versions of the 1978 facelift model were sold as the "323 GLC" in South Africa. A 1600-cc model was also available in South Africa – however this model did not have a Mazda engine, unlike the rest of the range. To satisfy that country's local content regulations, a locally built Mitsubishi Saturn 1.6-litre unit was used. This produces 77 PS (57 kW) and was the most powerful engine to be installed in the FA-series Familia/323. It arrived in early 1979, but period testers felt that the less-revvy 1.6 provided very little that the 1.4 did not offer, and could not be considered to be worth the price. Fuel consumption dropped, while top speed of 148 km/h (92 mph) was only marginally higher than the 145 km/h (90 mph) of the smaller version. Sigma also fielded a rotary-engined 323 in the South African national rally championship.
Sources: en.wikipedia.org
建议在低温、避光、干燥环境中密封保存，常见条件为 2 至 8 摄氏度，长期存放可置于更低温度。应避免反复冻融，并尽量减少容器开启次数。
溶解后的稳定时间通常短于固体形态，受浓度、缓冲液和容器材质影响。冷藏条件下一般只能维持较短时间，具体期限应通过实际稳定性实验确认。
反相高效液相色谱用于纯度与含量测定，液相色谱串联质谱用于生物基质中的定量，体积排阻色谱用于检测聚集体。多种方法结合才能较完整地表征样品。
It binds and activates both the GIP and GLP-1 receptors, making it a dual incretin receptor agonist. Single-receptor GLP-1 agonists act on one target only. The dual profile is the defining pharmacological feature of the molecule.