If you have been reading about Incretin 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.
Updated 2025-08-25. Numbers and descriptions here follow the published literature rather than marketing material.
The GIP receptor is expressed in pancreatic islets, adipose tissue, and the central nervous system, while GLP-1 receptors are found in pancreatic islets, the gastrointestinal tract, and the brain. Activation of both receptors can enhance glucose-dependent insulin secretion and reduce glucagon release. The relative contribution of each receptor to the overall pharmacological effect remains an area of ongoing investigation. Preclinical studies suggest that GIP receptor agonism may modulate appetite and energy balance, but the precise mechanisms in humans are not fully established.
In clinical research, tirzepatide has been studied in randomized controlled trials for glycemic control and body weight reduction. These trials typically measure changes in hemoglobin A1c and body weight over periods of several months. The drug is administered by subcutaneous injection, and its pharmacokinetic profile supports once-weekly dosing. Post-marketing surveillance continues to evaluate long-term outcomes and rare adverse events.
定量分析的主流方法是反相高效液相色谱联用紫外或质谱检测，利用肽在疏水固定相上的保留行为确定纯度与含量。对于生物基质中的浓度测定，常采用液相色谱串联质谱，并配合固相萃取或蛋白沉淀进行样品前处理。免疫分析法也可使用，但可能受到结构相关肽的交叉反应干扰。
纯度评估通常综合反相色谱、体积排阻色谱与质谱三方面信息：前者反映疏水性杂质，后者反映聚集体，质谱则确认分子量与主要降解产物。有关降解途径的完整图谱——例如脱酰胺、氧化与水解各占多大比例——在不同储存条件下仍有差异，属于需要逐案验证的问题。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Dual GIP/GLP-1 receptor agonist |
| Amino acid count | 39 | Contains non-natural residues |
| Modification | C20 fatty diacid | Attached via linker; promotes albumin binding |
| Half-life | Approximately 5 days | Supports once-weekly dosing |
| Primary route | Subcutaneous injection | Not for intravenous use |
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.
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 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.
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.
Levobunolol (trade names AKBeta, Betagan, Vistagan, among others) is a non-selective beta blocker. It is used topically in the form of eye drops to manage ocular hypertension (high pressure in the eye) and open-angle glaucoma.
=== October === 1 October – Prime Minister Rishi Sunak announces £20m of levelling up funding to help regenerate seven Scottish towns that are described as having been overlooked. 2 October – ScotRail begins a six months trial during which peak time train fares are scrapped. 3 October – Aberdeen City Council says that reinforced autoclaved aerated concrete (RAAC) is likely to have been used in hundreds of properties in the city. 4 October – Police Scotland pays £60,000 compensation to four traffic officers told to shave off their beards before the force implemented its delayed proposals for a clean shaven policy. 5 October – Labour's Michael Shanks wins the Rutherglen and Hamilton West by-election. 6 October – Police Scotland scraps plans to recruit an extra 200 officers in January 2024 as it attempts to save costs following a projected overspend of £19m. 7 October – The Met Office issues an amber weather alert for heavy rain in Scotland, while roads and train services are disrupted by flooding. Ten people are airlifted to safety after heavy rain causes landslides on two roads in Argyll. 9 October – Bernard Cowan, a grandfather who grew up in the Glasgow area, is confirmed as one of the people killed during a series of attacks launched by Hamas against Israel on 7 October. Humza Yousaf, the First Minister of Scotland, condemns the attacks and expresses concern for his in-laws, who are "trapped" in Gaza after travelling there to visit relatives. The Scottish Medicines Consortium (SMC) approves the weight loss drug semaglutide for use by NHS Scotland.
=== Aircraft === C-4, the US Army designation of the Ford Trimotor AEG C.IV, a German World War I reconnaissance aircraft AGO C.IV, a 1917 German reconnaissance aircraft C-4 Academe, the military version of Gulfstream I twin turboprop business aircraft C-4 Argonaut, a Canadair aircraft derived from the Douglas DC-4 Cierva C.4, a 1922 Spanish experimental autogyro DFW C.IV, a 1916 German reconnaissance aircraft Flight Design C4, a four-seat light aircraft Fokker C.IV, a 1923 Dutch two-seat reconnaissance aircraft Rumpler C.IV, a 1917 German single-engine, two-seater reconnaissance biplane
Sources: en.wikipedia.org
Salvinorin A is a trans-neoclerodane diterpenoid with the chemical formula C23H28O8. Unlike other known opioid-receptor ligands, salvinorin A is not an alkaloid, as it does not contain a nitrogen atom.
== Medical uses == People with Pompe disease have an enzyme deficiency that leads to the accumulation of a complex sugar, called glycogen, in skeletal and heart muscles, which causes muscle weakness and premature death from respiratory or heart failure. Avalglucosidase alfa is indicated for the treatment of people aged one year and older with late-onset Pompe disease (lysosomal acid alpha-glucosidase [GAA] deficiency).
The military base was now ostensibly renamed for Roland L. Bragg, a previously obscure soldier who served in World War II. In a meeting before the Ukraine Defense Contact Group at NATO headquarters, he opposed NATO membership for Ukraine and said that returning Ukraine's borders prior to the annexation of Crimea by Russia was "unrealistic". The Department of Defense invited Jack Posobiec, an alt-right political activist to accompany Hegseth, according to The Washington Post. Hegseth moderated his comments the following day, stating that it would be possible for Ukraine to join NATO given Trump's discretion. In February 2025, Hegseth ordered officials within the Department of Defense to reduce funding on most initiatives and began a purge from within the department, firing three top judge advocate generals and Lisa Franchetti, the chief of naval operations. Hegseth stated that "we want lawyers who give sound constitutional advice" rather than "roadblocks to anything". In March, he ordered US Cyber Command to halt offensive operations against Russia, in an apparent effort to encourage Russian president Vladimir Putin to negotiate an end to the Russo-Ukrainian War.
=== Pain Free Arthritis Exercises === Together with physiotherapists Kobi Schwartz and Danny Kelman, Dr. Mendes developed a system of painless 'reverse action' and 'gravity dependent' exercises to preserve Hip joint mobility. The system has been tested with rewarding results for more than twenty years. The term 'praying exercises' was chosen due to the similarity to movements during rituals in a variety of religions. Later was modified to 'Pain Free Exercises. The exercises move the joint in maximal range with painless motions, keeping low joint pressure, and lubricate the articular cartilage to maintain its viability by alternating light pressure.
Sources: en.wikipedia.org
=== United Kingdom === The legal status of powdered alcohol in United Kingdom is uncertain, although parliament saw no dangers from the sale of powdered alcohol, aside from the loss of tax revenue. In a January 2015 answer to a parliamentary question, Lord Bates wrote "The Government is aware of powdered alcohol from media reports and the banning of the product in five states of the United States of America. The Government is aware of powdered alcohol being marketed and made available in the coming years to buy in England and Wales."
===== MeSH D08.811.399.475 – intramolecular oxidoreductases (EC 5.3) ===== MeSH D08.811.399.475.200 – aldose-ketose isomerases MeSH D08.811.399.475.200.174 – autocrine motility factor MeSH D08.811.399.475.200.350 – glucose-6-phosphate isomerase MeSH D08.811.399.475.200.550 – mannose-6-phosphate isomerase MeSH D08.811.399.475.200.662 – neuroleukin MeSH D08.811.399.475.200.775 – triose-phosphate isomerase MeSH D08.811.399.475.400 – carbon-carbon double bond isomerases MeSH D08.811.399.475.400.700 – steroid isomerases MeSH D08.811.399.475.800 – sulfur-sulfur bond isomerases MeSH D08.811.399.475.800.550 – protein disulfide-isomerase MeSH D08.811.399.475.900 – thromboxane-a synthase
== Deliverables == The EFI's primary deliverable is development and dissemination of an integrated sequence/structure strategy for functional assignment. The EFI now offers access to two high-throughput docking tools, a web tool for comparing protein sequences within entire protein families, and a web tool for composing a genome context inventory based on a protein sequence similarity network. Additionally, as the strategy is developed, data and clones generated by the EFI are made freely available via several online resources.
Up to this point, Counterparts and Test for Echo were two of Rush's most guitar-driven albums. The latter album also includes elements of jazz and swing-style drumming by Peart, which he had learned from drum coach Freddie Gruber during the interim between Counterparts and Test for Echo. "Stick It Out" from Counterparts reached the summit of the US Mainstream Rock Tracks Chart, with the album peaking at No. 2 in the US and No. 6 in Canada. Test for Echo reached the Top 5 in both countries, with the title track again topping the US Mainstream Rock Tracks Chart. In October 1996, in support of Test For Echo, the band embarked on a North American tour, the band's first without an opening act and dubbed "An Evening with Rush". The tour was broken into two segments, spanning October through December 1996 and May through July 1997. After the conclusion of the Test for Echo tour in 1997, the band entered a five-year hiatus primarily due to personal tragedies in Peart's life. Peart's daughter Selena died in a car crash in August 1997, and his wife Jacqueline died of cancer in June 1998. Peart went on hiatus to mourn and reflect. During that time, he travelled extensively throughout North America on his BMW motorcycle, covering 88,000 km (55,000 mi). In his book Ghost Rider: Travels on the Healing Road, Peart writes of how he had told his bandmates at Selena's funeral, "consider me retired." This left the band's future uncertain, and Lee and Lifeson prepared an archival album, Different Stages, for release during the hiatus.
=== Pentomic organization === In 1957, the division implemented the pentomic organization, officially Reorganization of the Airborne Division (ROTAD), to better prepare for tactical nuclear war in Europe. Five battle groups, each with a headquarters and service company, five rifle companies and a mortar battery, replaced the division's three regiments of three battalions each. The division's battle groups were:
Sources: en.wikipedia.org
It activates both GIP and GLP-1 receptors. This dual action differentiates it from selective GLP-1 agonists.
It is given as a subcutaneous injection. Its long half-life supports weekly dosing.
No, it is synthetic. It contains non-natural amino acids and a fatty acid modification.
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。