Everything below concerns 合成肽. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-03-13. Numbers and descriptions here follow the published literature rather than marketing material.
The peptide activates two G protein-coupled receptors, GIPR and GLP-1R. Binding triggers adenylyl cyclase activity and raises intracellular cyclic AMP in pancreatic beta cells, which potentiates insulin release when glucose is elevated. Signaling in the central nervous system is associated with reduced appetite and lower energy intake, while effects on gastric emptying and glucagon secretion are also reported. Because activity at both receptors is retained, the pharmacological profile is often described as incretin-based rather than selective for a single receptor.
After subcutaneous injection, absorption is gradual, and peak plasma levels are generally reached within one to three days. Albumin binding extends the apparent half-life to roughly five days, which supports a weekly administration schedule. Metabolism proceeds mainly through proteolytic cleavage of the peptide backbone and beta-oxidation of the fatty acid chain, rather than through cytochrome P450 pathways. Eliminated fragments are largely recycled through general protein turnover, and excretion of intact drug in urine is minimal. These properties distinguish the molecule from short-acting incretin mimetics.
Tirzepatide is a synthetic peptide of 39 amino acids engineered from the native glucose-dependent insulinotropic polypeptide sequence. Its structure incorporates several non-natural residues and a C-terminal segment derived from glucagon-like peptide-1, together with a C20 fatty diacid moiety attached through a linker. The lipophilic side chain promotes binding to serum albumin, which slows renal clearance after administration. The compound is classified as a dual incretin receptor agonist and is supplied as a lyophilized powder for reconstitution or as a preformulated solution, depending on the presentation.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C225H348N48O68 | Approximate composition of the free peptide |
| Molecular weight | Approximately 4813 Da | Calculated for the free base |
| Structural class | Synthetic linear peptide | 39 residues with modified backbone |
| Solubility | Soluble in water and polar solvents | Behavior of the lyophilized solid |
| Typical storage temperature | -20 degrees Celsius or below | Solid form, protected from light |
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, with mass confirmation by electrospray ionisation mass spectrometry. Peptide mapping after enzymatic digestion verifies the primary sequence. Size-exclusion chromatography quantifies aggregates, while circular dichroism provides a secondary-structure fingerprint. Bioanalytical quantification in plasma uses immunoassay or LC-MS/MS. Reported purity for research-grade lots is commonly 95 percent or higher, and residual water content is checked by Karl Fischer titration.
As a peptide, tirzepatide is handled as a lyophilised solid in research settings and as a preserved solution in finished products. Aqueous solubility is pH dependent and reaches a minimum near the isoelectric point, which lies close to pH 5.4. Stock solutions are typically prepared in neutral or slightly basic buffer to limit precipitation. The solid is hygroscopic and should be equilibrated to room temperature before opening so that condensation does not form on the powder surface.
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。
当前公开资料把 tirzepatide 归为肠促胰素类受体双重激动剂。它并非激素天然变体，而是经过序列改造的工程化肽。其分子量、等电点与疏水性等基础参数已在药典和化学数据库中收录，可作为分析检测和质量研究的参照。
Tirzepatide 是一种由 39 个氨基酸组成的合成肽，分子结构上以 GIP 序列为骨架并引入脂肪酸侧链修饰，使其能够同时与葡萄糖依赖性促胰岛素多肽（GIP）受体和胰高血糖素样肽-1（GLP-1）受体结合。这种双重激动特性使它在同类肽类药物中区别于选择性 GLP-1 受体激动剂。该分子最早由一家制药公司在 2010 年代报道，随后进入糖尿病与体重管理领域的临床研究。
Research and analytical settings increasingly require documentation of peptide origin and chain of custody. Certificate of analysis documents typically report purity by chromatographic area, mass confirmation, appearance, and residual solvent or counterion content. Independent verification by an accredited laboratory is common when a material will be used in a regulated study. Open questions remain about how well compendial methods transfer between laboratories, and about which impurity thresholds are meaningful for materials not intended for clinical use.
Peptide-based pharmaceutical products such as tirzepatide require controlled temperature management to preserve structural integrity. Manufacturer labeling generally specifies refrigeration at 2 to 8 degrees Celsius before first use, with protection from light and freezing. Exposure to repeated temperature cycling can promote aggregation or deamidation, which alters the analytical profile even when the visible solution appears unchanged. Once a product is in use, the permitted storage window and temperature range are defined by the specific labeled presentation rather than by general peptide rules.
Sanders' proposed legislation include worker-owned business, the Workplace Democracy Act, employee ownership as alternative to corporations and a package to encourage employee-owned companies. Sanders associates Franklin D. Roosevelt's New Deal and Lyndon B. Johnson's Great Society as part of the democratic socialist tradition and claimed the New Deal's legacy to "take up the unfinished business of the New Deal and carry it to completion." While opponents of Sanders have used the democratic socialist label to accuse him of being too left-leaning for American politics, the theoretical and practical applications of it are based on the precept of shifting responsibility away from the national level to local decision-makers, a fundamental principle shared by the system of federalism in the United States. A democratic socialist perspective on government investment in infrastructure would support more projects with smaller-sized budgets on a local level instead of a few highly expensive ones. This view aligns with the Republican Party's fundamental identity, philosophy and agenda of local people exerting control over their own affairs. In a 2018 poll conducted by Gallup, a majority of people under the age of 30 in the United States stated that they approve of socialism. 57% of Democratic-leaning voters viewed socialism positively and 47% saw capitalism positively while 71% of Republican-leaning voters who were polled saw capitalism under a positive light and 16% viewed socialism in a positive light.
Contemporary medicine is, in general, conducted within health care systems. Legal, credentialing, and financing frameworks are established by individual governments, augmented on occasion by international organizations, such as churches. The characteristics of any given health care system have a significant impact on the way medical care is provided. From ancient times, Christian emphasis on practical charity gave rise to the development of systematic nursing and hospitals, and the Catholic Church today remains the largest non-government provider of medical services in the world. Advanced industrial countries (with the exception of the United States) and many developing countries provide medical services through a system of universal health care that aims to guarantee care for all through a single-payer health care system or compulsory private or cooperative health insurance. This is intended to ensure that the entire population has access to medical care on the basis of need rather than ability to pay. Delivery may be via private medical practices, state-owned hospitals and clinics, or charities, most commonly a combination of all three. Most tribal societies provide no guarantee of healthcare for the population as a whole. In such societies, healthcare is available to those who can afford to pay for it, have self-insured it (either directly or as part of an employment contract), or may be covered by care financed directly by the government or tribe.
Levorphanol's exceptionally high analgesic efficacy in the treatment of neuropathic pain is also conferred by its action on serotonin and norepinephrine transporters, similar to the opioids tramadol and tapentadol, and mutually complements the analgesic effect of its NMDA receptor antagonism. Levorphanol shows a high rate of psychotomimetic side effects such as hallucinations and delirium, which have been attributed to its binding to and activation of the KOR. At the same time however, activation of this receptor as well as of the DOR have been determined to contribute to its analgesic effects.
Relative to 150 mg/day bicalutamide, levels of (R)-bicalutamide are about 15% higher at a dosage of 200 mg/day and about 50% higher at a dosage of 300 mg/day. In contrast to (R)-bicalutamide, the inactive enantiomer (S)-bicalutamide is much more rapidly absorbed (as well as cleared from circulation). Steady-state concentrations of the drug are reached after 4 to 12 weeks of administration independently of dosage, with an approximate 10- to 20-fold progressive accumulation of circulating levels of (R)-bicalutamide. The relatively long time to reach steady-state is a product of the long elimination half-life of bicalutamide. With single 50 mg and 150 mg doses of bicalutamide, mean peak concentrations (Cmax) of (R)-bicalutamide are 0.77 μg/mL (1.8 μmol/L) (at 31 hours) and 1.4 μg/mL (3.3 μmol/L) (at 39 hours), respectively. At steady-state, mean circulating concentrations (Css) of (R)-bicalutamide with 50 mg/day and 150 mg/day bicalutamide are 8.85 μg/mL (20.6 μmol/L) and 21.6 μg/mL (50.2 μmol/L), respectively. In another 150 mg/day bicalutamide study, mean circulating concentrations of (R)-bicalutamide were 19.4 μg/mL (45.1 μmol/L) and 28.5 μg/mL (66.3 μmol/L) on days 28 and 84 (weeks 4 and 12) of treatment, respectively. There is wide interindividual variability, up to 15.7-fold, in steady-state (R)-bicalutamide levels with bicalutamide therapy. This is the case for all dosage levels of bicalutamide, and ranges in (R)-bicalutamide levels for different dosages show significant overlap.
This positive cooperative binding is achieved through steric conformational changes of the hemoglobin protein complex as discussed above; i.e., when one subunit protein in hemoglobin becomes oxygenated, a conformational or structural change in the whole complex is initiated, causing the other subunits to gain an increased affinity for oxygen. As a consequence, the oxygen binding curve of hemoglobin is sigmoidal, or S-shaped, as opposed to the normal hyperbolic curve associated with noncooperative binding. The dynamic mechanism of the cooperativity in hemoglobin and its relation with low-frequency resonance has been discussed.
Sources: en.wikipedia.org
=== Complications === JIA is a chronic disorder, which if neglected, can lead to serious complications. However, with regular follow-up and modern treatments, complications have reduced and outcomes improved. If inflammation is not treated, it can damage the joint, the cartilage and the bone. With the advent of modern therapies, these complications of JIA have become much less common. Children with JIA may have a reduced overall rate of growth, especially if the disease involves many joints or other body systems. This may be due to a combination of the disease itself, as well as its treatments, particularly corticosteroid use. Paradoxically, limbs where a large joint (such as the knee) is inflamed may have increased growth in the short term, leading to limb-length discrepancy (i.e. one arm or leg is slightly longer than the other). This is due to increased blood supply to the bony growth plates surrounding the inflamed joints. Bone density and bone strength may be reduced through a combination of inflammation, corticosteroid use and reduced physical activity levels. Uveitis, if left untreated, can result in scarring, glaucoma, cataracts, and even blindness. Regular monitoring allows for early detection and treatment. Steroid eye drops are usually the first line treatment for anterior uveitis. However, other treatments – many of which also treat arthritis (e.g. methotrexate, biologics) – may be required to keep the inflammation under control, and to minimise steroid use over the longer term. Long term steroid use can contribute to the development of cataracts.
== Safety issues == Care in package design is needed for food safety. A safety issue is that the cooking time given on the packaging does not apply to all microwave ovens. Setting the timer and coming back later, after the timer's alarm has sounded, could result in the popcorn being burnt and smoking badly. Microwave popcorn makers suggest that the person cooking the popcorn stay near the oven to observe the popcorn as it cooks, and take the popcorn out when the time between pops is more than a few seconds. Some microwave ovens have a specific mode designed for cooking popcorn, which either uses factory-calibrated time and power level settings, or which uses humidity or sound sensors to detect when popping has finished. The concern about microwave popcorn bags has increased in terms of the waste and their harmful impacts on the environment. The coating materials used in microwave popcorn bags can have negative effects on the environment. Researchers have detected toxic chemicals in the bags, such as perfluorinated compounds (PFCs) and their potential precursors.
== Regulation == AADC regulation, especially as it relates to L-DOPA decarboxylation, has been studied extensively. AADC has several conserved protein kinase A (PKA) and protein kinase G recognition sites, with residues S220, S336, S359, T320, and S429 all as potential phosphate acceptors. In vitro studies have confirmed PKA and PKG can both phosphorylate AADC, causing a significant increase in activity. In addition, dopamine receptor antagonists have been shown to increase AADC activity in rodent models, while activation of some dopamine receptors suppresses AADC activity. Such receptor-mediated regulation is biphasic, with an initial short term activation followed by long term activation. The short term activation is thought to proceed through kinase activation and subsequent phosphorylation of AADC, while the sensitivity of long term activation to protein translation inhibitors suggests regulation of mRNA transcription.
As an international coalition under United States command assembled in anticipation of an invasion of Iraqi-occupied Kuwait, the Iraqi regime decided to destroy as much of Kuwait's oil reserves and infrastructure as possible before withdrawing from the country. As early as December 1990, Iraqi forces placed explosive charges on Kuwaiti oil wells. The wells were systematically sabotaged beginning on January 16, 1991, when the allies commenced air strikes against Iraqi targets. On February 8, satellite images detected the first smoke from burning oil wells. The number of oil fires peaked between February 22 and 24, when the allied ground offensive began. According to the U.S. Environmental Protection Agency's report to Congress, "the retreating Iraqi army set fire to or damaged over 700 oil wells, storage tanks, refineries, and facilities in Kuwait." Estimates placed the number of oil well fires from 605 to 732. A further thirty-four wells had been destroyed by heavy coalition bombing in January. The Kuwait Petroleum Company's estimate as of September 1991 was that there had been 610 fires, out of a total of 749 facilities damaged or on fire along with an unspecified number of oil filled low-lying areas, such as "oil lakes" and "fire trenches". These fires constituted approximately 50% of the total number of oil well fires in the history of the petroleum industry, and temporarily damaged or destroyed approximately 85% of the wells in every major Kuwaiti oil field. Concerted efforts to bring the fires and other damage under control began in April 1991.
Targeted screening may be appropriate in a number of situations where hypothyroidism is common: other autoimmune diseases, a strong family history of thyroid disease, those who have received radioiodine or other radiation therapy to the neck, those who have previously undergone thyroid surgery, those with an abnormal thyroid examination, those with psychiatric disorders, people taking amiodarone or lithium, and those with a number of health conditions (such as certain heart and skin conditions). Yearly thyroid function tests are recommended in people with Down syndrome, as they are at higher risk of thyroid disease. Guidelines for England and Wales from the National Institute for Health and Care Excellence (NICE) recommend testing for thyroid disease in people with type 1 diabetes and new-onset atrial fibrillation, and suggests testing in those with depression or unexplained anxiety (all ages), in children with abnormal growth, or unexplained change in behavior or school performance. NICE also recommends screening for celiac disease in people with a diagnosis of autoimmune thyroid disease.
Sources: en.wikipedia.org
It is a synthetic linear peptide that acts as a dual agonist at the GIP and GLP-1 receptors. It combines a modified incretin backbone with a fatty diacid side chain that extends its circulation time. It is not a small-molecule drug and is not orally absorbed in its native form.
Single-receptor agents act predominantly at GLP-1R. Tirzepatide retains activity at GIPR, which is expressed in pancreatic islets, adipose tissue, and the central nervous system. The contribution of each receptor to the overall response is still an area of active study, and the relative weight of GIPR signaling in humans is not fully settled.
The fatty diacid moiety binds serum albumin, which reduces renal filtration of the active peptide. Additional resistance to enzymatic breakdown comes from non-natural residues in the backbone. Together these features produce an apparent half-life of about five days and permit weekly dosing intervals.
It is a synthetic 39-amino-acid peptide that acts on two incretin receptors, the GIP receptor and the GLP-1 receptor. It is given by subcutaneous injection and has a circulating half-life of roughly five days. It is not a small molecule and is not absorbed usefully from the gut in conventional oral form.