dual agonist raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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。
在生理层面,GIP 与 GLP-1 均为肠道内分泌细胞分泌的肠促胰素,进食后参与胰岛素分泌调节与胃排空抑制。Tirzepatide 通过同时激活这两条信号通路,使胰岛素分泌的葡萄糖依赖性增强,并延缓冲胃排空、降低食欲信号。与单一 GLP-1 激动相比,双靶点作用在血糖控制和体重变化上的效应幅度更大,但具体贡献比例仍在研究之中。
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.
Pharmacologically, tirzepatide activates two distinct G protein-coupled receptors: the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. Binding at each target triggers cyclic AMP accumulation and downstream signaling in pancreatic beta cells, adipose tissue and the central nervous system. Because the two pathways overlap only partially, the combined effect on insulin secretion, glucagon suppression and appetite signaling differs from that of selective single-receptor compounds. Affinity is not equal across the two targets, and the clinical meaning of that imbalance remains an area of active study.
| Property | Value | Notes |
|---|---|---|
| 分子类型 | 合成修饰肽 | 39 个氨基酸,含脂肪酸侧链 |
| 受体靶点 | GIP 与 GLP-1 受体 | 双重激动剂 |
| 分子量 | 约 4.8 kDa | 以游离肽计 |
| 外观 | 白色至类白色粉末 | 冻干形态常见 |
| 溶解性 | 可溶于水及水性缓冲液 | 溶解后宜低温保存 |
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.
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.
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.
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.
Bulk peptide material is normally characterised by reversed-phase high-performance liquid chromatography, which separates the target sequence from truncation products and other closely related impurities. Ultraviolet detection near 214 nanometres is common because the peptide backbone absorbs in that region. Mass spectrometry, usually electrospray ionisation coupled to a mass analyser, is used to confirm the molecular mass. Because the molecule carries a lipophilic side chain, gradient methods often need a relatively high organic modifier fraction to elute it within a practical retention window.
Like most synthetic peptides of this size, the material is commonly supplied as a lyophilised powder that appears white to off-white. It dissolves in aqueous buffers and in mixtures of water with a small proportion of organic solvent, though the fatty acid portion reduces solubility in pure water relative to short peptides. Hygroscopic behaviour is reported for many peptide powders, so weighing is usually performed quickly and under controlled humidity. Working solutions are typically prepared fresh and kept cold.
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.
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.
Mumps vaccines are vaccines which prevent mumps. When given to a majority of the population they decrease complications at the population level. Effectiveness when 90% of a population is vaccinated is estimated at 85%. Two doses are required for long term prevention. The initial dose is recommended between 12 and 18 months of age. The second dose is then typically given between two years and six years of age. Usage after exposure in those not already immune may be useful. Side effects are usually mild. It may cause "slight soreness and swelling" at the site of injection, parotisis and mild fever. More significant side effects are rare. Evidence is insufficient to link the vaccine to complications such as neurological effects (beyond "occasional orchitis and sensorineural deafness"). The vaccine should not be given to people who are pregnant or have very poor immune system function. Poor outcomes among children of mothers who received the vaccine during pregnancy, however, have not been documented. Even though the vaccine is developed in chicken cells, it is generally safe to give to those with egg allergies. Most of the developed world and many countries in the developing world include it in their immunization programs often in combination with measles and rubella vaccine known as MMR. A formulation with the previous three and the varicella (chickenpox) vaccine known as MMRV is also available. As of 2005, 110 countries provided the vaccine as part of their immunization programs.
This is to ensure that no new infections have been acquired or have developed during the period of donation. Providing the result is negative, the sperm samples can be released from quarantine and used. Common reasons for sperm rejection include suboptimal semen quality and STDs. Chromosomal abnormalities are also a cause for semen rejection, but are less common. Children conceived through sperm donation had a birth defect rate of almost a fifth compared with the general population in a 1983 study. The sperm will be checked to ensure its fecundity and also to ensure that motile sperm will survive the freezing process. If a man is accepted as a sperm donor, his sperm will generally be constantly monitored, and samples of his blood will be taken at regular intervals. A sperm bank may provide a donor with dietary supplements containing herbal or mineral substances such as maca, zinc, vitamin E, and arginine which are designed to improve the quality and quantity of the donor's semen, as well as reduce the refractory time.
== History == This cone was described by Sir Geoffrey Ingram Taylor in 1964 before electrospray was "discovered". This work followed on the work of Zeleny who photographed a cone-jet of glycerine in a strong electric field and the work of several others: Wilson and Taylor (1925), Nolan (1926) and Macky (1931). Taylor was primarily interested in the behavior of water droplets in strong electric fields, such as in thunderstorms.
== Function == S100B is glial-specific and is expressed primarily by astrocytes, but not all astrocytes express S100B. It has been shown that S100B is only expressed by a subtype of mature astrocytes that ensheath blood vessels and by NG2-expressing cells. This protein may function in neurite extension, proliferation of melanoma cells, stimulation of Ca2+ fluxes, inhibition of PKC-mediated phosphorylation, astrocytosis and axonal proliferation, and inhibition of microtubule assembly. In the developing CNS it acts as a neurotrophic factor and neuronal survival protein. In the adult organism it is usually elevated due to nervous system damage, which makes it a potential clinical marker.
==== Cell fate specification ==== Cell fate specification or cell differentiation is a process where undifferentiated cells can become a more specialized cell type. Wnt signaling induces differentiation of pluripotent stem cells into mesoderm and endoderm progenitor cells. These progenitor cells further differentiate into cell types such as endothelial, cardiac and vascular smooth muscle lineages. Wnt signaling induces blood formation from stem cells. Specifically, Wnt3 leads to mesoderm committed cells with hematopoietic potential. Wnt1 antagonizes neural differentiation and is a major factor in self-renewal of neural stem cells. This allows for regeneration of nervous system cells, which is further evidence of a role in promoting neural stem cell proliferation. Wnt signaling is involved in germ cell determination, gut tissue specification, hair follicle development, lung tissue development, trunk neural crest cell differentiation, nephron development, ovary development and sex determination. Wnt signaling also antagonizes heart formation, and Wnt inhibition was shown to be a critical inducer of heart tissue during development, and small molecule Wnt inhibitors are routinely used to produce cardiomyocytes from pluripotent stem cells.
Sources: en.wikipedia.org
On 3 January 1945, the 82nd Airborne Division conducted a counterattack. On the first day's fighting the 82nd Airborne overran the 62nd Volksgrenadiers and the 9th SS Panzer's positions capturing 2,400 prisoners. The 82nd Airborne suffered high casualties in the process. The attached 551st Parachute Infantry Battalion was all but destroyed during these attacks. Of the 826 men who went into the Ardennes, only 110 came out. Having lost its charismatic leader Lt. Colonel Joerg, and almost all its men either wounded, killed, or frostbitten, the 551 was never reconstituted. The few soldiers who remained were later absorbed into units of the 82nd Airborne. After several days of fighting, the destruction of the 62nd Volksgrenadiers, and what had been left of the 9th SS Panzer Division was complete. For the 82nd Airborne Division the first part of the Battle of the Bulge had ended.
=== Liquid MIC storage === The Bhopal UCIL facility housed three underground 68,000-litre (18,000-US-gallon) liquid MIC storage tanks: E610, E611, and E619. In the months leading up to the December leak, liquid MIC production was in progress and being used to fill these tanks. UCC safety regulations specified that no one tank should be filled more than 50% (about 30 tons) with liquid MIC. Each tank was pressurized with inert nitrogen gas. This pressurization allowed liquid MIC to be pumped out of each tank as needed and also kept impurities and moisture out of the tanks. In late October 1984, tank E610 lost the ability to effectively contain most of its nitrogen gas pressure, which meant that the liquid MIC contained within could not be pumped out. At the time of this failure, tank E610 contained 42 tons of liquid MIC. Shortly after this failure, MIC production was halted at the Bhopal facility, and parts of the plant were shut down for maintenance. Maintenance included the shutdown of the plant's flare tower so that a corroded pipe could be repaired. With the flare tower still inoperable, production of carbaryl was resumed in late November using MIC stored in the two tanks still in service. An attempt to re-establish pressure in tank E610 on 1 December failed, so the 42 tons of liquid MIC contained within still could not be pumped out of it.
== Chemistry == THC is a molecule that combines polyketides (derived from acetyl CoA) and terpenoids (derived from isoprenylpyrophosphate). It is hydrophobic with very low solubility in water, but good solubility in many organic solvents. As a phytochemical, THC is assumed to be involved in the plant's evolutionary adaptation against insect predation, ultraviolet light, and environmental stress.
The solutions for molecules, such as methane, provide exact representations of their electronic structure which are unobtainable by experimental methods. Instead of four discrete σ-bonds from carbon to each hydrogen atom, theory predicts a set of four bonding molecular orbitals which are delocalized across the entire molecule. Similarly, the true electronic structure of 1,3-butadiene shows delocalized π-bonding molecular orbitals stretching through the entire molecule rather than two isolated double bonds as predicted by a simple Lewis structure. A complete electronic structure offers great predictive power for organic transformations and dynamics, especially in cases concerning aromatic molecules, extended π systems, bonds between metal ions and organic molecules, molecules containing nonstandard heteroatoms like selenium and boron, and the conformational dynamics of large molecules such as proteins wherein the many approximations in chemical formalisms make structure and reactivity prediction impossible. An example of how electronic structure determination is a useful tool for the physical organic chemist is the metal-catalyzed dearomatization of benzene. Chromium tricarbonyl is highly electrophilic due to the withdrawal of electron density from filled chromium d-orbitals into antibonding CO orbitals, and is able to covalently bond to the face of a benzene molecule through delocalized molecular orbitals. The CO ligands inductively draw electron density from benzene through the chromium atom, and dramatically activate benzene to nucleophilic attack.
Other techniques for determining the dosage of CPA have validated this extrapolation, for instance affinity studies and prostatic CPA levels. The affinity of CPA for the AR is around 20-fold lower than that of DHT, and an excess of CPA levels of around 20 to 30 times those of DHT would hence be expected to maximally neutralize androgen signaling. In accordance, different publications have stated based on preclinical experiments that a 2- to 5-fold excess of CPA can inhibit the effects of testosterone by 50%, a 3- to 10-fold excess of CPA can reduce the effects of "potent androgens" (presumably testosterone and/or DHT) by 50%, and a 10-fold excess of CPA can inhibit the effects of testosterone by "almost 100%". High-dose CPA has been found to achieve prostatic levels that are at least 30-fold those of DHT. One study found that levels of CPA in the prostate gland in men being treated with 200 mg/day oral CPA were about 28 times those of DHT. In accordance with the preceding findings, it has been stated that oral doses of CPA of at least 300 mg/day may achieve a combined androgen blockade action in the treatment of prostate cancer. At a dosage of CPA of 100 mg/day in men with prostate cancer, circulating levels of CPA (e.g., 350 ng/mL) are on the order of 200-fold higher than circulating levels of testosterone (e.g., 100 ng/dL). In men who have undergone orchiectomy, 50 mg/day oral CPA results in a 500-fold excess of circulating CPA relative to circulating testosterone.
Sources: en.wikipedia.org
In 2022, the University of North Carolina established two student awards in his name, funded in part by gifts from Wadden and his sister, Anne Wadden Peck: one for training in clinical and health psychology and another for distinguished research in behavioral medicine and health psychology.
== Specificity == Algicidal activity can be highly strain-specific and sometimes appears random or unexplained. Current studies have found that particle-associated bacteria tend to have broader algicidal activity, while free-living bacteria are often more species-specific. Algicidal bacteria with low host specificity may occupy a broader ecological niche as they can interact with and utilize organic matter from multiple algal species. However, highly specific bacteria may be more efficient in targeting particular algal hosts. Specificity does not necessarily determine bacterial abundance, but rather reflects different ecological strategies such as generalist versus specialist lifestyles.
== Epidemiology == The most commonly quoted figure for the prevalence of SCID is around one in 100,000 births, although this is regarded by some to be an underestimate of the true prevalence; some estimates predict that the prevalence rate is as high as one in 50,000 live births. A figure of about one in 65,000 live births has been reported for Australia. Due to the particular genetic nature of SCID, a higher prevalence may be found in certain regions and associated cultures where higher rates of consanguineous mating occur (i.e. mating between blood relatives). A Moroccan study reported that consanguineous parenting was observed in 75% of the families of Moroccan SCID patients. Recent studies indicate that one in every 2,500 children in the Navajo population inherit severe combined immunodeficiency. This condition is a significant cause of illness and death among Navajo children. Ongoing research reveals a similar genetic pattern among the related Apache people.
When taken in normal therapeutic doses, paracetamol has been shown to be safe. Following a therapeutic dose, it is mostly converted to nontoxic metabolites via Phase II metabolism by conjugation with sulfate and glucuronide, with a small portion being oxidized via the cytochrome P450 enzyme system. Cytochromes P450 2E1 and 3A4 convert approximately 5% of paracetamol to a highly reactive intermediary metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Under normal conditions, NAPQI is detoxified by conjugation with glutathione to form cysteine and mercapturic acid conjugates. In cases of paracetamol overdose, the sulfate and glucuronide pathways become saturated, and more paracetamol is shunted to the cytochrome P450 system to produce NAPQI. As a result, hepatocellular supplies of glutathione become depleted, as the demand for glutathione is higher than its regeneration. NAPQI therefore remains in its toxic form in the liver and reacts with cellular membrane molecules, resulting in widespread hepatocyte damage and death, leading to acute liver necrosis. In animal studies, the liver's stores of glutathione must be depleted to less than 70% of normal levels before liver toxicity occurs.
Sources: en.wikipedia.org
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。
分子上的脂肪酸侧链使其与血浆白蛋白结合增强,显著延长循环半衰期。半衰期延长后,稳定血药浓度可在较长的给药间隔内维持,因此常见用法为每周一次。
同时激活两条肠促胰素通路可能在胰岛素分泌、胃排空和食欲调节上产生叠加效应。与单靶点相比,临床研究中观察到的血糖与体重变化幅度通常更明显,但各通路的具体贡献比例尚无定论。
It is a synthetic peptide that activates both the GIP and GLP-1 receptors, making it a dual agonist. Approved products are given by injection rather than by mouth. It is not a small molecule and does not belong to the older sulfonylurea or thiazolidinedione families.