GLP-1 receptor comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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。
Tirzepatide is a synthetic linear peptide of 39 amino acids that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Its sequence derives from native GIP but incorporates non-natural residues and a C20 fatty diacid moiety linked to a lysine side chain. The lipophilic chain promotes albumin binding, which slows renal clearance and extends circulation time. The unmodified peptide has a molecular formula of C225H348N48O68 and a molecular mass near 4,813 daltons.
Receptor activation by tirzepatide raises intracellular cyclic AMP through Gs-coupled signalling at both targets. At the GLP-1 receptor the downstream effect includes glucose-dependent insulin release, suppressed glucagon secretion, delayed gastric emptying, and reduced appetite signalling in the hypothalamus. GIP receptor engagement adds insulinotropic activity and appears to influence lipid handling in adipose tissue. Because both receptors are stimulated at the same time, the pharmacological profile differs from that of selective GLP-1 receptor agonists, and the relative contribution of each arm remains an area of active investigation.
Clinical development proceeded through large phase 3 programmes in type 2 diabetes and in obesity or overweight with at least one weight-related comorbidity. Regulatory approvals followed in several jurisdictions for both indications. Weekly subcutaneous dosing reflects an elimination half-life of roughly five days. Open questions include the durability of metabolic effects after treatment stops, long-term cardiovascular and hepatic outcomes beyond completed trials, and whether the dual mechanism confers benefits independent of total receptor occupancy. Published literature continues to expand on these points. Substantial uncertainty remains about interindividual variability in response.
| 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 |
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.
Long-term storage of lyophilised peptide powder is generally at minus twenty degrees Celsius or colder, with desiccant and protection from light. Short-term storage at two to eight degrees Celsius is common during active use. In solution, stability depends strongly on pH, concentration, and the presence of preservatives, and hydrolysis or aggregation can develop over weeks. Published stability data specific to this molecule are limited, so recommended conditions for research material are usually extrapolated from general peptide handling practice rather than from a dedicated study.
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.
Cold-chain handling is standard for formulated product, with dry powder stored frozen and ready-to-use solutions refrigerated. Light exposure is minimized because photodegradation of certain amino acid side chains is possible. Shipping and temperature-excursion studies are used to establish whether short deviations affect quality attributes. Documentation supplied with research material usually includes a certificate of analysis listing purity, identity confirmation, and water or residual solvent content. Users are expected to confirm that material meets the stated specification before use.
Identity and purity of tirzepatide are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Because the molecule carries several modifications, gradient conditions are adjusted to resolve the intact peptide from deamidation and oxidation products. Enzymatic digestion followed by peptide mapping confirms the primary sequence and locates specific modifications. Quantitation in biological matrices typically uses liquid chromatography with tandem mass spectrometry after solid-phase extraction. Immunoassays are used less often, since antibody cross-reactivity with closely related peptides can bias results.
Common degradation routes include hydrolysis of labile amide bonds, deamidation of asparagine and glutamine residues, oxidation of methionine and tryptophan, and non-covalent aggregation. Aggregates can form during freeze-thaw cycling, at elevated pH, or when peptide concentration is high. Each route produces characteristic chromatographic or mass shifts that are tracked during stability studies. Whether a given minor impurity alters biological activity is often an open question, and specification limits are typically set on identity and purity rather than on functional data for trace species.
Lyophilized material is generally held at -20 degrees Celsius or lower, desiccated and protected from light, where it remains stable for extended periods. Reconstituted or ready-to-use solution is usually kept at 2 to 8 degrees Celsius with minimal agitation. Repeated freeze-thaw cycles should be avoided because they promote aggregation and reduce the soluble monomer fraction. Shipment of frozen solid commonly uses dry ice, while refrigerated liquid moves with validated cold packs. Stability beyond documented periods is not established.
Characterization of the peptide relies on reversed-phase high-performance liquid chromatography for purity and related-substance profiling, with ultraviolet detection near 214 nanometers. Mass spectrometry confirms molecular mass and reveals modifications such as oxidation or deamidation. Peptide mapping after enzymatic digestion verifies the amino acid sequence, while amino acid analysis supplies compositional data. Circular dichroism and infrared spectroscopy are used to assess secondary structure, particularly the alpha-helical content that influences aggregation behavior in solution.
==== Pancreatitis ==== The evidence suggesting a link between benzodiazepines (and Z-Drugs) and pancreatic inflammation is very sparse and limited to a few observational studies from Taiwan. A criticism of confounding can be applied to these findings as with the other controversial associations above. Further well-designed research from other populations, as well as a biologically plausible mechanism, is required to confirm this association.
Bossa nova is also a well-known style of Brazilian music developed and popularized in the 1950s and 1960s. The phrase "bossa nova" means literally 'new trend'. A lyrical fusion of samba and jazz, bossa nova acquired a large following starting in the 1960s.
=== Socioeconomic status === It is much more common for young people who come from a racial or ethnic minority, or for those who have a lower socioeconomic status, to be overweight and to engage in less healthy behaviors and sedentary activities.
Sources: en.wikipedia.org
Human-to-human transmission of SARS‑CoV‑2 was confirmed on 20 January 2020 during the COVID-19 pandemic. Transmission was initially assumed to occur primarily via respiratory droplets from coughs and sneezes within a range of about 1.8 metres (6 ft). Laser light scattering experiments suggest that speaking is an additional mode of transmission and a far-reaching one, indoors, with little air flow. Other studies have suggested that the virus may be airborne as well, with aerosols potentially being able to transmit the virus. During human-to-human transmission, between 200 and 800 infectious SARS‑CoV‑2 virions are thought to initiate a new infection. If confirmed, aerosol transmission has biosafety implications because a major concern associated with the risk of working with emerging viruses in the laboratory is the generation of aerosols from various laboratory activities which are not immediately recognisable and may affect other scientific personnel. Indirect contact via contaminated surfaces is another possible cause of infection. Preliminary research indicates that the virus may remain viable on plastic (polypropylene) and stainless steel (AISI 304) for up to three days, but it does not survive on cardboard for more than one day or on copper for more than four hours. The virus is inactivated by soap, which destabilises its lipid bilayer. Viral RNA has also been found in stool samples and semen from infected individuals.
It is generally advised that when patients have a low initial CD4 T cell count and OI at the time of their HIV diagnosis, they receive treatment to control the OIs before HAART is initiated approximately two weeks later. This is true for most OIs, except for OIs involving the central nervous system.
=== 2000s === Stanton was drafted by Essendon with the thirteenth overall selection in the 2003 national draft, Essendon's second pick overall in the draft. Due to many key players being injured in the 2004 pre-season, Stanton was immediately brought into the Essendon team for the round 1 match against Port Adelaide where the Bombers were comfortably defeated by 96 points. Stanton was the round nomination for the Rising Star after the round 20 win against Collingwood. Stanton started his 2005 season by changing to the number 24 jumper, previously worn by former Essendon great Joe Misiti. Stanton had a strong season, in the 19 games that he played, he averaged 18 possessions and kicked 13 goals. In just his second year of football he showed much improvement from his debut season, Stanton finished third in the 2005 Crichton Medal behind Mark Johnson and Jason Johnson with 253 votes. Stanton worked hard during the pre-season, and was able to increase his physical size. During 2006, he played a different role on the wing, opposite Scott Camporeale. During a horror season which netted only three wins and a draw for Essendon (one of which was against reigning premiers Sydney), Stanton was one of only three players in the team who played in every game that season. Stanton averaged 22 possessions and kicked 12 goals finishing fourth in the 2006 Crichton Medal with 196 votes. Stanton became a far more prominent player for the Bombers in 2007, he averaged a career-high 25 possessions in the first 10 rounds of the season.
== Sources == Latimer WM and Rodebush WH. (1920) "Polarity and Ionization from the Standpoint of the Lewis Theory of Valence", J. Am. Chem. Soc., 42, 1419–1433. Huggins ML. (1936) J. Org. Chem., 1, 407–456. Pauling L and Niemann C. (1939) J. Am. Chem. Soc., 61, 1860–1867. Huggins M. (1943) "The structure of fibrous proteins", Chem. Rev., 32, 195–218. Huggins ML. (1971) Angew. Chem. Int. Ed., 10, 147–152. Huggins ML. (1980) Chem. Tech., 10, 422.
Sources: en.wikipedia.org
== Adverse effects and contraindications == Like other antiarrhythmics, ibutilide can lead to abnormal heart rhythms due to its ability to prolong the QT interval, which can lead to the potentially fatal abnormal heart rhythm known as torsades de pointes. Consequently, the drug is contraindicated in patients that are likely to develop abnormal heart rhythms; this includes individuals who have previously experienced polymorphic ventricular tachycardia, have a prolonged QT interval, sick sinus syndrome, or have recently had a myocardial infarction, among other conditions.
== History == Photoionization has a long history of use in mass spectrometry experiments, though mostly for research purposes and not for sensitive analytical applications. Pulsed lasers have been used for non-resonant multiphoton ionization (MPI), resonance-enhanced MPI (REMPI) using tunable wavelengths, and single-photon ionization using sum frequency generation in non-linear media (usually gas cells). Non-laser sources of photoionization include discharge lamps and synchrotron radiation. The former sources were not adaptable to high sensitivity analytical applications because of low spectral brightness in the former case and large "facility-size" in the latter case. Meanwhile, photoionization has been used for GC detection and as a source for ion mobility spectrometry for many years suggesting the potential for use in mass spectrometry. The first development of APPI for LC/MS was reported by Robb, Covey, and Bruins and by Syage, Evans, and Hanold in 2000. APPI sources were commercialized shortly thereafter by Syagen Technology and made available for most commercial MS systems and by Sciex for their line of MS instruments. Concurrent to the development of APPI was a similar use of a VUV source for low pressure photoionization (LPPI) by Syage and coworkers that accepted atmospheric pressure gas phase samples but stepped down the pressure for ionization to about 1 torr (~100 Pa) before further pressure reduction for introduction into a MS analyzer. This photoionization method is well suited as an interface between gas chromatography (GC) and MS.
Hence, in rats, vosilasarm is a potent full agonist of the levator ani muscle but a partial agonist and antagonist of the prostate and seminal vesicles, and is strongly selective for stimulating the levator ani muscle over the prostate gland. In young male cynomolgus monkeys, vosilasarm, at oral doses of 0.01 mg/kg/day, 0.1 mg/kg/day, and 1 mg/kg/day for 28 days, dose-dependently stimulated body weight (+10% at ≥0.1 mg/kg/day) and numerically increased lean body mass. The lack of statistical significance was likely due to the small sample sizes per dosing group (n=3 each). No data on vosilasarm and lean body mass in humans have been published as of 2022.
== Xenon-124 == Xenon-124 is an isotope of xenon that undergoes double electron capture to tellurium-124 with a very long half-life of 1.1×1022 years, approximately 12 orders of magnitude longer than the age of the universe. This decay was observed in the XENON1T detector in 2019, and is the slowest one ever directly observed. (Even slower decays of other nuclei have been measured, but by detecting decay products that have accumulated over billions of years rather than observing them directly.)
== Knudsen cell == The Knudsen cell is used to measure the vapor pressures of a solid with very low vapor pressure. Such a solid forms a vapor at low pressure by sublimation. The vapor slowly effuses through a pinhole, and the loss of mass is proportional to the vapor pressure and can be used to determine this pressure. The heat of sublimation can also be determined by measuring the vapor pressure as a function of temperature, using the Clausius–Clapeyron relation.
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 is a dual GIP and GLP-1 receptor agonist, frequently grouped with incretin-based peptide therapeutics. It is a peptide rather than a small molecule and is given by subcutaneous injection.