The short version of 双受体激动 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-27 and is reviewed periodically as new material appears.
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.
Purified material is typically handled as a lyophilized powder kept at or below minus twenty degrees Celsius, shielded from light and moisture. In that state the solid remains stable for extended periods, although repeated freeze-thaw cycling can encourage aggregation. Once dissolved, aqueous solutions are less durable and are generally held cold and used within a brief window. Buffer composition, pH and ionic strength all influence degradation rates, and mildly acidic to neutral conditions are commonly examined. Actual shelf life depends on formulation, concentration and container, so stability limits are established experimentally rather than assumed.
Verification of research-grade material involves checking purity, sequence and counter-ion content against a certificate of analysis. Reported purity figures usually reflect chromatographic area percentage and do not by themselves establish biological activity. Independent laboratories may repeat mass confirmation and peptide mapping to detect substitutions or truncations. Open questions concern how residual solvents, trace metals and subtle conformational variants affect measured behavior, and how consistently different suppliers define their specifications. Documentation of analytical methods matters as much as the headline purity number when results are compared across studies.
Routine characterization relies on reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry, to confirm identity and estimate purity. Peptide mapping after enzymatic digestion verifies the amino acid sequence and locates appended groups such as the fatty acid chain. Size-exclusion chromatography detects aggregates and fragments, while ion-exchange chromatography resolves charge variants. Circular dichroism and nuclear magnetic resonance supply secondary and higher-order structural information in research settings. No single technique covers every attribute, so laboratories combine orthogonal methods and compare outcomes against a reference standard where one exists.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Modified synthetic peptide | 39-residue backbone with non-natural residues |
| Receptor targets | GIP and GLP-1 | Dual incretin receptor agonist |
| Approximate molecular mass | 4,813 Da | Calculated from the peptide sequence |
| Administration route | Subcutaneous injection | Weekly schedule in approved products |
| Albumin binding | Present | Mediated by a C20 fatty diacid side chain |
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。
脂肪酸侧链的存在使该肽与血浆白蛋白结合能力增强，从而延长循环半衰期，支持每周一次给药的用药间隔。白蛋白结合同时改变组织分布特征，减慢肾脏清除速度。该设计思路在多种长效肽类药物中被反复采用，属于既定的药代动力学策略。
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.
At the receptor level, the compound binds both GIP and GLP-1 receptors and triggers downstream signalling that raises cyclic AMP in target cells. GLP-1 receptor activation is associated with glucose-dependent insulin release, slower gastric emptying, and reduced appetite signalling. GIP receptor activation contributes effects that are less completely characterised, and how much each receptor adds to the overall clinical response is still an open question. The two pathways appear to interact in a complementary rather than a purely additive way.
An extended fatty diacid moiety promotes binding to serum albumin, which slows renal clearance and extends the circulating half-life to roughly five days. That property supports once-weekly administration and largely explains the dosing interval described in clinical reports. Published data come mainly from large randomised programmes that evaluated glycaemic control and body weight over periods of many months. Long-term outcomes beyond those trial windows, including what happens after treatment stops, remain an active area of investigation.
Degradation pathways for tirzepatide include deamidation, oxidation, and aggregation, which are common for therapeutic peptides. These processes can be monitored by size-exclusion chromatography (SEC) for aggregates and ion-exchange chromatography for charge variants. Forced degradation studies under acidic, basic, oxidative, and thermal stress help identify potential impurities. The exact stability profile depends on formulation, concentration, and container-closure system.
Analytical characterization of tirzepatide typically employs reversed-phase high-performance liquid chromatography (RP-HPLC) for purity assessment and peptide mapping. Mass spectrometry, often coupled with electrospray ionization, confirms molecular weight and sequence integrity. Amino acid analysis and capillary electrophoresis may also be used to detect impurities or degradation products. These methods are essential for batch release and stability studies.
Storage recommendations for tirzepatide generally specify refrigeration at 2–8 °C to maintain stability. The peptide should be protected from light and kept in its original packaging to prevent aggregation or adsorption. Freezing is not recommended because freeze-thaw cycles can cause aggregation or precipitation. Once dispensed, storage conditions and in-use periods follow product-specific labeling, which may allow room temperature storage for a limited time.
Gamma delta T cells (γδ T cells) represent a small subset of T cells which possess a γδ TCR rather than the αβ TCR on the cell surface. The majority of T cells express αβ TCR chains. This group of T cells is much less common in humans and mice (about 2% of total T cells) and are found mostly in the gut mucosa, within a population of intraepithelial lymphocytes. In rabbits, sheep, and chickens, the number of γδ T cells can be as high as 60% of total T cells. The antigenic molecules that activate γδ T cells are still mostly unknown. However, γδ T cells are not MHC-restricted and seem to be able to recognize whole proteins rather than requiring peptides to be presented by MHC molecules on APCs. Some murine γδ T cells recognize MHC class IB molecules. Human γδ T cells that use the Vγ9 and Vδ2 gene fragments constitute the major γδ T cell population in peripheral blood. These cells are unique in that they specifically and rapidly respond to a set of nonpeptidic phosphorylated isoprenoid precursors, collectively named phosphoantigens, which are produced by virtually all living cells. The most common phosphoantigens from animal and human cells (including cancer cells) are isopentenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate (DMPP). Many microbes produce the active compound hydroxy-DMAPP (HMB-PP) and corresponding mononucleotide conjugates, in addition to IPP and DMAPP. Plant cells produce both types of phosphoantigens. Drugs activating human Vγ9/Vδ2 T cells comprise synthetic phosphoantigens and aminobisphosphonates, which upregulate endogenous IPP/DMAPP.
==== United States 1909–1912, 1924–1925, & 1936–1937 ==== During the period of Jung's collaboration with Freud, both visited the US in 1909 to lecture at Clark University, Worcester, Massachusetts, where both were awarded honorary degrees. In 1912, Jung gave a series of lectures at Fordham University, New York, which were published later in the year as Psychology of the Unconscious. Jung made a more extensive trip westward in the winter of 1924–25, financed and organized by Fowler McCormick and George Porter. Of particular value to Jung was a visit with Chief Mountain Lake of the Taos Pueblo near Taos, New Mexico. Jung made another trip to America in 1936, receiving an honorary degree at Harvard, and giving lectures in New York and New England for his growing group of American followers. He returned in 1937 to deliver the Terry Lectures at Yale University, later published as Psychology and Religion.
== History == Epidemics of meningococcal A meningitis, which is a bacterial infection of the thin lining surrounding the brain and spinal cord, have swept across 26 countries in sub-Saharan Africa for a century, killing and disabling young people every year. The disease is highly feared on the continent; it can kill or cause severe brain damage in a child within hours. Epidemics usually start at the beginning of the calendar year when dry sands from the Sahara Desert begin blowing southward. The largest meningitis epidemic in African history swept across sub-Saharan Africa from 1996 to 1997, numbering 250,000 new cases and taking 25,000 lives. Three years later, the World Health Organization (WHO) held a technical consultation in Cairo, Egypt with African ministers of health and global health leaders to discuss meningitis and the development of a new vaccine. At that meeting, representatives from eight African countries issued a statement saying that the development of a meningococcal vaccine to prevent epidemics was a high priority for them, and concluded that a conjugate meningococcal vaccine would have the potential to prevent future epidemics. They estimated that the new vaccine could become available in three to seven years for US$0.40 to $1 a dose, providing protection for at least ten years. A year later, in 2001, the Bill & Melinda Gates Foundation provided a ten-year, $70 million grant to establish the Meningitis Vaccine Project, a partnership between PATH and WHO.
=== Analogues === Analogues of DET include dimethyltryptamine (DMT), dipropyltryptamine (DPT), methylethyltryptamine (MET), methylpropyltryptamine (MPT), ethylpropyltryptamine (EPT), 4-HO-DET, 5-HO-DET, 6-HO-DET, 4-AcO-DET, ethocybin (4-PO-DET or CEY-19), 6F-DET, and 2-Me-DET.
Sources: en.wikipedia.org
The two substrates of this enzyme are (−)-menthol and oxidised nicotinamide adenine dinucleotide phosphate (NADP+). Its products are (−)-menthone, reduced NADPH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (−)-menthol:NADP+ oxidoreductase. This enzyme is also called monoterpenoid dehydrogenase. This enzyme participates in monoterpenoid biosynthesis.
=== Tissue scaffolding === The temperature-based phase behavior of ELPs can be utilized to produce stiff networks that may be compatible with cellular regeneration applications. At high concentrations (weight percent exceeding 15%), the ELP transition from a linear state to a spherical aggregate state above the transition temperature is arrested, leading to the formation of brittle gels. These otherwise brittle networks can then be modified chemically, via oxidative coupling, to yield hydrogels which can sustain high levels of mechanical stress and strain. Also, the modified gel networks contain pores, through which important cell-sustaining compounds can easily be delivered. Such strong hydrogels, when bathed in minimal cell media, have been found to promote the growth of human mesencyhmal stem cell populations. The ability of these arrested ELP networks to promote cell growth may prove indispensable in the production of tissue scaffolds that promote cartilage production, for example. Such an intervention may prove useful in the treatment of bone disease and rheumatoid arthritis.
Ab initio quantum mechanical methods simulate liquids using only the laws of quantum mechanics and fundamental atomic constants. In contrast with classical molecular dynamics, the intermolecular force fields are an output of the calculation, rather than an input based on experimental measurements or other considerations. In principle, ab initio methods can simulate the properties of a given liquid without any prior experimental data. However, they are very expensive computationally, especially for large molecules with internal structure.
Sources: en.wikipedia.org
== Structure == Osteocytes have a stellate shape, approximately 7 micrometers deep and wide by 15 micrometers in length. The cell body varies in size from 5–20 micrometers in diameter and contain 40–60 cell processes per cell, with a cell to cell distance between 20–30 micrometers. A mature osteocyte contains a single nucleus that is located toward the vascular side and has one or two nucleoli and a membrane. The cell also exhibits a reduced size endoplasmic reticulum, Golgi apparatus and mitochondria, and cell processes that radiate largely towards the bone surfaces in circumferential lamellae, or towards a haversian canal and outer cement line typical of osteons in concentric lamellar bone. Osteocytes form an extensive lacunocanalicular network within the mineralized collagen type I matrix, with cell bodies residing within lacunae, and cell/dendritic processes within channels called canaliculi.
Aspirin Ibuprofen (Advil, Nurofen) Naproxen (Aleve) There are several potential pharmacokinetic interactions between the various individual SSRIs and other medications. Most of these arise from the fact that every SSRI can inhibit certain P450 cytochrome enzymes.
Peukert argued in his essay that the late 19th and early 20th centuries had seen tremendous scientific and technological change together with, in Germany, the growth of the welfare state, which had created widespread hopes both within the government and in society that “utopia” was at hand and soon all social problems would be solved. Peukert wrote:"From the 1890s...the conviction that social reform was necessary was increasingly outflanked and overtaken by the belief that all social problems could find their rational solution through state intervention and scientific endeavor...The dream of a final solution to the social problem resonated in the plans of the 'social engineers', regardless of whatever they were active as youth welfare workers, social hygienists or city planners. Just as medicine had put paid to bacteria, so too, the union of science and social technology in public interventions would make all social problems disappear". Peukert wrote that by the beginning of the 20th century, the pattern of death had changed from being common amongst young people to being only common amongst the old, and this "banishment of death from everyday life" dramatically increased the prestige of science so that it was believed would soon solve all social problems. At the same time, owing to the great prestige of science, a scientific racist, Social Darwinist and eugenicist worldview which declared some people to be more biologically “valuable” than others was common amongst German elites.
Sources: en.wikipedia.org
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.
A fatty diacid side chain promotes reversible binding to serum albumin. This association slows renal clearance and protects the peptide from rapid enzymatic degradation. The result is a prolonged circulation time that supports weekly administration.
The first regulatory approval, for type 2 diabetes, was granted in the United States in 2022. An additional approval for chronic weight management followed in 2023. Availability and approved indications vary by country and are set by each national regulator.
Liquid chromatography combined with mass spectrometry is the most common approach. Digestion followed by peptide mapping verifies the sequence and modification sites. Results are judged against a reference standard or a theoretically calculated mass.