肠促胰素 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-31. Anything still debated is marked as such rather than presented as settled.
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。
Published work supports the view that engaging two incretin receptors produces changes in glucose handling and body weight larger than those seen with single-receptor activation. Why that difference arises is not fully settled. Open questions include how much of the observed weight effect depends on central versus peripheral signaling, and whether the two receptors form interacting complexes. Most reported findings come from controlled trials and animal models, and translation between species is imperfect. Further research is expected to refine these points over time.
Tirzepatide is a synthetic peptide built from 39 amino acid residues. Its sequence is related to human glucose-dependent insulinotropic polypeptide, with modifications that include a C-terminal extension and a C20 fatty diacid joined through a linker. Those changes raise the molecule's affinity for serum albumin, which slows renal filtration and lengthens the time it stays in circulation. The free base has an average molecular mass near 4813.5 daltons. The compound is made by solid-phase peptide synthesis followed by chromatographic purification.
| 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 |
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.
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 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.
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.
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.
Visa requirements for Mexican citizens are administrative entry restrictions by the authorities of other states placed on citizens of Mexico. As of 2026, Mexican citizens have visa-free or visa on arrival access to 157 countries and territories, ranking the Mexican passport 22nd in the world according to the Henley Passport Index.
On July 29, 1977, H.F., a 51-year-old teacher, was attempting to remove a casserole dish from her new 600-watt microwave oven. The oven signaled the end of the heating cycle, but the light and the cooking blower were on. During retrieval of the dish, she inserted two thirds of her bare forearms into the oven, for a total time of about five seconds. The oven was still operating. She felt "hot pulsating sensation" and burning in fingers and fingernails and a sensation of "needles" over the exposed areas. Jabbing pain, swelling, and red-orange discoloration of dorsal sides of both hands and forearms appeared shortly afterwards. The next day she sought medical help. Since then, she has undergone treatment with oral and topical cortisone, Grenz rays, ultrasound, and later acupuncture, without relief. Symptoms persisted, including high sensitivity to radiant heat (sun, desk lamp, etc.) and growing intolerance to pressure of clothes and to touch in hands and forearms. Neurological examinations in 1980 and 1981 did not yield a definite diagnosis. Neuronal latencies were within norm. Electromyography discovered denervation in the median nerve, ulnar nerve, and radial nerve on both arms. Severe reduction of number of sweat glands in the finger pulps, in comparison with a random control, was also found.
Bioarchaeology (osteoarchaeology, osteology or palaeo-osteology) in Europe describes the study of biological remains from archaeological sites. In the United States it is the scientific study of human remains from archaeological sites. The term was minted by British archaeologist Grahame Clark who, in 1972, defined it as the study of animal and human bones from archaeological sites. Jane Buikstra came up with the current US definition in 1977. Human remains can inform about health, lifestyle, diet, mortality and physique of the past. Although Clark used it to describe just human remains and animal remains, increasingly archaeologists include botanical remains. Bioarchaeology was largely born from the practices of New Archaeology, which developed in the United States in the 1970s as a reaction to a mainly cultural-historical approach to understanding the past. Proponents of New Archaeology advocate testing hypotheses about the interaction between culture and biology, or a biocultural approach. Some archaeologists advocate a more holistic approach that incorporates critical theory.
=== 2020–present === In January 2020, Merck acquired ArQule, developer of ARQ 531, an oral Bruton's tyrosine kinase (BTK) inhibitor, for $2.7 billion. In March 2020, Merck was one of ten companies recognised at the inaugural Manufacturing Awards by New Jersey Business magazine and the New Jersey Business and Industry Association. In June 2020, Merck acquired Themis Bioscience, a company focused on vaccines and immune-modulation therapies for infectious diseases including COVID-19 and cancer. Also in June 2020, Merck Animal Health acquired Quantified Ag, a data and analytics company that monitors cattle body temperature and movement in order to detect illness early. In August 2020, Merck Animal Health acquired IdentiGEN, engaged in DNA-based animal traceability. In September 2020, Merck acquired $1 billion of Seattle Genetics common stock, and agreed to co-develop ladiratuzumab vedotin. In November 2020, Merck announced it would acquire VelosBio for $2.75 billion, developer of VLS-101, an antibody-drug conjugate designed to target Tyrosine kinase-like orphan receptor 1 (ROR1) in both hematological and solid tumors. VLS-101 is currently Phase I and Phase II clinical trials. The company also announced it would acquire OncoImmune for $425 million and its phase 3 candidate, CD24Fc, used in the treatment of patients with severe and critical COVID-19. In February 2021, Merck Animal Health acquired PrognostiX Poultry. In April 2021, Merck acquired Pandion Therapeutics for $1.85 billion, expanding its offering in treating autoimmune diseases. In June 2021, the U.S.
Although this can result in high prolactin levels in some assay tests, macroprolactin is biologically inactive and will not cause symptoms typical of hyperprolactinemia. In those who are asymptomatic or without obvious causes of hyperprolactinemia, macroprolactin should be assessed and ruled out. However, in patients with abnormally high levels of serum prolactin, false negative results that indicates a low level of prolactin may occur; this occurrence is due to a phenomenon called the "Hook effect". Antigen tests such as the pregnancy test shows positive line via the formation of a sandwich immune complex that allows the positive line to be visible, in the occurrence of Hook Effect, large amounts of analyte exists in the solution which saturates the antibodies, preventing normal binding and formation of the sandwich immune complex therefore showing a weak positive line. In the case of diagnosing hyperprolactinaemia, a weak positive line can often lead to a false negative result and increase the risk of misdiagnosis of the condition or a potential pituitary adenomas. If Hook Effect is suspected in the patient diagnosis, serial dilution of the analyte until the concentration of prolactin falls within the assay's analytical measurements is suggested. Ruling out the possibilities of false negatives is important to ensure patients receive necessary care for their conditions.
Sources: en.wikipedia.org
Documented from about 1140 onwards, the comital dynasty residing in Tyrol Castle near Meran held the office of Vogts (bailiffs) in the Trent diocese. They extended their territory over much of the region and came to surpass the power of the bishops, who were nominally their feudal lords. After the deposition of the Welf Duke Henry X of Bavaria in 1138, the counts of Tyrol strengthened their independence. When Henry the Lion was again enfeoffed with the Bavarian duchy by Emperor Frederick Barbarossa at the 1154 Imperial Diet in Goslar, his possessions no longer comprised the Tyrolean lands. The counts maintained that independence under the rising Bavarian Wittelsbach dynasty. In 1210, Count Albert IV of Tyrol also took over the Vogt office in the Bishopric of Brixen, prevailing against the rivalling counts of Andechs.
Like many other insects, Drosophila typically move using a tripod gait: three of the legs swing together while the other three remain stationary. Specifically, the middle leg moves in phase with the contralateral front and hind legs. Variability around the tripod configuration exists along a continuum, with coordination strength between legs of the same tripod increasing with speed. This means that at fast speeds, the leg coordination is mostly tripod (three legs in stance), but at slower speeds, flies are more likely to have four (tetrapod) or five legs in stance (wave). These smooth transitions may help to optimize static stability. Furthermore, flies do not walk, but rather use running-like biomechanics across their whole speed range. Because flies are so small, inertial forces are negligible compared with the elastic forces of their muscles and joints or the viscous forces of the surrounding air.
The acetyl group of acetylornithine is removed by the enzyme acetylornithinase (AO) or ornithine acetyltransferase (OAT), and this yields ornithine. Then, the enzymes citrulline and argininosuccinate convert ornithine to arginine.
Sanders supports reducing military spending while pursuing more diplomacy and international cooperation. He opposed funding the Nicaraguan rebels known as the contras in the CIA's covert war against Nicaragua's leftist government. He opposed the US invasion of Iraq and has criticized a number of policies instituted during the war on terror, particularly that of mass surveillance and the USA Patriot Act. He criticized Israel's actions during the 2014 Gaza war and US involvement in the Saudi Arabian-led intervention in Yemen. On November 15, 2015, in response to the Islamic State of Iraq and the Levant (ISIL)'s attacks in Paris, he cautioned against Islamophobia and said, "We gotta be tough, not stupid" in the war against ISIL, adding that the US should continue to welcome Syrian refugees. He criticized the January 2020 drone assassination of Iranian general Qasem Soleimani, calling it a dangerous escalation of tensions that could lead to an expensive war. Sanders supports Palestinian rights and has often criticized Israel, while consistently supporting Israel's right to exist. In 2020, he called the American Israel Public Affairs Committee a platform for bigotry and said he would not attend its conference. He condemned Trump's decision to recognize Jerusalem as Israel's capital, saying, "It would dramatically undermine the prospects for an Israeli–Palestinian peace agreement, and severely, perhaps irreparably, damage the United States' ability to broker that peace." During the Gaza war, he criticized Hamas for the October 7 attacks and Israel for its bombing of Gaza.
Sources: en.wikipedia.org
United States (US) US food safety regulations have set a maximum permitted level of 20 μg/kg for aflatoxin B1, in combination with the other aflatoxins (B2, G1 and G2) in all foods, with the exception of milk which has a maximum permitted level of 0.5 μg/kg. Higher levels of 100–300 μg/kg are tolerable for some animal feeds. European Union (EU) The EU has set maximum permitted levels for aflatoxin B1 in nuts, dried fruits, cereals and spices to range from 2–12 μg/kg, while the maximum permitted level for aflatoxin B1 in infant foods is set at 0.1 μg/kg. The maximum permitted levels for aflatoxin B1 in animal feeds set by the EU range from 5–50 μg/kg and these levels are much lower than those set in the US. Joint United Nations' Food and Agriculture Organization (FAO)/World Health Organization (WHO) Expert Committee on Food Additives (JECFA) The FAO/WHO JECFA has set the maximum permitted levels of aflatoxin B1 in combination with the other aflatoxins (B2, G1 and G2) to be 15 μg/kg in raw peanuts and 10 μg/kg in processed peanuts; while the tolerance level of aflatoxin B1 alone is 5 μg/kg for dairy cattle feed.
Elevated creatine kinase Leukocytosis Low serum iron These findings overlap with neuroleptic malignant syndrome (NMS). Therefore, it is essential to make careful correlation with clinical history, medications, and physical findings.
After the collapse of the Kingdom of Yugoslavia in the April War (1941), the entire country was occupied and partitioned between Axis powers. Central territories of Serbia and the northern region of Banat were occupied by Nazi Germany, that enforced direct control over the Territory of the Military Commander in Serbia, with a puppet Government installed in Belgrade. Southern regions of Metohija and Kosovo were occupied by Fascist Italy and annexed into the Italian Albania. The region of Bačka was annexed by Hungary, while Syrmia was possessed by the Independent State of Croatia. Southeastern parts of Serbia were occupied by Bulgaria. At the beginning of the occupation, there were two resistance movements: Chetniks and Partisans. They had conflicting ideological and political programs, with Chetniks abandoning initial joint resistance efforts alongside Partisans by the end of the Uprising in Serbia, switching instead to extensive collaboration with Axis forces. Partisans advocated transformation of Yugoslavia into a federation, with Serbia becoming one of its federal units. In the autumn of 1941, first provisional institutions were established by partisans in some liberated territories, headed by the Main National Liberation Committee for Serbia. It was seated in Užice, and thus the movement became known as the Republic of Užice. However, the German offensive crushed this proto-state in December of the same year. After that, main partisan forces moved to Bosnia.
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 and a dual agonist of two incretin receptors. It is not a small molecule, and it is not structurally related to the older single-receptor peptide agonists.