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 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
GLP-1 receptors are expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises cyclic AMP, enhances glucose-dependent insulin secretion, and suppresses glucagon release when blood glucose is high. Effects on gastric emptying and on hypothalamic appetite circuits reduce energy intake. Because insulin release remains glucose-dependent, the risk of hypoglycemia is low when the drug is used alone. The precise contribution of each pathway to body weight change in humans remains an area of active investigation.
Clinical studies of semaglutide generally measure glycated hemoglobin, fasting plasma glucose, body weight, and composite cardiovascular endpoints. The SUSTAIN program enrolled adults with type 2 diabetes, while the STEP program focused on obesity without diabetes. Administration follows a stepwise escalation schedule designed to limit gastrointestinal effects during the first weeks. Reported outcomes include mean percentage weight change, the proportion of participants reaching defined weight-loss thresholds, and rates of nausea, vomiting, and diarrhea. Long-term data on durability after treatment stops are still limited and remain a topic of ongoing research.
Semaglutide 是一种经结构修饰的胰高血糖素样肽-1 类似物，其主链与内源性 GLP-1(7-36) 约有百分之九十四的序列一致性。第 8 位丙氨酸被 α-氨基异丁酸取代，使二肽基肽酶-4 无法识别原有切割位点。第 34 位赖氨酸换为精氨酸，进一步降低酶解速率。第 26 位赖氨酸经间隔基连接一条含十八个碳的二酸脂肪链，该侧链赋予分子与血浆白蛋白结合的能力。
该分子作为 GLP-1 受体的选择性激动剂发挥作用，受体属于 B 类 G 蛋白偶联受体家族，激活后经 Gs 通路提升细胞内环腺苷酸水平。在胰腺 β 细胞，信号促进葡萄糖依赖性的胰岛素释放，血糖偏低时该作用明显减弱。在胰岛 α 细胞，胰高血糖素分泌受到抑制。中枢神经系统与胃肠道同样存在受体表达，相应信号参与食欲调节以及胃排空速率的降低。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C187H291N45O59 | Peptide backbone with a C18 fatty diacid side chain |
| Molecular weight | Approximately 4113 Da | Consistent with a 31-residue peptide plus linker |
| Appearance | White to off-white powder | Lyophilized solid; hygroscopic if left open |
| Solubility class | Sparingly soluble to soluble in water | Varies with pH and ionic strength |
| Typical analytical method | Reversed-phase HPLC with UV detection | Often paired with mass spectrometry for identity |
容器与密封系统同样参与稳定性表现。硅油涂层、胶塞材质与顶空氧含量可能改变聚集速率与氧化水平。分析结果因此需要在完整包装形式下评估，而不能仅凭原料药数据推断。法规文件通常要求同时提交批次数据与代表性容器中的稳定性趋势。
关于降解产物的免疫原性风险，文献中仍有讨论空间。体外聚集水平与临床免疫反应之间的定量关系尚未确立。多数公开研究只报告理化指标，缺少长期随访的对应数据。这一问题在生物类似物比对中尤其受到关注。
市售注射用制剂通常要求在二至八摄氏度冷藏保存，并避免光照与冻结。部分多剂量笔在首次使用后允许在不超过三十摄氏度的环境中存放有限周数，具体期限由辅料与防腐剂体系决定。反复冻融会促进肽链聚集并改变可见颗粒计数，因此应予避免。冻干粉末在干燥、避光、低温条件下更为稳定。溶液配制后宜使用低吸附容器，以减少肽类在塑料或玻璃表面的损失。
Semaglutide is a synthetic peptide that acts as an agonist at the glucagon-like peptide-1 receptor. It is a structural analogue of human GLP-1(7-37), modified to resist enzymatic degradation by dipeptidyl peptidase-4. The peptide backbone contains alpha-aminoisobutyric acid at position 8, a substitution that stabilises the helix and slows cleavage. A fatty diacid side chain attached through a linker at lysine 34 promotes binding to serum albumin, which extends the circulating half-life. These two modifications together allow less frequent administration than native GLP-1 requires.
Activation of the GLP-1 receptor couples to Gs signalling and raises intracellular cyclic AMP in pancreatic beta cells. The resulting insulin release depends on prevailing glucose concentrations, so the effect is greater when glucose is elevated. Receptor engagement also suppresses glucagon secretion and slows gastric emptying, which flattens post-meal glucose excursions. In the central nervous system, signalling in hypothalamic and brainstem regions is associated with reduced appetite and lower energy intake. Studies continue to examine effects on cardiac, renal and hepatic endpoints; whether those benefits are independent of weight change remains an open question.
Reversed-phase high-performance liquid chromatography is widely used to assess purity and to separate the parent peptide from related substances. Mass spectrometry confirms identity and can resolve modifications that differ by a few daltons. Size-exclusion chromatography detects dimers and higher aggregates, which are relevant to both stability and immunogenicity questions. Peptide mapping with enzymatic digestion locates specific modifications along the sequence. Circular dichroism provides a secondary-structure profile, although it gives limited information about local conformational changes.
Quality control for peptide material focuses on identity, purity, content and the profile of impurities. Common degradants include deamidated and oxidised forms, plus aggregates formed during storage or handling. Forced degradation studies under heat, light, acid and peroxide help define which conditions accelerate change and which analytical methods detect it. Limits for individual impurities are set by pharmacopoeial monographs or manufacturer specifications. How much a given impurity affects biological activity is often uncertain, and conclusions may depend on the assay used.
The peak of these incidents occurred in 1980, with new recruit Phil Carman making headlines for head-butting an umpire. The tribunal suspended him for sixteen weeks, and although most people thought this was a fair (or even lenient) sentence, he took his case to the Supreme Court of Victoria, gathering even more unwanted publicity for the club. Despite this, the club had recruited many talented young players in the late 1970s who emerged as club greats. Three of those young players were Simon Madden, Tim Watson and Paul Van Der Haar. Terry Daniher and his brother Neale came via a trade with South Melbourne, and Roger Merrett joined soon afterwards to form the nucleus of what would become the formidable Essendon sides of the 1980s. This raw but talented group of youngsters took Essendon to an elimination final in 1979 under Barry Davis but were again thrashed in an Elimination Final, this time at the hands of Fitzroy. Davis resigned at the end of the 1980 season after missing out on a finals appearance. One of the few highlights for Essendon supporters during this time was when Graham Moss won the 1976 Brownlow Medal; he was the only Bomber to do so in a four-decade span from 1953 to 1993. Even that was bittersweet, as he quit VFL football to move back to his native Western Australia, where Moss finished out his career as a player and coach at Claremont Football Club. In many ways, Moss's career reflects Essendon's mixed fortunes during the decade.
It is considered to be one of several antidepressants with a greater risk of hepatotoxicity. The prescribing information warns about bupropion triggering an angle-closure glaucoma attack. On the other hand, bupropion may decrease the risk of development of open angle glaucoma. Bupropion has rarely been associated with instances of Stevens–Johnson syndrome. Bupropion use by mothers in the first trimester of pregnancy is associated with a 23% increase in the odds of congenital heart defects in their children.
== Clinical application == CD38 inhibitors may be used as therapeutics for the treatment of asthma. CD38 has been used as a prognostic marker in leukemia. Daratumumab (Darzalex) which targets CD38 has been used in treating multiple myeloma. The use of Daratumumab can interfere with pre-blood transfusion tests, as CD38 is weakly expressed on the surface of erythrocytes. Thus, a screening assay for irregular antibodies against red blood cell antigens or a direct immunoglobulin test can produce false-positive results. This can be sidelined by either pretreatment of the erythrocytes with dithiothreitol (DTT) or by using an anti-CD38 antibody neutralizing agent, e.g. DaraEx.
Sources: en.wikipedia.org
A record in the form of proof of baptisms shall be made, containing the time and hour of birth. An extract from this register may be used to prove the age of majority or minority and will serve as full legal evidence for this purpose. Before this legal requirement, fifteen Parisian parishes already kept baptismal registers, three kept marriage registers, and one kept burial registers. Presided over by Pope Paul III from 1545 to 1563, the Council of Trent also required priests to keep a register of baptisms performed in their parish. The names of godparents had to be included to prevent marriages between people linked by spiritual kinship (e.g., a godfather and his goddaughter could not marry). The council also mandated that marriages, freely contracted before a priest and two or three witnesses, be preceded by the publication of banns and recorded in a designated register. It also advocated for the union of children without requiring parental consent. In May 1579, the Ordinance of Blois extended the obligation to keep marriage and burial registers throughout France. The Ordinance of Saint-Germain-en-Laye of April 1667, known as the "Code Louis," required these registers to be kept in duplicate: the first copy (the minute) remained in the parish, while the duplicate (the grosse) was deposited at the court registry. In Paris, the Châtelet registry preserved the second copy, with the oldest dating back to 1668. By 1790, the capital had around fifty parishes.
The principal physiological function of glyoxalase I is the detoxification of methylglyoxal, a reactive 2-oxoaldehyde that is cytostatic at low concentrations and cytotoxic at millimolar concentrations. Methylglyoxal is a by-product of normal biochemistry that is a carcinogen, a mutagen and can chemically damage several components of the cell, such as proteins and nucleic acids. Methylglyoxal is formed spontaneously from dihydroxyacetone phosphate, enzymatically by triosephosphate isomerase and methylglyoxal synthase, as also in the catabolism of threonine. To minimize the amount of toxic methylglyoxal and other reactive 2-oxoaldehydes, the glyoxalase system has evolved. The methylglyoxal reacts spontaneously with reduced glutathione (or its equivalent, trypanothione),) forming a hemithioacetal. The glyoxalase system converts such compounds into D-lactate and restored the glutathione. In this conversion, the two carbonyl carbons of the 2-oxoaldehyde are oxidized and reduced, respectively, the aldehyde being oxidized to a carboxylic acid and the acetal group being reduced to an alcohol. The glyoxalase system evolved very early in life's history and is found nearly universally through life-forms. The glyoaxalase system consists of two enzymes, glyoxalase I and glyoxalase II. The former enzyme, described here, rearranges the hemithioacetal formed naturally by the attack of glutathione on methylglyoxal into the product. Glyoxalase II hydrolyzes the product to re-form the glutathione and produce D-lactate.
This complication may manifest as systemic infections, such as sepsis, or as localized outbreaks, such as Herpes simplex, shingles, or other members of the Herpesviridea. The risk of illness and death can be reduced by taking common antibiotics such as quinolones or trimethoprim/sulfamethoxazole before any fever or sign of infection appears. Quinolones show effective prophylaxis mainly with hematological cancer. However, in general, for every five people who are immunosuppressed following chemotherapy who take an antibiotic, one fever can be prevented; for every 34 who take an antibiotic, one death can be prevented. Sometimes, chemotherapy treatments are postponed because the immune system is suppressed to a critically low level. In Japan, the government has approved the use of some medicinal mushrooms like Trametes versicolor, to counteract depression of the immune system in people undergoing chemotherapy. Trilaciclib is an inhibitor of cyclin-dependent kinase 4/6 approved for the prevention of myelosuppression caused by chemotherapy. The drug is given before chemotherapy to protect bone marrow function.
Sources: en.wikipedia.org
In New Zealand, it was applied to the kawakawa (Piper excelsum), which is endemic to New Zealand and nearby Norfolk Island and Lord Howe Island. It was exploited by the Māori based on previous knowledge of the kava, as the latter could not survive in the colder climates of New Zealand. The Māori name for the plant, kawakawa, is derived from the same etymon as kava, but reduplicated. It is a sacred tree among the Māori people. It is seen as a symbol of death, corresponding to the rangiora (Brachyglottis repanda), which is the symbol of life. However, kawakawa has no psychoactive properties. Its connection to kava is linked to its similarity in appearance and bitter taste. Other names for kava include ʻawa (Hawaii), ʻava (Samoa), yaqona or yagona (Fiji), sakau (Pohnpei), seka (Kosrae), and malok or malogu (parts of Vanuatu).
The early republican government was a military dictatorship, with the army dominating affairs both in Rio de Janeiro and in the states. Freedom of the press disappeared and elections were controlled by those in power. Not until 1894, following an economic crisis and a military one, did civilians take power, remaining there until October 1930. In this first republican period, Brazil maintained a relative balance characterized by a success in resolving border disputes with neighboring countries, only broken by the Acre War (1899–1902) and its involvement in World War I (1914–1918), followed by a failed attempt to exert a prominent role in the League of Nations; Internally, from the crisis of Encilhamento and the Navy Revolts, a prolonged cycle of financial, political and social instability began until the 1920s, keeping the country besieged by various rebellions, both civilian and military. Little by little, a cycle of general instability sparked by these crises undermined the regime to such an extent that in the wake of the murder of his running mate, the defeated opposition presidential candidate Getúlio Vargas, supported by most of the military, successfully led the Revolution of 1930. Vargas and the military were supposed to assume power temporarily, but instead closed down Congress, extinguished the Constitution, ruled with emergency powers and replaced the states' governors with his own supporters. In the 1930s, three attempts to remove Vargas and his supporters from power failed. The first was the Constitutionalist Revolution in 1932, led by São Paulo's oligarchy.
=== Computing === .MSI, the filename extension of Windows Installer packages Medium scale integration, a generation of integrated circuit chips which contain hundreds of transistors Message Signaled Interrupts, a PCI 2.2 interrupt-mechanism MSI protocol, a basic cache-coherence protocol used in multiprocessor systems
Sources: en.wikipedia.org
It is given either as a once-weekly subcutaneous injection or as an oral tablet taken once daily. The two forms use different absorption strategies, so they are not interchangeable on a milligram-for-milligram basis.
Structural modifications, including a fatty acid side chain and non-natural amino acid substitutions, slow enzymatic breakdown and promote albumin binding. These changes support once-weekly dosing rather than twice-daily administration.
The pathways involving insulin, glucagon, gastric emptying, and appetite signaling are well described. How much each pathway contributes to weight reduction in a given person is not fully established.
差别集中在三处：第 8 位残基被非天然氨基酸取代，第 34 位换成精氨酸，第 26 位增加一条脂肪酸侧链。前两处改动降低酶解速率，侧链则通过白蛋白结合延长循环时间。综合结果是半衰期从约两分钟延长到约一周。