垂体受体 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 2025-09-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
作用位置在垂体前叶。tesamorelin 与 GHRH 受体结合后激活腺苷酸环化酶，升高细胞内 cAMP，再经蛋白激酶 A 通路促进生长激素的合成与释放。由于它作用于内源调控节点，生长激素仍以脉冲方式分泌，而不是被持续抬升到固定水平。生长激素随后在肝脏等组织诱导胰岛素样生长因子 1 产生，构成完整的生长激素轴响应。
研究背景集中在特定人群的体成分改变，尤其是与脂肪分布异常相关的内脏脂肪堆积。不同地区对它的监管状态与获批适应症并不一致，部分市场仅限特定诊断人群使用。在一般人群中的长期效应、与其他激素的相互作用以及停药后的维持情况仍属开放问题，现有数据不足以给出普遍结论。
Clinical study of tesamorelin has centered on adults with HIV-associated lipodystrophy, a condition in which abdominal fat accumulates while peripheral fat is lost. In controlled trials, treated participants showed reductions in visceral adipose tissue measured by imaging, alongside modest shifts in some lipid values. Effects on subcutaneous fat were smaller and less consistent across studies. Whether these changes translate into fewer cardiovascular events remains an open question, because the trials were not designed or powered to answer it.
Tesamorelin is a synthetic peptide that acts as an analog of growth hormone-releasing hormone, a natural hypothalamic signal. Its sequence corresponds to the forty-four amino acid form of the human hormone, with a small acyl group attached near the amino terminus. That modification slows enzymatic breakdown and extends the time the peptide remains active in circulation. The compound was developed as a pharmacological way to raise endogenous growth hormone output rather than supplying the hormone directly.
After injection, the peptide binds receptors on somatotroph cells in the anterior pituitary. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone into the bloodstream. Because the compound works through the body's own regulatory system, growth hormone pulses retain much of their normal feedback control. Repeated administration also raises insulin-like growth factor 1, a hormone produced mainly in the liver. Investigators treat that rise as a marker that the pituitary axis has been engaged.
| 性质 | 取值 | 备注 |
|---|---|---|
| 分子类型 | 合成四十四肽 | GHRH 类似物 |
| N 端修饰 | 反式-3-己烯酰基 | 延缓酶切 |
| 分子量 | 约 5135 Da | 依序列与修饰 |
| 受体靶点 | 垂体 GHRH 受体 | 经 cAMP 通路 |
| 常见同义名 | GHRH(1-44) 类似物 | 文献通用称法 |
Clinical interest in tesamorelin arose from the need to address visceral adiposity in people living with HIV. Antiretroviral therapy improved survival but was associated in some patients with central fat accumulation, altered lipid profiles, and metabolic complications. This condition, often called HIV-associated lipodystrophy, involves excess visceral adipose tissue that is difficult to manage through diet and exercise alone. Investigators evaluated tesamorelin because GHRH analogs can stimulate growth hormone secretion and influence fat distribution without direct liposuction or invasive procedures.
A Phase 3 program led to regulatory approval in the United States in 2010 for reduction of excess visceral abdominal fat in adults with HIV and lipodystrophy. Subsequent studies examined effects on liver fat, muscle area, and metabolic markers, with mixed findings for some endpoints. Long-term cardiovascular outcomes and effects on mortality remain uncertain because most trials were relatively short and focused on imaging-based fat measurements. Use in populations without HIV has been studied experimentally but is not part of the approved indication.
The three substrates of this enzyme are taxusin, oxygen, and a proton. It uses a reduced nicotinamide adenine dinucleotide (NADH) cofactor bound to a heme in cytochrome P450 to give 7β-hydroxytaxusin and water as products. The enzyme is found in the yew tree Taxus cuspidata and is part of the pathway for the biosynthesis of taxol.
== Further reading == Gunten, Hans R. von (1995). "Radioactivity: A Tool to Explore the Past" (PDF). Radiochimica Acta. 70–71 (s1): 305–413. doi:10.1524/ract.1995.7071.special-issue.305. S2CID 100441969. Magill, Joseph; Galy, Jean (2005). "Archaeology and Dating". Radioactivity Radionuclides Radiation. Springer Berlin Heidelberg. pp. 105–115. Bibcode:2005rrr..book.....M. doi:10.1007/3-540-26881-2_6. ISBN 978-3-540-26881-9. Allègre, Claude J (4 December 2008). Isotope Geology. Cambridge University Press. ISBN 978-0-521-86228-8. McSween, Harry Y; Richardson, Steven Mcafee; Uhle, Maria E; Uhle, Professor Maria (2003). Geochemistry: Pathways and Processes (2 ed.). Columbia University Press. ISBN 978-0-231-12440-9. Harry y. Mcsween, Jr; Huss, Gary R (29 April 2010). Cosmochemistry. Cambridge University Press. ISBN 978-0-521-87862-3. Rollinson, Hugh R. (1993). Using geochemical data: evaluation, presentation, interpretation. Harlow: Longman. ISBN 0-582-06701-4. OCLC 27937350.
The secretin-cholecystokinin test (aka Secretin-CCK test, Secretin-Pancreozymin test) is a combination of the secretin test and the cholecystokinin test and is used to assess the function of both the pancreas and gall bladder.
3 January 1919: to avoid anarchy in Greater Poland, the Commission of the NRL decides to take over control of the spontaneous uprising but also decides that the decision should be kept secret. 4 January 1919: The Commission of the NRL decrees a new president of the Province of Poznań, Wojciech Trąmpczyński. German authorities call for boycotting him. 5 January 1919: Czarnków, Jutrosin, Kruszwica, Nakło, Nowy Tomyśl, Miejska Górka, Rawicz, Strzelno and Wolsztyn are captured by the Poles. 6 January 1919 The Poles capture Ławica Airport, Poznań, with all aircraft undamaged. Fighting near Czersk and Kościerzyna in Pomerania. Inowrocław captured. 7 January 1919 The Poles divide captured lands into seven Military Districts (Okręg Wojskowy). The Germans recapture Chodzież and Czarnków. 8 January 1919 The Commission of the NRL takes all civil and military authority without declaring territorial range of that power. It also promotes General Józef Dowbor-Muśnicki to commander-in-chief of the uprising forces. The Poles recapture Chodzież Battle of Chodzież and Czarnków. They also win the Battle of Ślesin and capture Sieraków. 9 January 1919 The NRL officially announces that it takes control over Greater Poland. Beginning of polonisation of administration, most former anti-Polish officials being fired. In powiats, German landrats are subordinated to Polish starostas, which take all their power. Poles lose Nakło. Polish airmen bomb military airfield in Frankfurt (Oder) 10 January 1919: fights on southern front near Kąkolewo, Leszno and Rydzyna. Poles capture Sarnowa.
== Prognosis == An elevation in serum bilirubin level of more than 2 times ULN with associated transaminase rise indicates severe hepatotoxicity and is likely to lead to mortality in 10% to 15% of patients, especially if the offending drug is not stopped (Hy's Law). This is because it requires significant damage to the liver to impair bilirubin excretion, hence minor impairment (in the absence of biliary obstruction or Gilbert syndrome) would not lead to jaundice. Other poor predictors of outcome are old age, female sex, high AST.
Sources: en.wikipedia.org
Audience tastes were fairly eclectic during the 20th century, but several trends did emerge. During the silent era, films with war themes were popular with audiences, with The Birth of a Nation (American Civil War), The Four Horsemen of the Apocalypse, The Big Parade and Wings (all World War I) becoming the most successful films in their respective years of release, with the trend coming to an end with All Quiet on the Western Front in 1930. With the advent of sound in 1927, the musical—the genre best placed to showcase the new technology—took over as the most popular type of film with audiences, with 1928 and 1929 both being topped by musical films. The genre continued to perform strongly in the 1930s, but the outbreak of World War II saw war-themed films dominate again during this period, starting with Gone with the Wind (American Civil War) in 1939, and finishing with The Best Years of Our Lives (World War II) in 1946. Samson and Delilah (1949) saw the beginning of a trend of increasingly expensive historical dramas set during Ancient Rome/biblical times throughout the 1950s as cinema competed with television for audiences, with Quo Vadis, The Robe, The Ten Commandments, Ben-Hur and Spartacus all becoming the highest-grossing film of the year during initial release, before the genre started to wane after several high-profile failures. The success of White Christmas and South Pacific in the 1950s foreshadowed the comeback of the musical in the 1960s with West Side Story, Mary Poppins, My Fair Lady, The Sound of Music and Funny Girl all among the top films of the decade.
== Career == After his studies at Leipzig had ended, he began a year of work at the Moabit Hospital in Berlin as the resident pathologist. During this time, he began his research and studies on the issue of atherosclerosis. His first published works, dated during this period were in on the development of atherosclerosis in experimental animals when administered cholesterol. He also spent time working in the laboratory of Peter Rona at the Berlin Municipal Hospital. In 1926, Schoenheimer was invited by Ludwig Aschoff to join the faculty at the University of Freiburg. There he worked as an assistant professor. The investigation of pathological material was part of his work duties. During this time, he also researched atherosclerosis and the role of dietary cholesterol in its development. He became the active in 1927, and then the titular, head of his division in 1931. In 1930, until 1931, Schoenheimer was in the United States as the Douglas Smith Fellow at the University of Chicago. During this time Schoenheimer came into contact with the Josiah Macy Jr Foundation. Later in 1931, The Macy Foundation, with Ludwig Kast as its president, started supporting Schoenheimer in his atherosclerosis studies. Following his fellowship, he returned to the University of Freiburg, taking the position of head of the Pathological Chemistry department.
=== Historic regulations === Because it was recognized that coffee contained some compound that acted as a stimulant, first coffee and later also caffeine has sometimes been subject to regulation. For example, in the 16th century Islamists in Mecca and in the Ottoman Empire made coffee illegal for some classes. Charles II of England tried to ban it in 1676, Frederick II of Prussia banned it in 1777, and coffee was banned in Sweden at various times between 1756 and 1823. In 1911, caffeine became the focus of one of the earliest documented health scares, when the US government seized 40 barrels and 20 kegs of Coca-Cola syrup in Chattanooga, Tennessee, alleging the caffeine in its drink was "injurious to health". Although the Supreme Court later ruled in favor of Coca-Cola in United States v. Forty Barrels and Twenty Kegs of Coca-Cola, two bills were introduced to the US House of Representatives in 1912 to amend the Pure Food and Drug Act, adding caffeine to the list of "habit-forming" and "deleterious" substances, which must be listed on a product's label.
==== Infections ==== Some observational studies have detected significant associations between benzodiazepines and respiratory infections such as pneumonia where others have not. A large meta-analysis of pre-marketing randomized controlled trials on the pharmacologically related Z-Drugs suggest a small increase in infection risk as well. An immunodeficiency effect from the action of benzodiazepines on GABA-A receptors has been postulated from animal studies.
Sources: en.wikipedia.org
Spider angiomata or spider nevi happen when there is dilatation of vasculature beneath the skin surface. There is a central, red spot with reddish extensions that radiate outward. This creates a visual effect that resembles a spider. It occurs in about one-third of cases. The likely cause is an increase in estrogen. Cirrhosis causes a rise in estrogen due to increased conversion of androgens into estrogen. Palmar erythema, a reddening of the palm below the thumb and little finger, is seen in about 23% of cirrhosis cases, and results from increased circulating estrogen levels. Gynecomastia, or the increase of breast size in men, is caused by increased estradiol (a potent type of estrogen). This can occur in up to two-thirds of cases. Hypogonadism signifies a decreased functionality of the gonads. This can result in impotence, infertility, loss of sexual drive, and testicular atrophy. A swollen scrotum may also be evident. Liver size can be enlarged, normal, or shrunken in people with cirrhosis. As the disease progresses, the liver will typically shrink due to the result of scarring. Jaundice is the yellowing of the skin. It can additionally cause yellowing of mucous membranes notably of the white of the eyes. This phenomenon is due to increased levels of bilirubin, which may also cause the urine to be dark-colored.
== Preparation == The compound is prepared by reacting 4-tert-butylbenzoic methyl ester (from 4-tert-butylbenzoic acid by esterification with methanol) with 4-methoxyacetophenone in toluene in the presence of sodium amide via Claisen condensation.
In biology, sulfation is typically effected by sulfotransferases, which catalyze the transfer of the equivalent of sulfur trioxide to substrate alcohols and phenols, converting the latter to sulfate esters. The source of the SO3 group is usually 3'-phosphoadenosine-5'-phosphosulfate (PAPS). When the substrate is an amine, the result is a sulfamate. Sulfation is one of the principal routes for post-translational modification of proteins. Sulfation is involved in a variety of biological processes, including detoxification, hormone regulation, molecular recognition, cell signaling, and viral entry into cells. It is among the reactions in phase II drug metabolism, frequently effective in rendering a xenobiotic less active from a pharmacological and toxicological standpoint, but sometimes playing a role in the activation of xenobiotics (e.g. aromatic amines, methyl-substituted polycyclic aromatic hydrocarbons). Sulfate is part of sulfolipids, such as sulfatides, which constitute 20% of the galactolipids in myelin. Another example of biological sulfation is in the synthesis of sulfonated glycosaminoglycans, such as heparin, heparan sulfate, chondroitin sulfate, and dermatan sulfate. Sulfation is also a possible posttranslational modification of proteins.
Sources: en.wikipedia.org
tesamorelin 属 GHRH 类似物，作用于垂体受体以促进内源生长激素释放；生长激素本身是直接补充的外源激素。两者在给药逻辑、作用位点和反馈调控路径上并不相同。
作为多肽，它难以通过胃肠道吸收，通常需要注射给药。口服会因消化酶降解而失去活性，因此文献中讨论的都是注射途径。
公开研究多集中在内脏脂肪、体成分分布以及与生长激素轴相关的代谢指标。长期安全性和在普通人群中的适用性尚缺乏一致结论。
It is a laboratory-made peptide that mimics growth hormone-releasing hormone. It prompts the pituitary gland to release growth hormone and has been studied mainly in adults with HIV-associated lipodystrophy.