The short version of Insulin-like growth factor 1 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-03 and is reviewed periodically as new material appears.
Measured responses usually involve growth hormone and insulin-like growth factor 1, known as IGF-1. Growth hormone rises in bursts and is difficult to sample reliably, while IGF-1 shifts more slowly and can be assessed from a single blood draw. Studies therefore treat IGF-1 as the more practical pharmacodynamic marker. Both are indirect, showing that the receptor was engaged rather than that the peptide reached a particular concentration. Direct exposure measurement requires an assay aimed at the molecule itself.
Published work tends to frame tesamorelin as a tool for studying the GHRH axis and as a compound with measurable effects on body composition. Reports often describe visceral adipose tissue as an endpoint, assessed by imaging rather than by inference. Analytical sections commonly describe liquid chromatography with tandem mass spectrometry to confirm identity and purity, because immunoassays may cross-react with related fragments. Where results diverge between studies, differences in assay choice, sampling timing, and population are frequent explanations offered. Whether effects persist after treatment stops remains an open question.
Because growth hormone is released in pulses, single measurements can misrepresent overall secretion. Investigators sometimes use repeated sampling or overnight profiles to capture the pattern rather than a single value. Provocative testing, in which a stimulus is given and the response is tracked over time, offers another way to characterize the axis. Each approach carries trade-offs between sensitivity, burden on the participant, and the influence of non-target variables.
Insulin-like growth factor 1 is produced largely in the liver in response to growth hormone signaling. Its concentration shifts over days rather than minutes, which makes it practical for tracking changes across a study period. Interpretation still depends on age, nutritional status, and concurrent illness, all of which independently affect the marker. Reference ranges are therefore stratified, and comparisons are usually made within an individual over time rather than against a single population threshold.
Assays for these markers differ in calibration and antibody specificity, so results from different platforms are not always interchangeable. Reported values can shift when a laboratory changes method, even without any biological change. Studies that span long periods or multiple sites often need cross-validation of assays. This methodological variability is a recognized limitation when comparing findings across published reports, and it remains a topic of ongoing standardization work.
| Property | Value | Notes |
|---|---|---|
| Primary target | GHRH receptor | Located on pituitary somatotroph cells |
| Signaling route | cAMP–protein kinase A | Gs-coupled receptor pathway |
| Downstream markers | Growth hormone and IGF-1 | Used as pharmacodynamic readouts |
| Common detection | LC-MS/MS | Separates intact peptide from fragments |
| Typical storage | 2–8 °C, protected from light | Applies to solid form before reconstitution |
质量控制项目一般包括外观、身份、纯度、含量、有关物质、水分和微生物限度。身份确认可通过肽图谱、氨基酸分析和质谱完成，纯度则用面积归一化法计算。研究级材料与药品级材料的要求不同，前者常缺少完整药典验证。不同批次间杂质谱是否影响活性，仍是一个需要具体数据回答的问题。
特沙莫瑞林的检测通常依赖反相高效液相色谱和质谱联用。反相色谱可分离肽主峰与缺失序列、氧化产物等杂质，质谱则提供精确质量以确认身份。对于复杂基质中的定量，常采用液相色谱-串联质谱，并配合固相萃取或蛋白沉淀。生物样品中的肽易降解，因此采集和处理条件会影响结果。
Studies of the compound rely on imaging and laboratory endpoints rather than on symptoms alone. Visceral adipose tissue is usually quantified by computed tomography or magnetic resonance imaging at the level of the abdomen, with waist circumference serving as a cheaper but less specific proxy. Blood work tracks insulin-like growth factor 1, fasting glucose, glycated hemoglobin, and lipid fractions. In the pivotal trials the imaging endpoint fell by roughly fifteen to twenty percent over six months, subcutaneous fat changed little, and the visceral fat returned toward baseline after treatment stopped, a pattern that shapes how clinicians discuss durability.
Whether the drug improves hard clinical outcomes is not settled. No completed trial has shown a reduction in heart attacks or strokes among treated patients, although a dedicated cardiovascular outcomes study has been discussed in the literature. Investigators have also examined hepatic fat in people with HIV and fatty liver disease, cognitive measures in small cohorts, and changes in bone density. Regulatory labeling emphasizes monitoring of insulin-like growth factor 1 because supraphysiologic levels raise questions about tissue growth, and the clinical significance of that signal remains an open question rather than a demonstrated harm.
Binding of tesamorelin to the growth hormone-releasing hormone receptor on anterior pituitary somatotrophs activates a Gs protein pathway, raises cyclic AMP, and triggers release of stored growth hormone into the bloodstream. Because the analogue resists dipeptidyl peptidase-4, its plasma residence time exceeds that of native GHRH, producing a larger and more sustained secretory signal. The released growth hormone then acts on the liver and peripheral tissues to raise insulin-like growth factor 1, which feeds back on the hypothalamus and pituitary. This axis explains both the intended effects on fat distribution and the biological markers used to track them.
In 1911, he entered St Peter's College, Adelaide, where he excelled in chemistry, physics, mathematics and history. He played various sports for the school: cricket, Australian football, tennis, and track and field athletics as a sprinter and high jumper. The cost of his education was covered by four scholarships. He served in the Senior Cadets, in which he was commissioned as a second lieutenant in August 1916. After the First World War broke out in 1914, he wished to enlist, but parental permission was required and was not forthcoming. He was head boy in his final year at school, and was ranked twelfth in the state in his final examinations. Rather than become a businessman like his father, Florey elected to follow in the footsteps of his sister Hilda, who studied medicine. He entered the University of Adelaide in March 1917, his fees paid entirely by a state scholarship. This allowed him to continue his studies after his father died from a heart attack on 15 September 1918, and the shoe company was found to be insolvent and went into liquidation. Coreega and other properties had to be sold, and in 1920, the family moved into a bungalow in Glen Osmond. Florey participated in university athletics and tennis. He was an editor of the Medical Students' Society's Review and the Adelaide University Magazine. It was through the latter that he met Mary Ethel Hayter Reed, a fellow medical student, when he asked her to contribute an article on Women in Medicine.
5-HTP has been used medically and as a supplement under the name oxitriptan in the treatment of depression and for certain other indications. As of 2025, there are no current FDA approved medications containing 5-HTP. It can be potentiated in combination with a peripherally selective aromatic L-amino acid decarboxylase (AAAD) inhibitor such as carbidopa or benserazide. These agents increase the strength and duration of oxitriptan. An investigational combination formulation is oxitriptan/carbidopa.
Antidotes are agents that can neutralise the effects of a poison or toxin. Antidotes counteract the effects of toxins in many ways, such as by blocking the absorption of the toxin, binding and neutralising the poison, opposing the toxin's end-organ function, or blocking the toxin's conversion to more hazardous metabolites. In addition to lowering the amount of free or active poison present, antidote delivery may also lessen the toxin's effects on organs through competitive inhibition, receptor blockage, or direct antagonistic interaction. The therapeutic index or ratio (TD50/ED50), which is the ratio of the toxic dosage (TD) or fatal dose (LD) to the effective dose (ED), determines the level of safety associated with a substance.
12(S)-HETE, 12(S)-HpETE, and with far less potency 12(R)-HETE reduced insulin secretion and caused apoptosis in cultured human pancreatic insulin-secreting beta cell lines and prepared pancreatic islets. TNFα, IL-1β, and IFNγ also reduced insulin secretion in cultured human pancreatic INS-1 beta cells, apparently by inducing the expression of NOX1 (NADPH oxidase 1) and thereby to the production of cell-toxic reactive oxygen species; these cytokine effects were completely dependent on 12-lipoxygenase and mimicked by 12(S)-HETE but not 12(R)-HETE. 12-lipoxygenase-knockout mice (i.e., mice genetically manipulated to remove the Alox12, i.e. 12-lipoxygenase gene, see Lipoxygenase
== History and etymology == Bismuth was one of the first 11 metals to have been discovered. The name "bismuth" dates to around 1665 and is of uncertain etymology. The name possibly comes from German Bismuth, Wismut, Wissmuth (early 16th century), perhaps related to Old High German hwiz ("white"). The Neo-Latin bisemutium (coined by Georgius Agricola, who Latinized many German mining and technical words) is from the German Wismuth, itself perhaps from weiße Masse, meaning "white mass". The element was confused in early times with tin and lead because of its resemblance to those elements. Because bismuth has been known since ancient times, no one person is credited with its discovery. The Incas used bismuth (along with the usual copper and tin) in a special bronze alloy for knives, likely intentionally. Agricola (1546) states that bismuth is a distinct metal in a family of metals including tin and lead. This was based on observation of the metals and their physical properties. Miners in the age of alchemy also gave bismuth the name tectum argenti, or "silver being made" in the sense of silver still in the process of being formed within the Earth.
Sources: en.wikipedia.org
=== Anti-Drug Abuse Act === Spurred by the media craze over the war on drugs the House of Representatives allocated $2 billion in new funding to the federal anti-drug fight in 1986. The House also authorized the use of the military in narcotics control efforts, the death penalty for some drug related crimes, and the admission of illegally obtained evidence in drug trials. In October 1986, Reagan signed the Anti-Drug Abuse Act. It supported much-harsher federal penalties than any other drug legislation in the United States ever passed, with mandatory minimum sentences for the distribution of cocaine and far more severe punishments for the distribution of crack. It outlined a 100-1 discrepancy in prison terms for crack versus powder cocaine. An individual caught with 5 g of crack cocaine would face a five-year sentence. An individual would need to be caught with 500 g of powder cocaine to carry the same sentence. Many scholars have argued that these laws were racist in nature since crack was a drug identified by the media and the public to be associated with black America and powder cocaine with white America. In addition, scholars have pointed out that data from states like New York, where mandatory minimum sentencing had originated a decade earlier, show that mandatory minimums lead to a disproportionate number of arrests of black Americans. The Act was revisited by the administration in 1988 to allow public housing authorities to evict a tenant who allowed drug-related activity to occur on or near public housing premises.
In 1933, Norway, which occupied part of Eastern Greenland, accepted a ruling of the Permanent Court of International Justice affirming Danish sovereignty over all of Greenland and renounced its claim. The 1953 Constitution of Denmark ended Greenland's status as a colony, integrating it fully into the Danish state as a regular county, as part of decolonization efforts and with the consent of the Greenland Provincial Council. In the 1979 Greenlandic home rule referendum, Denmark granted home rule to Greenland, leading to the establishment of a local government authority with responsibility for local matters, but Greenland remains part of the Kingdom of Denmark, with the central government in Copenhagen solely responsible for defence and foreign policy. As part of the Nordic region and the Kingdom of Denmark, Greenland is an associate member of the Nordic Council. Greenland is one of the Overseas Countries and Territories of the EU. Greenlanders are Danish citizens and therefore also EU citizens. In 2009, Greenland was recognised by the Kingdom of Denmark and under international law as a people entitled to external self-determination. Most political parties in Greenland favour independence from Denmark as a long-term goal, with a draft constitution for an independent Greenlandic state presented by lawmakers in 2023, but the majority does not favour severing ties with Denmark in the short term.
Macrophages can internalize antigens through receptor-mediated phagocytosis. Macrophages have a wide variety of pattern recognition receptors (PRRs) that can recognize microbe-associated molecular patterns (MAMPs) from pathogens. Many PRRs, such as toll-like receptors (TLRs), scavenger receptors (SRs), C-type lectin receptors, among others, recognize pathogens for phagocytosis. Macrophages can also recognize pathogens for phagocytosis indirectly through opsonins, which are molecules that attach to pathogens and mark them for phagocytosis. Opsonins can cause a stronger adhesion between the macrophage and pathogen during phagocytosis, hence opsonins tend to enhance macrophages' phagocytic activity. Both complement proteins and antibodies can bind to antigens and opsonize them. Macrophages have complement receptor 1 (CR1) and 3 (CR3) that recognize pathogen-bound complement proteins C3b and iC3b, respectively, as well as fragment crystallizable γ receptors (FcγRs) that recognize the fragment crystallizable (Fc) region of antigen-bound immunoglobulin G (IgG) antibodies. When phagocytosing and digesting pathogens, macrophages go through a respiratory burst where more oxygen is consumed to supply the energy required for producing reactive oxygen species (ROS) and other antimicrobial molecules that digest the consumed pathogens.
In 1H Magnetic Resonance Spectroscopy each proton can be visualized at a specific chemical shift (peak position along x-axis) depending on its chemical environment. This chemical shift is dictated by neighboring protons within the molecule. Therefore, metabolites can be characterized by their unique set of 1H chemical shifts. The metabolites that MRS probes for have known (1H) chemical shifts that have previously been identified in NMR spectra. These metabolites include:
Yavne was established in October 1948 as a transit camp for Jews from Arab countries, Iran and Europe. The first neighbourhood was established in early 1949. In the early years, the inhabitants were shopkeepers, farmers and construction workers. In 1953, the population was 1,600. In the 1960s, several enterprises moved from Tel Aviv to Yavne, establishing leather, textile, and metallurgy industries. By 1970, the population had grown to 10,100. Other Israeli villages were founded on Yibna land were Kfar HaNagid and Beit Gamliel in 1949, Ben Zakai in 1950, Kfar Aviv (originally: "Kfar HaYeor") in 1951, Tzofiyya in 1955. According to Walid Khalidi, a railroad crosses the village. The old mosque and minaret, together with a shrine can still be seen, and some of the old houses are inhabited by Jewish and Arab families. The 1980 edition of a guidebook published in Jerusalem describes Yavne as home to Israel's first atomic reactor, an image of which appeared on a 0.50 Shekel stamp. When Mayor Meir Sheetrit assumed office in 1974, the city became a low-density suburban satellite of Tel Aviv with new construction targeting middle-class families. Yavne achieved city status in 1986. By the mid-1990s, the population had risen to 25,600.
Sources: en.wikipedia.org
The effect on vascular endothelium may eventually be mediated by the arsenic-induced formation of nitric oxide. It was demonstrated that +3 As concentrations substantially lower than concentrations required for inhibition of the lysosomal protease cathepsin L in the B cell line TA3 were sufficient to trigger apoptosis in the same B cell line, while the latter could be a mechanism mediating immunosuppressive effects. Its comutagenic effects may be explained by interference with base and nucleotide excision repair, eventually through interaction with zinc finger structures. Dimethylarsinic acid, DMA(V), caused DNA single strand breaks resulting from inhibition of repair enzymes at levels of 5 to 100 mM in human epithelial type II cells. MMA(III) and DMA(III) were also shown to be directly genotoxic by effectuating scissions in supercoiled ΦX174 DNA. Increased arsenic exposure is associated with an increased frequency of chromosomal aberrations, micronuclei and sister-chromatid exchanges. An explanation for chromosomal aberrations is the sensitivity of the protein tubulin and the mitotic spindle to arsenic. Histological observations confirm effects on cellular integrity, shape and locomotion. DMA(III) can form reactive oxygen species by reaction with molecular oxygen. Resulting metabolites are the dimethylarsenic radical and the dimethylarsenic peroxyl radical. Both DMA(III) and DMA(V) were shown to release iron from horse spleen as well as from human liver ferritin if ascorbic acid was administered simultaneously.
=== Limitations and exemptions === There are limited exceptions and exemptions. For instance, the Single Convention provides exceptions to the central "exclusively to medical and scientific purposes" rule, such as for the cultivation of industrial hemp, the use of the coca leaf as a flavoring agent, and a general exemption in article 2(9) of any drug used for "other than medical and scientific purposes" (a phrase with conflicting interpretations). Countries can also join the treaties with specific national reservations.
where the precursor ion ABCD+ is selected by the first stage of mass spectrometry (MS1), dissociates into molecule AB and product ion CD+, and the latter is selected by the second stage of mass spectrometry (MS2) and detected. The precursor and product ion pair is called a SRM "transition". Consecutive reaction monitoring (CRM) is the serial application of three or more stages of mass spectrometry to SRM, represented in a simple case by
== Medical uses == Norgestrienone was used in hormonal contraception to prevent pregnancy. It has typically been used as an oral contraceptive at a dosage of 2 mg/day in combination with ethinylestradiol and 350 μ/day when used alone.
Sources: en.wikipedia.org
It acts on the growth hormone–releasing hormone receptor, a Gs-coupled receptor found on pituitary somatotroph cells. Activation raises cAMP and prompts pulsatile hormone release.
IGF-1 reflects growth hormone activity but changes slowly and can be measured from one sample. Growth hormone itself is pulsatile, which makes single measurements hard to interpret.
The receptor pathway is well described, but how individual responses vary and what governs long-term outcomes remain open questions. Reported differences across studies are often attributed to assay and population factors.
It varies slowly and reflects cumulative axis activity rather than momentary secretion. Growth hormone is released in pulses affected by sleep, stress, and meals, making single readings hard to interpret. The slower marker gives a more stable picture across a study period.