If you have been reading about somatotroph and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-03-05. Numbers and descriptions here follow the published literature rather than marketing material.
Signaling begins at the GHRH receptor, a class B G protein-coupled receptor displayed on somatotroph cells of the anterior pituitary. Receptor occupancy activates Gs proteins, which raise adenylyl cyclase activity and intracellular cyclic AMP, in turn driving protein kinase A dependent pathways. The downstream output is synthesis and pulsatile secretion of growth hormone into the bloodstream. Hepatic tissue and peripheral sites respond by increasing insulin-like growth factor 1 production. Somatostatin and IGF-1 itself supply negative feedback that caps the size and duration of each secretory burst.
Metabolic interest in this compound centers on fat distribution rather than on hormone levels alone. Imaging trials in adults with excess abdominal fat report reductions in visceral adipose tissue, while subcutaneous depots change comparatively little. Growth hormone and IGF-1 are presumed to carry the effect, but the separate contribution of each is not firmly established. Whether these changes persist after treatment stops, and whether they alter longer-term health outcomes, remain open questions that published work does not answer consistently.
Tesamorelin is a synthetic peptide of forty-four amino acids whose sequence reproduces human growth hormone-releasing hormone. Its distinguishing feature sits at the amino terminus, where a trans-3-hexenoyl group replaces the free amine. That acylation slows cleavage by dipeptidyl peptidase IV, an enzyme that otherwise removes the first two residues and inactivates the natural hormone quickly. The modified peptide therefore persists longer in circulation while keeping the same receptor target. It is handled as a lyophilized solid and dissolved shortly before use.
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.
Tesamorelin is a synthetic analog of growth hormone-releasing hormone, a peptide hormone produced by the hypothalamus. The molecule retains the 44-amino-acid sequence of human GHRH and carries a trans-3-hexenoyl modification at its N-terminus. This modification increases resistance to enzymatic degradation and extends the peptide's functional stability relative to native GHRH. The compound is supplied as a lyophilized powder for reconstitution and subcutaneous administration in clinical settings. Its development code was TH9507, and it belongs to the GHRH analog class. It is not a growth hormone product; instead, it acts upstream to stimulate endogenous growth hormone release.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic 44-residue peptide | GHRH analog backbone |
| Approximate molecular mass | 5136 Da | Varies with counterion and hydration state |
| N-terminal group | trans-3-hexenoyl | Increases resistance to dipeptidyl peptidase IV |
| Primary receptor | GHRH receptor (GHRHR) | Class B G protein-coupled receptor on somatotrophs |
| Principal mediator | IGF-1 | Rises indirectly after growth hormone release |
The hexenoyl cap slows the enzyme step that trims the amino terminus of native GHRH, the same step that shortens its active lifetime in circulation. As a result, the modified peptide persists longer in plasma than the unmodified hormone in side-by-side comparison. Receptor activity stays broadly comparable, because the added group sits away from the residues that contact the binding site. This combination, preserved receptor activity with reduced degradation, explains why the analog was developed instead of the native sequence.
Several compounds share the GHRH framework, including sermorelin, the shorter 1-29 fragment, and other analogs built on the full 1-44 chain. Naming follows a common convention: a stem that identifies the peptide plus a suffix marking analog status. Reports may describe tesamorelin by its sequence fragment, as a GHRH(1-44) analog, or by its amino-terminal modification. Indexing the compound therefore requires searching all of these forms, since some older literature predates the current international nonproprietary name.
Several related peptides act on the same receptor, including sermorelin, a shorter GHRH fragment, and modified analogs such as CJC-1295 and modified GRF(1-29) that are common in research settings rather than approved products. Tesamorelin differs from growth hormone itself in that it acts upstream, prompting the pituitary to release the hormone through physiological signaling rather than supplying it directly. Terminology in the literature distinguishes GHRH analogs, growth hormone secretagogues, and recombinant growth hormone, although popular discussion often blurs these categories together. Precise naming matters when comparing study results.
Tesamorelin is a synthetic peptide of 44 amino acids that reproduces the sequence of human growth hormone-releasing hormone (GHRH) and carries a trans-3-hexenoyl group on its N-terminal tyrosine. That small fatty-acid modification blocks cleavage by dipeptidyl peptidase-4, the enzyme that rapidly degrades native GHRH in plasma. The result is a molecule with a longer circulating half-life than the natural hormone while retaining the same receptor target. It is supplied as a lyophilized powder for reconstitution and belongs to the broader class of GHRH analogs studied for effects on pituitary growth hormone secretion.
The native hormone is produced in the hypothalamus and acts on the anterior pituitary. Binding of GHRH to its receptor stimulates synthesis and release of growth hormone into circulation. Because the analogue retains the receptor-binding region of the parent sequence, it engages the same receptor and triggers the same downstream signaling. The result is increased growth hormone secretion from pituitary cells, which in turn influences hepatic production of insulin-like growth factor 1. This axis is the basis for the compound's measured biological effects.
Interest in this peptide developed because native GHRH has a short circulating lifetime. The N-terminal modification slows cleavage by dipeptidyl peptidase IV, an enzyme that removes the first two residues of many peptides and terminates their activity. Slower degradation means a longer window of receptor stimulation per administration. This design logic parallels other modified peptide hormones, where a small chemical change at a vulnerable site yields a more durable molecule without altering the core mechanism of action.
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.
==== PEG treatment ==== The purpose of the polyethylene glycol is to remove water from the wood while simultaneously bulking the deteriorated wood cells. PEG is applied to the surface, either by spraying or immersing the object in a solution of PEG in water. Over the course of the treatment, PEG is slowly increased in concentration, pushing out the excess water, coating the interior walls of the wood cells with PEG, which, depending on the molecular weight selected, will provide support once the artifact is dried. PEG compounds with different molecular weights may be used depending on the wood type, level of deterioration, and scope of project. The PEG treatment is often paired with vacuum freeze-drying, as the eutectic point of most PEG solutions is below the freezing point of water. This allows the "free" waterlogging water to sublimate in the process of freeze-drying, which minimizes damage to the wood by preventing ice from forming within the cells and expanding, causing more shrinking and warping. Some artifacts are too large to fit in a commercially available freeze-drier (see the treatment for Vasa or Mary Rose or the Bremen cog).
=== Drugs that induce a type 1 diabetes like syndrome === Some medicines can reduce insulin production or damage β cells, resulting in a disease that resembles type 1 diabetes. The antiviral drug didanosine triggers pancreas inflammation in 5 to 10% of those who take it, sometimes causing lasting β-cell damage. Similarly, up to 5% of those who take the anti-protozoal drug pentamidine experience β-cell destruction and diabetes. Several other drugs cause diabetes by reversibly reducing insulin secretion, namely statins (which may also damage β cells), the post-transplant immunosuppressants cyclosporin A and tacrolimus, the leukemia drug L-asparaginase, and the antibiotic gatifloxicin.
In addition to its role as a natural hormone, estradiol is used as a medication, for instance in menopausal hormone therapy, and feminizing hormone therapy for transgender women and some genderqueer individuals; for information on estradiol as a medication, see the estradiol (medication) article.
==== 1960s–1970s ==== During the 1960s and 1970s, a number of new synthetic hallucinogens were introduced, with a notable example being the sale of highly potent tablets of DOM in San Francisco in 1967. There was little scope to prosecute people over drug analogues at this time, with new compounds instead being added to the controlled drug schedules one by one as they became a problem. One significant court case from this period was in 1973, when Tim Scully and Nicholas Sand were prosecuted for making the acetyl amide of LSD, known as ALD-52. At this time ALD-52 was not a controlled drug, but they were convicted on the grounds that in order to make ALD-52, they would have had to be in possession of LSD, which was illegal. The late 1960s also saw the introduction of various analogues of phencyclidine (PCP) to the illicit market, with Eticyclidine (PCE) first being detected in 1969.
===== Carbon fixation and G3P synthesis ===== The Calvin cycle starts by using the enzyme RuBisCO to fix CO2 into five-carbon Ribulose bisphosphate (RuBP) molecules. The result is unstable six-carbon molecules that immediately break down into three-carbon molecules called 3-phosphoglyceric acid, or 3-PGA. The ATP and NADPH made in the light reactions is used to convert the 3-PGA into glyceraldehyde-3-phosphate, or G3P sugar molecules. Most of the G3P molecules are recycled back into RuBP using energy from more ATP, but one out of every six produced leaves the cycle—the end product of the dark reactions.
Sources: en.wikipedia.org
Cream can be skimmed from whey. Whey cream is saltier, tangier, and "cheesier" than ("sweet") cream skimmed from milk, and can be used to make whey butter. Due to the low fat content of whey, the yield is low, with typically two to five parts of butter manufactured from the whey of 1,000 parts milk. Whey cream and butter are suitable for making butter-flavoured food, as they have a stronger flavour of their own. They are also cheaper to manufacture than sweet cream and butter.
Molecular dynamics (MD) is a computer simulation method for analyzing the physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a fixed period of time, giving a view of the dynamic "evolution" of the system. In the most common version, the trajectories of atoms and molecules are determined by numerically solving Newton's equations of motion for a system of interacting particles, where forces between the particles and their potential energies are often calculated using interatomic potentials or molecular mechanical force fields. MD simulations are widely applied in chemical physics, materials science, and biophysics. Because molecular systems typically consist of a vast number of particles, it is impossible to determine the properties of such complex systems analytically; MD simulation circumvents this problem by using numerical methods. However, long MD simulations are mathematically ill-conditioned, generating cumulative errors in numerical integration that can be minimized with proper selection of algorithms and parameters, but not eliminated. For systems that obey the ergodic hypothesis, the evolution of one molecular dynamics simulation may be used to determine the macroscopic thermodynamic properties of the system: the time averages of an ergodic system correspond to microcanonical ensemble averages. MD has also been termed "statistical mechanics by numbers" and "Laplace's vision of Newtonian mechanics" of predicting the future by animating nature's forces and allowing insight into molecular motion on an atomic scale.
=== Gm–Gu === Leopold Gmelin (1788–1853), German chemist who discovered potassium ferricyanide; author of Handbook of Chemistry, which is still used Theodore Nicolas Gobley (1811–1874), French chemist, pioneer in brain tissues analysis, discoverer of lecithin Sulamith Goldhaber (1923–1965), Austrian-American chemist, high-energy physicist, and molecular spectroscopist Victor Goldschmidt (1888–1947), Norwegian mineralogist considered to be one of the founders of modern geochemistry Moses Gomberg (1866–1947), Russian-American chemist, known for pioneering work in radical chemistry Mary L. Good (1931–2019), American inorganic chemist who studied catalysis by ruthenium David van Goorle also called Gorlaeus (1591–1612), Dutch chemist, one of the first modern atomists, who thought that all bodies are made up of atoms Loney Gordon (1915–1999), American chemist who assisted in creating the pertussis vaccine Carl Gräbe (1841–1927), German chemist who synthesized the dye alizarin Thomas Graham (1805–1869), Scottish chemist known for pioneering work on dialysis and diffusion of gases Harry B. Gray (born 1935), American chemist known for the kinetics of long-range electron-transfer reactions in metalloproteins; 2004 Wolf Prize in Chemistry Martha Greenblatt (born 1941), American solid state inorganic chemist, 2003 American Chemical Society's Garvan-Olin Medal Bettye Washington Greene (1935–1995), American industrial chemist who studied colloid and latex chemistry, including interactions between latex and paper Sandra C.
== Mechanism of action == Brincidofovir is a prodrug that is composed of cidofovir conjugated with a lipid molecule. The lipid aspect of the molecule takes on the action of endogenous lysophosphatidyl choline, which then is able to enter cells in the body which are infected with smallpox. Once the infected cell takes in the drug, the drug cleaves to generate cidofovir. Cidofovir is then consequently phosphorylated to yield cidofovir diphosphate, which is the active drug. Cidofovir diphosphate inhibits the variola virus' DNA polymerase-mediated DNA synthesis. The drug acts as an acyclic nucleotide and incorporates itself into the viral DNA chain, which then stops viral DNA synthesis.
Sources: en.wikipedia.org
The amino acid sequence matches human growth hormone-releasing hormone, but the amino terminus carries a trans-3-hexenoyl group instead of a free amine. That single structural change chiefly affects enzymatic stability rather than receptor selectivity.
Growth hormone released from the pituitary stimulates IGF-1 production in the liver and other tissues, so circulating IGF-1 generally rises during exposure. The size of the rise varies between individuals and depends on baseline hormonal status and other concurrent factors.
Reported imaging studies focus on visceral adipose tissue, where reductions are more consistently observed across trials. Subcutaneous depots show smaller and less reproducible changes, so the two compartments should not be treated as equivalent.
It is a synthetic peptide analog of human growth hormone-releasing hormone. It is used clinically to reduce excess visceral abdominal fat in adults with HIV-associated lipodystrophy. It works by stimulating pituitary growth hormone release.