A practical reference on somatotroph: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-22 and is reviewed periodically as new material appears.
Tesamorelin is a synthetic peptide that belongs to the growth hormone-releasing hormone family and contains the same forty-four amino acid sequence as endogenous GHRH, extended at the amino terminus by a trans-3-hexenoyl group. That small fatty acid modification protects the peptide from rapid cleavage by dipeptidyl peptidase-4, the enzyme that shortens the half-life of native GHRH to only a few minutes. Chemically the compound is produced by solid-phase peptide synthesis, purified by chromatography, and supplied as a sterile lyophilized powder for reconstitution.
Regulatory approval in the United States came in 2010, when the Food and Drug Administration cleared the peptide for the reduction of excess abdominal fat in adults with HIV infection and associated lipodystrophy. The decision rested mainly on two randomized phase 3 trials that enrolled roughly eight hundred patients and ran for twenty-six weeks. Participants receiving active drug showed substantially greater declines in visceral adipose tissue than those receiving placebo, while total body weight changed comparatively little. A reformulated presentation was later approved, and the product has remained a niche therapy rather than a general weight-loss agent.
Measuring the effect of a growth hormone-releasing hormone analogue requires markers that reflect pituitary output rather than the peptide itself. The two most frequently used are growth hormone and insulin-like growth factor 1. Growth hormone fluctuates sharply across the day and responds to sleep, stress, and meals, so isolated readings can be difficult to interpret. Insulin-like growth factor 1 changes more slowly and is often treated as the more stable integrated marker of axis activity.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide class | Synthetic GHRH analogue | 44 residues; N-terminal trans-3-hexenoyl group |
| First approval year | 2010 | United States; HIV-associated abdominal fat accumulation |
| Administration route | Subcutaneous injection | Abdominal site; clinician-administered or self-injected |
| Common synonyms | TH9507; tesamorelin acetate | Development code and acetate salt form |
| Originator | Canadian biotechnology firm | Original developer and regulatory sponsor |
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.
Stimulated growth hormone release leads to hepatic production of insulin-like growth factor 1, a key mediator of many growth hormone effects. In clinical studies, tesamorelin increased IGF-1 levels in a dose-dependent manner, although the response varies among individuals. The drug's effect on visceral fat is thought to involve growth hormone-mediated lipolysis and altered adipocyte metabolism. Muscle mass and lean body mass have also been assessed as secondary outcomes, but changes are generally smaller and less consistent than fat reductions.
Pharmacodynamic studies show that tesamorelin reduces visceral adipose tissue more than subcutaneous adipose tissue in the studied population. This selectivity may relate to differences in blood flow and hormone sensitivity between fat depots. Effects on glucose metabolism and insulin sensitivity have been investigated, with some trials reporting modest changes and others showing stability. The precise relationship between growth hormone exposure, IGF-1 levels, and visceral fat loss remains an active area of analysis.
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.
Tesamorelin is a synthetic peptide built from 44 amino acids and classified with the growth hormone–releasing hormone family. Its sequence corresponds to the human GHRH(1-44) backbone, carrying one structural change at the amino terminus. That change is a trans-3-hexenoyl group placed where the natural peptide would have an unmodified end. The modification is the feature that separates the compound from the endogenous hormone in name, in stability, and in how it is handled in the laboratory.
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass and detects chemical modifications. Peptide mapping and amino acid analysis can verify sequence integrity. Water content is measured by Karl Fischer titration, and residual solvents may be checked by gas chromatography. These methods together support batch-to-batch consistency and routine quality control.
Lyophilized tesamorelin is generally stored refrigerated at temperatures between 2 and 8 degrees Celsius. The solid form is comparatively stable when kept dry and protected from light. Moisture uptake can promote aggregation and degradation, so sealed containers with desiccant are common. Researchers typically avoid repeated temperature cycling, which may stress the peptide. Documentation accompanying reference materials usually specifies a shelf life under these conditions.
Although a rate law provides the stoichiometry of the transition state structure, it does not provide any information about breaking or forming bonds. The substitution of an isotope near a reactive position often leads to a change in the rate of a reaction. Isotopic substitution changes the potential energy of reaction intermediates and transition states because heavier isotopes form stronger bonds with other atoms. Atomic mass affects the zero-point vibrational state of the associated molecules, shorter and stronger bonds in molecules with heavier isotopes and longer, weaker bonds in molecules with light isotopes. Because vibrational motions will often change during a course of a reaction, due to the making and breaking of bonds, the frequencies will be affected, and the substitution of an isotope can provide insight into the reaction mechanism and rate law.
Dry ice is the solid form of carbon dioxide (CO2), a molecule consisting of a single carbon atom bonded to two oxygen atoms. Dry ice is colorless, odorless, and non-flammable, and can lower the pH of a solution when dissolved in water, forming carbonic acid (H2CO3). At pressures below 5.13 atm and temperatures below −56.4 °C (216.8 K; −69.5 °F) (the triple point), CO2 changes from a solid to a gas with no intervening liquid form, through a process called sublimation. The opposite process is called deposition, where CO2 changes from the gas to solid phase (dry ice). At atmospheric pressure, sublimation/deposition occurs at 194.7 K (−78.5 °C; −109.2 °F). The density of dry ice increases with decreasing temperature and ranges between about 1.55 and 1.7 g/cm3 (97 and 106 lb/cu ft) below 195 K (−78 °C; −109 °F). The low temperature and direct sublimation to a gas makes dry ice an effective coolant, since it is colder than water ice and leaves no residue as it changes state. Its enthalpy of sublimation is 571 kJ/kg (25.2 kJ/mol, 136.5 calorie/g). Dry ice is non-polar, with a dipole moment of zero, so attractive intermolecular van der Waals forces operate. The composition results in low thermal and electrical conductivity.
== Etymology == The term tempe is thought to be derived from the Old Javanese tumpi, a whitish food made of fried batter made from sago or rice flour which resembles rempeyek. The historian Denys Lombard also suggests that it could be linked to a later term tape or tapai which means 'fermentation'. In the western world, tempeh rather than tempe is the most common spelling, to emphasise that the final "e" is pronounced. The first known usage of this spelling is in an 1896 German article. Other spellings, such as témpé, were also used, but tempeh has become the standard spelling in English since the 1960s.
This recommendation by the INCB has been criticized as an attempt by the Board to overstep its legitimate mandate and as establishing a reason for governments to violate the human rights (i.e., religious freedom) of ceremonial ayahuasca drinkers. Under American federal law, DMT is a Schedule I drug that is illegal to possess or consume; however, certain religious groups have been legally permitted to consume ayahuasca. A court case allowing the União do Vegetal to import and use the tea for religious purposes in the United States, Gonzales v. O Centro Espírita Beneficente União do Vegetal, was heard by the U.S. Supreme Court on November 1, 2005; the decision, released February 21, 2006, allows the UDV to use the tea in its ceremonies pursuant to the Religious Freedom Restoration Act. In a similar case in Ashland, Oregon-based Santo Daime church sued for their right to import and consume ayahuasca tea. In March 2009, U.S. District Court Judge Panner ruled in favor of the Santo Daime, acknowledging its protection from prosecution under the Religious Freedom Restoration Act. In 2017 the Santo Daime Church Céu do Montréal in Canada received religious exemption to use ayahuasca as a sacrament in their rituals. Religious use in Brazil was legalized after two official inquiries into the tea in the mid-1980s, which concluded that ayahuasca is not a recreational drug and has valid spiritual uses.
Sources: en.wikipedia.org
PLGA is typically synthesized by ring-opening polymerization of the cyclic dimers lactide and glycolide, a method widely used because it allows better control over molecular weight and copolymer composition than direct condensation methods. Other reports show direct polycondensation of lactic acid and glycolic acid as another method, but this approach gives lower molecular weight material and is less suitable for producing controlled, high-performance PLGA grades. Common catalysts include tin(II) 2-ethylhexanoate and related organometallic catalysts, which are widely used in melt polymerization because of their activity and practical availability.
Sporulation is stimulated by amino acids (except L-valine) when grown in light, while in darkness only L-tryptophan and L-methionine effect stimulation of growth. The columellae are globose, subglobose, or oval in shape. The wall is usually smooth and the colour is pale brown. The average diameter growth ranges from 30-110 μm. Sporangiospores are elliptical, globose, or polygonal, they are striated and grow 5-8 μm in length. Dormant and germinated sporangiospores show deep furrows and prominent ridges with a pattern that makes it distinguishable from that of R. stolonifer. The germination of sporangiospores can be induced by the combined action of L-proline and phosphate ions. L-ornithine, L-arginine, D-glucose and D-mannose are also effective. Optimal germination occurs on media containing D-glucose and mineral salts.R. oryzae has abundant, root-shaped rhizoids. Zygospores are produced by diploid cells when sexual reproduction occurs under nutrient poor conditions. They have colors that range from red to brown, they are spherical or laterally flattened, and ranges from 60-140μm in size. In high nutrient levels, R. oryzae reproduces asexually, producing azygospores. The stolons found in R. oryzae are smooth or slightly rough, almost colorless or pale brown, 5-18 μm in diameter. The chlamydospores are abundant, globose ranging in 10-24 μm in diameter, elliptical, and cylindrical. Colonies of R. oryzae are white initially, becoming brownish with age and can grow to about 1 cm thick.
== Biosynthesis == The biosynthesis of menthol has been investigated in Mentha × piperita and the enzymes involved in have been identified and characterized. It begins with the synthesis of the terpene limonene, followed by hydroxylation, and then several reduction and isomerization steps. More specifically, the biosynthesis of (−)-menthol takes place in the secretory gland cells of the peppermint plant. The steps of the biosynthetic pathway are as follows:
=== Metal oxide === Metal oxide aerogels are used as catalysts in various chemical reactions/transformations or as precursors for other materials. Aerogels made with aluminium oxide are known as alumina aerogels. These aerogels are used as catalysts, especially when "doped" with a metal other than aluminium. Nickel–alumina aerogel is the most common combination. Alumina aerogels are also being considered by NASA for capturing hypervelocity particles; a formulation doped with gadolinium and terbium could fluoresce at the particle impact site, with the amount of fluorescence dependent on impact energy. One of the most notable differences between silica aerogels and metal oxide aerogel is that metal oxide aerogels are often variedly colored.
== History == French pharmaceutical company Hoechst Marion Roussel (later Sanofi-Aventis) began phase II/III clinical trials of telithromycin (HMR-3647) in 1998. Telithromycin was approved by the European Commission in July 2001 and subsequently went on sale in October 2001. In the US, telithromycin received U.S. Food and Drug Administration (FDA) approval on April 1, 2004.
Sources: en.wikipedia.org
=== Elimination of suprabony fibrous and firm pockets === Gingivectomy is the primary treatment method available in reducing the pocket depths of patients with periodontitis and suprabony pockets. In a retrospective comparison between different treatment approach to periodontitis management based on the initial and final gingival health, conventional gingivectomy was proven to be more successful in reducing pocket depths and inflammation compared to non-surgical treatments in pockets measured 3mm or more. Removal of suprabony deep pockets will allow better visibility and access for the removal of calculus. As a result, this provides a suitable environment for the healing of the gingiva and the physiological contour of the gingiva to be restored.
MS2 tagging is a technique based upon the natural interaction of the MS2 bacteriophage coat protein with a stem-loop structure from the phage genome, which is used for biochemical purification of RNA-protein complexes and partnered to GFP for detection of RNA in living cells. More recently, the technique has been used to monitor the appearance of RNA in living cells, at the site of transcription, or simply by observing the changes in RNA number in the cytoplasm. This has revealed that transcription of both prokaryotic and eukaryotic genes occurs in a discontinuous fashion with bursts of transcription separated by irregular intervals.
In cell biology, protein turnover refers to the replacement of older proteins as they are broken down within the cell. Different types of proteins have very different turnover rates. A balance between protein synthesis and protein degradation is required for good health and normal protein metabolism. More synthesis than breakdown indicates an anabolic state that builds lean tissues, more breakdown than synthesis indicates a catabolic state that burns lean tissues. According to D.S. Dunlop, protein turnover occurs in brain cells the same as any other eukaryotic cells, but that "knowledge of those aspects of control and regulation specific or peculiar to brain is an essential element for understanding brain function." Protein turnover is believed to decrease with age in all senescent organisms including humans. This results in an increase in the amount of damaged protein within the body.
Vitamin B12 is derived from a tetrapyrrolic structural framework created by the enzymes deaminase and cosynthetase which transform aminolevulinic acid via porphobilinogen and hydroxymethylbilane to uroporphyrinogen III. The latter is the first macrocyclic intermediate common to heme, chlorophyll, siroheme and B12 itself. Later steps, especially the incorporation of the additional methyl groups of its structure, were investigated using 13C methyl-labeled S-adenosyl methionine. It was not until a genetically engineered strain of Pseudomonas denitrificans was used, in which eight of the genes involved in the biosynthesis of the vitamin had been overexpressed, that the complete sequence of methylation and other steps could be determined, thus fully establishing all the intermediates in the pathway. Species from the following genera and the following individual species are known to synthesize B12: Propionibacterium shermanii, Pseudomonas denitrificans, Streptomyces griseus, Acetobacterium, Aerobacter, Agrobacterium, Alcaligenes, Azotobacter, Bacillus, Clostridium, Corynebacterium, Flavobacterium, Lactobacillus, Micromonospora, Mycobacterium, Nocardia, Proteus, Rhizobium, Salmonella, Serratia, Streptococcus and Xanthomonas.
Sources: en.wikipedia.org
It is a laboratory-made peptide of forty-four amino acids whose sequence matches human growth hormone-releasing hormone, with a modified amino terminus. The modification is a short unsaturated fatty acid chain attached to the first residue. This change slows enzymatic breakdown and lengthens the time the peptide stays active in circulation.
The clinical program was designed around HIV-associated lipodystrophy, a condition in which fat accumulates abnormally around the internal organs. Trials enrolled that specific population, so the evidence base covers it rather than the general population. Regulators approved the drug for the studied indication only, and promotion outside it is not permitted.
Growth hormone therapy supplies the finished hormone directly, while this peptide acts upstream and asks the pituitary to secrete its own. That difference means the response depends on a functioning pituitary and on the body's normal feedback loops. It also means the circulating hormone profile is pulsatile rather than a flat, injected level.
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.