The short version of somatotroph fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Tesamorelin is a synthetic peptide that belongs to the growth hormone-releasing hormone (GHRH) family. Its sequence corresponds to the fully active 44-amino-acid form of human GHRH, with a single structural modification: the addition of a trans-3-hexenoyl group at the N-terminus. That modification is not found in the naturally occurring hormone and was introduced deliberately during development to improve stability against enzymatic degradation. The compound is therefore best described as a stabilized analogue rather than a naturally occurring peptide.
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 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.
Tesamorelin occupies a narrow position among agents that act on the growth hormone axis. Unlike growth hormone itself, which is given as replacement, it stimulates the pituitary to release the hormone in pulses, so the downstream increase in insulin-like growth factor 1 depends on intact somatotroph function. Other peptides in the same family include shorter GHRH fragments and synthetic secretagogues with different stability profiles. Several points remain unresolved, including whether the reduction in visceral fat translates into fewer cardiovascular events, what happens to metabolic markers after long-term use, and how the drug compares with lifestyle or surgical approaches.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C221H366N72O67S | Reflects a 44-residue peptide with one N-terminal modification |
| Approximate molecular weight | 5136 Da | Sequence length and single acyl group determine the mass |
| Appearance | White to off-white lyophilized powder | Typical form of a purified synthetic peptide |
| Solubility class | Soluble in water and aqueous buffer | Peptide backbone favors aqueous dissolution |
| Common synonyms | GHRH(1-44) analogue; Egrifta | Descriptive name and approved brand name |
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.
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.
Madak was a blend of opium and tobacco used as a recreational drug in 16th- and 17th-century China. It emerged in southern coastal areas in the first half of the 17th century. In the last quarter of the 18th century madak was phased out by raw opium. The prohibition of madak in 1729 may have been a contributing factor to the increase in popularity of smoking pure opium. Raw opium was introduced in China by Arab merchants. Rather than taking bitter raw opium orally, the Chinese attempted smoking opium mixed with other substances. According to Dikotter et al., smoking opium blended with tobacco was introduced in China by the Dutch traders between 1624 and 1660. Madak was prepared by blending opium from Java with domestic Chinese hemp and herbs, boiling the mix in pans and, finally, mixing with tobacco. It was smoked in bamboo pipes with coir fibre filter. The new addiction was limited to coastal territories around Taiwan Strait; further spread was hampered by the civil war that accompanied the fall of the Ming Dynasty. The new Qing Dynasty government was not aware of madak until 1683. The lucrative opium business continued spreading along the coast of Southern China, although exact chronology of this spread remains unknown. By 1720 the government saw madak smoking as a social evil that has corrupted not just the lowest classes, but the "good families" too. Smoking dens, where people congregated at night, were deemed as dangerous as heretical cults and political conspiracies. In 1729 the Yongzheng Emperor banned recreational smoking of madak. Medicinal use remained permitted.
it includes pre-analytical, analytical and post-analytical phases, each with the same importance; it is most often based on the specific, accurate, precise and timely determinations of the active and.or toxic forms of drugs in biological samples collected at the appropriate times in the correct containers (PK monitoring), or can employ the measurement of a biological perimeter as a surrogate or end-point marker of effect (PD monitoring) e.g. concentration of an endogenous compound, enzymatic activity, gene expression, etc. either as a complement to PK monitoring or as the main TDM tool; it requires interpretation of the results, taking into account pre-analytical conditions, clinical information and the clinical efficiency of the current dosage regimen; this can be achieved by the application of PK-PD modeling; it can potentially benefit from population PK/PD models possibly combined with individual pharmacokinetic forecasting techniques, or pharmacogenetic data.
known as dissociation in the context of acid–base reactions. The chemical species HA is an acid that dissociates into A−, called the conjugate base of the acid, and a hydrogen ion, H+. The system is said to be in equilibrium when the concentrations of its components do not change over time, because both forward and backward reactions are occurring at the same rate. The dissociation constant is defined by
Sources: en.wikipedia.org
=== Disease === Disease can arise if the host's protective immune mechanisms are compromised and the organism inflicts damage on the host. Microorganisms can cause tissue damage by releasing a variety of toxins or destructive enzymes. For example, Clostridium tetani releases a toxin that paralyzes muscles, and staphylococcus releases toxins that produce shock and sepsis. Not all infectious agents cause disease in all hosts. For example, less than 5% of individuals infected with polio develop disease. On the other hand, some infectious agents are highly virulent. The prion causing mad cow disease and Creutzfeldt–Jakob disease invariably kills all animals and people that are infected. Persistent infections occur because the body is unable to clear the organism after the initial infection. Persistent infections are characterized by the continual presence of the infectious organism, often as latent infection with occasional recurrent relapses of active infection. There are some viruses that can maintain a persistent infection by infecting different cells of the body. Some viruses once acquired never leave the body. A typical example is the herpes virus, which tends to hide in nerves and become reactivated when specific circumstances arise. Persistent infections cause millions of deaths globally each year. Chronic infections by parasites account for a high morbidity and mortality in many underdeveloped countries.
== Regulation == Anabolism operates with separate enzymes from catalysis, which undergo irreversible steps at some point in their pathways. This allows the cell to regulate the rate of production and prevent an infinite loop, also known as a futile cycle, from forming with catabolism. The balance between anabolism and catabolism is sensitive to ADP and ATP, otherwise known as the energy charge of the cell. High amounts of ATP cause cells to favor the anabolic pathway and slow catabolic activity, while excess ADP slows anabolism and favors catabolism. These pathways are also regulated by circadian rhythms, with processes such as glycolysis fluctuating to match an animal's normal periods of activity throughout the day.
After this change, only the larger engine with lean-burn technology was available in the home market, now with 72 PS (53 kW; 71 hp) (JIS gross) and labelled Familia Presto 1300AP (for "Anti Pollution").
Sources: en.wikipedia.org
=== EC 1.14.19 With oxidation of a pair of donors resulting in the reduction of O2 to two molecules of water === EC 1.14.19.1: stearoyl-CoA 9-desaturase EC 1.14.19.2: stearoyl-[acyl-carrier-protein] 9-desaturase EC 1.14.19.3: linoleoyl-CoA desaturase EC 1.14.19.4: acyl-lipid (11-3)-desaturase EC 1.14.19.5: acyl-CoA 11-(Z)-desaturase EC 1.14.19.6: acyl-CoA (9+3)-desaturase EC 1.14.19.7: Now EC 1.11.1.23, (S)-2-hydroxypropylphosphonic acid epoxidase EC 1.14.19.8: pentalenolactone synthase EC 1.14.19.9: tryptophan 7-halogenase EC 1.14.19.10: icosanoyl-CoA 5-desaturase EC 1.14.19.11: acyl-[acyl-carrier-protein] 4-desaturase EC 1.14.19.12: acyl-lipid ω-(9-4) desaturase EC 1.14.19.13: acyl-CoA 15-desaturase EC 1.14.19.14: linoleoyl-lipid Δ9 conjugase EC 1.14.19.15: (11Z)-hexadec-11-enoyl-CoA conjugase EC 1.14.19.16: linoleoyl-lipid Δ12 conjugase (11E,13Z-forming) EC 1.14.19.17: sphingolipid 4-desaturase EC 1.14.19.18: sphingolipid 8-(E)-desaturase EC 1.14.19.19: sphingolipid 10-desaturase EC 1.14.19.20: Δ7-sterol 5(6)-desaturase EC 1.14.19.21: cholesterol 7-desaturase EC 1.14.19.22: acyl-lipid ω-6 desaturase (cytochrome b5) EC 1.14.19.23: acyl-lipid (n+3)-(Z)-desaturase (ferredoxin) EC 1.14.19.24: acyl-CoA 11-(E)-desaturase EC 1.14.19.25: acyl-lipid ω-3 desaturase (cytochrome b5) EC 1.14.19.26: acyl-[acyl-carrier-protein] 6-desaturase EC 1.14.19.27: sn-2 palmitoyl-lipid 9-desaturase EC 1.14.19.28: sn-1 stearoyl-lipid 9-desaturase EC 1.14.19.29: sphingolipid 8-(E/Z)-desaturase EC 1.14.19.30: acyl-lipid (8-3)-desaturase EC 1.14.19.31: acyl-lipid (7-3)-desaturase EC 1.14.19.32: palmitoyl-CoA 14-(E/Z)-desaturase EC 1.14.19.33: Δ12 acyl-lipid conjugase (11E,13E-forming) EC 1.14.19.34: acyl-lipid (9+3)-(E)-desaturase EC 1.14.19.35: sn-2 acyl-lipid ω-3 desaturase (ferredoxin) EC 1.14.19.36: sn-1 acyl-lipid ω-3 desaturase (ferredoxin) EC 1.14.19.37: acyl-CoA 5-desaturase EC 1.14.19.38: acyl-lipid Δ6-acetylenase EC 1.14.19.39: acyl-lipid Δ12-acetylenase EC 1.14.19.40: hex-5-enoyl-[acyl-carrier protein] acetylenase EC 1.14.19.41: sterol 22-desaturase EC 1.14.19.42: palmitoyl-[glycerolipid] 7-desaturase EC 1.14.19.43: palmitoyl-[glycerolipid] 3-(E)-desaturase EC 1.14.19.44: acyl-CoA (8-3)-desaturase EC 1.14.19.45: sn-1 oleoyl-lipid 12-desaturase EC 1.14.19.46: sn-1 linoleoyl-lipid 6-desaturase EC 1.14.19.47: acyl-lipid (9-3)-desaturase EC 1.14.19.48: tert-amyl alcohol desaturase EC 1.14.19.49: tetracycline 7-halogenase EC 1.14.19.50: noroxomaritidine synthase EC 1.14.19.51: (S)-corytuberine synthase EC 1.14.19.52: camalexin synthase EC 1.14.19.53: all-trans-retinol 3,4-desaturase EC 1.14.19.54: 1,2-dehydroreticuline synthase EC 1.14.19.55: 4-hydroxybenzoate brominase (decarboxylating) EC 1.14.19.56: 1H-pyrrole-2-carbonyl-[peptidyl-carrier protein] chlorinase EC 1.14.19.57: 1H-pyrrole-2-carbonyl-[peptidyl-carrier protein] brominase EC 1.14.19.58: tryptophan 5-halogenase EC 1.14.19.59: tryptophan 6-halogenase EC 1.14.19.60: 7-chloro-L-tryptophan 6-halogenase EC 1.14.19.61: dihydrorhizobitoxine desaturase EC 1.14.19.62: secologanin synthase EC 1.14.19.63: pseudobaptigenin synthase EC 1.14.19.64: (S)-stylopine synthase EC 1.14.19.65: (S)-cheilanthifoline synthase EC 1.14.19.66: berbamunine synthase EC 1.14.19.67: salutaridine synthase EC 1.14.19.68: (S)-canadine synthase EC 1.14.19.69: biflaviolin synthase EC 1.14.19.70: mycocyclosin synthase EC 1.14.19.71: fumitremorgin C synthase EC 1.14.19.72: (–)-pluviatolide synthase EC 1.14.19.73: (S)-nandinine synthase EC 1.14.19.74: (+)-piperitol/(+)-sesamin synthase EC 1.14.19.75: very-long-chain acyl-lipid ω-9 desaturase EC 1.14.19.76: flavone synthase II EC 1.14.19.77: plasmanylethanolamine desaturase EC 1.14.19.78: decanoyl-[acyl-carrier protein] acetylenase
Applied Biosystems is one of various brands under the Life Technologies brand of Thermo Fisher Scientific corporation. The brand is focused on integrated systems for genetic analysis, which include computerized machines and the consumables used within them (such as reagents). In 2008, a merger between Applied Biosystems and Invitrogen was finalized, creating Life Technologies. The latter was acquired by Thermo Fisher Scientific in 2014. Prior to 2008, the Applied Biosystems brand was owned by various entities in a corporate group parented by PerkinElmer. The roots of Applied Biosystems trace back to GeneCo (Genetic Systems Company), a pioneer biotechnology company founded in 1981 in Foster City, California. Through the 1980s and early 1990s, Applied Biosystems, Inc. operated independently and manufactured biochemicals and automated genetic engineering and diagnostic research instruments, including the principal brand of DNA sequencing machine used by the Human Genome Project consortium centers. Applied Biosystems' close ties to the consortium project led to the idea for the founding of Celera Genomics in 1998 as one of several independent competitors to the consortium. In 1993 Applied Biosystems, Inc., was delisted from the NASDAQ when it was acquired by the old company known then as Perkin-Elmer. As the PE Applied Biosystems Division under that parent in 1998, it became consolidated with other acquisitions as the primary PE Biosystems Division.
=== Bernot et al. (2023) === In recent study, Bernot et al. placed Copepoda as a sister group to Branchiopoda in Allotriocarida, which result in the recovery of clade Communostraca. Multicrustacea was not found. There are some major changes within class Malacostraca.
Sources: en.wikipedia.org
It shares the 44-residue sequence of human GHRH but carries an added trans-3-hexenoyl group at its N-terminus. That addition does not occur in the natural hormone and serves mainly to resist enzymatic breakdown. The receptor target and signaling pathway remain the same.
It binds the growth hormone-releasing hormone receptor on anterior pituitary cells. Activation of that receptor promotes synthesis and release of growth hormone. The effect propagates through the growth hormone and insulin-like growth factor 1 axis.
Native GHRH is cleared quickly by peptidases, which limits how long it can stimulate its receptor. The added group hinders one of the primary cleavage enzymes. The practical consequence is a longer period of receptor activity per dose.
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.