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.
Last reviewed on 2025-09-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
A documented effect of tesamorelin is a reduction in visceral adipose tissue in some study populations. Researchers have reported decreases in trunk fat measured by computed tomography alongside changes in lipid markers. The mechanism is thought to involve growth hormone-mediated lipolysis, though the precise contribution of direct versus indirect pathways is not fully resolved. Studies have generally examined defined groups over finite periods, so long-term outcomes are less well characterized. Findings have not been uniform across all trials.
Tesamorelin is a synthetic peptide analog of growth hormone-releasing hormone (GHRH). Its sequence corresponds to the 44-amino-acid form of human GHRH with a trans-3-hexenoyl group attached to the N-terminal tyrosine. This modification slows enzymatic cleavage and extends the peptide's activity relative to the native hormone. The compound is produced by solid-phase peptide synthesis and supplied as a lyophilized powder. Researchers classify it as a GHRH receptor agonist. Its structure places it in the same family as other growth hormone secretagogues that act on the pituitary.
Binding of tesamorelin to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and the release of growth hormone into circulation. Because the peptide acts upstream of the growth hormone axis, its effects are partly mediated by hepatic insulin-like growth factor 1 (IGF-1) production. The pulsatile character of endogenous growth hormone secretion is preserved rather than replaced. Whether amplified signaling produces effects beyond those of native GHRH remains an area of ongoing investigation.
| 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 |
Questions remain about how much of the observed fat reduction reflects direct GHRH-receptor signaling versus the downstream growth hormone and IGF-1 surge. It is also unclear whether the compound produces meaningful benefit in populations without lipodystrophy, since trials in cognitive impairment did not reach their stated goals. Long-term effects on glucose metabolism and on cardiovascular outcomes are not fully characterized. Published work generally describes effects on surrogate markers rather than on hard clinical endpoints, and independent replication of some findings is limited.
Tesamorelin acts on the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in intracellular cyclic AMP, which in turn opens ion channels and raises calcium concentrations, leading to release of stored growth hormone into the bloodstream. Because the peptide works through the same receptor as the body's own GHRH, the resulting secretion follows a pulsatile pattern rather than a continuous elevation. The N-terminal modification slows enzymatic breakdown, so the signal persists longer than it would with the unmodified hormone.
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.
In the case of chain-end scission, monomers are released and this process is referred to as unzipping or depolymerization. Which mechanism dominates will depend on the type of polymer and temperature; in general, polymers with no or a single small substituent in the repeat unit will decompose via random-chain scission. The sorting of polymer waste for recycling purposes may be facilitated by the use of the resin identification codes developed by the Society of the Plastics Industry to identify the type of plastic.
The Garinagu (singular Garifuna), at around 4.5% of the population, are a mix of West/Central African, Arawak, and Island Carib ancestry. Though they were captives removed from their homelands, these people were never documented as slaves. The two prevailing theories are that, in 1635, they were either the survivors of two recorded shipwrecks or somehow took over the ship they came on. Throughout history they have been incorrectly labelled as Black Caribs. When the British took over Saint Vincent and the Grenadines after the Treaty of Paris in 1763, they were opposed by French settlers and their Garinagu allies. The Garinagu eventually surrendered to the British in 1796. The British separated the more African-looking Garifunas from the more indigenous-looking ones. 5,000 Garinagu were exiled from the Grenadine island of Baliceaux. About 2,500 of them survived the voyage to Roatán, an island off the coast of Honduras. The Garifuna language belongs to the Arawakan language family, but has a large number of loanwords from Carib languages and from English. Because Roatán was too small and infertile to support their population, the Garinagu petitioned the Spanish authorities of Honduras to be allowed to settle on the mainland coast. The Spanish employed them as soldiers, and they spread along the Caribbean coast of Central America. The Garinagu settled in Seine Bight, Punta Gorda and Punta Negra, Belize, by way of Honduras as early as 1802. In Belize, 19 November 1832 is the date officially recognized as "Garifuna Settlement Day" in Dangriga.
==== Approved topical medicine ==== In the European Union, a prescription gel containing birch bark extract (commercial name Episalvan, betulae cortex dry extract (5–10 : 1); extraction solvent: n-heptane 95% (w/w)) was approved in 2016 for the topical treatment of minor skin wounds in adults. Although its mechanism of action in helping to heal injured skin is not fully understood, birch bark extract appears to stimulate the growth of keratinocytes which then fill the wound.
=== Artificial retina === The artificial retina of Professor José Sahel and his team at the Quinze-Vingts National Ophthalmology Hospital Centre aims to allow people with degenerative retinal disease, numbering 1.5 million in 2008, to accomplish everyday activities. Placed under the existing retina, it directly stimulates the neurons, replacing defective cells. These implants should eventually allow patients to recognize faces, read large print and move independently in a restricted environment. The challenge for the Altran teams was to find solutions to produce artificial retina in series, in order to bring solutions to the widest number of patients.
To infect host cells SeV must first bind to cell surface receptors using its hemagglutinin-neuraminidase (HN) protein. The receptor-virus attaching process triggers a conformational change in HN, which allosterically promotes the viral fusion (F) protein to promote virus envelope – cell membrane fusion. The receptor attachment is cooperative with respect to receptor density. SeV cell entry receptors are represented mainly by glycoproteins and glycolipids. The table below lists all the molecules that have been shown to function as SeV receptors. Human sialoglycoprotein – cluster of differentiation (CD 235a) is an example of glycoproteins that facilitates SeV cell entry. However, other type of proteins that are not glycoproteins also can assist SeV to penetrate cells. Thus, C-type lectin represented by asialoglycoprotein receptor (ASGP-R), ASGR1) has been shown to be able to function as a SeV cell entry receptor. Among glycosphingolipids two types of glycans are serving as SeV receptors. The first type is represented by fucosylated glycans and the second one by sialylated glycans. The number, positioning, and chemical linkage of sialic acid-containing receptors can be an important determinant of the strength and efficiency of viral attachment, which can play an important role both in host and tissue tropism. The expression of molecules that can facilitate SeV cell entry, frequently accelerates carcinogenesis and metastasis development. The asialoglycoprotein receptor is highly expressed in liver cancers.
Sources: en.wikipedia.org
== Further reading == Watkins, Steve (29 June 2018). "Which Cincinnati public company CEO delivers the best bang for the buck? (Video)". Cincinnati Business Courier. American City Business Journals. Retrieved 31 Aug 2019. It's rare to see a CEO make less money than a CFO or an executive vice president. But that's how it worked last year at Medpace Holdings Inc....
=== President and Past Presidents (since 1953) === 2022–2024 Julia Laskin 2020–2022 Susan Richardson 2016–2018 Vicki Wysocki 2014–2016 Jennifer Brodbelt 2012–2014 Susan Weintraub 2006–2008 Barbara S. Larsen 2002–2004 Catherine E. Costello 1996–1998 Veronica M. Bierbaum 1982–1984 Catherine Fenselau
== Mechanism of action == Nitrovasodilators are prodrugs that donate NO by various mechanisms. Nitrates undergo chemical reduction, likely mediated by enzymes. Molsidomine and nitroprusside already contain nitrogen in the right oxidation state (+2) and liberate NO without the aid of enzymes. NO stimulates the soluble form of the enzyme guanylate cyclase in the smooth muscle cells of blood vessels. Guanylate cyclase produces cyclic guanosine monophosphate (cGMP) from guanosine triphosphate (GTP). cGMP in turn activates cyclic nucleotide-dependent protein kinase G, which phosphorylates various proteins that play a role in decreasing intracellular calcium levels, leading to relaxation of the muscle cells and thus to dilation of blood vessels. The most important effect in angina is the widening of veins, which increases their capacity to hold blood ("venous pooling") and reduces the pressure of the blood returning to the heart (the preload). Widening of the large arteries also reduces the pressure against which the heart has to pump, the afterload. Lower preload and afterload result in the heart needing less energy and thus less oxygen. Besides, NO donated by nitrovasodilators can reduce coronary spasms, increasing the heart's oxygen supply. PDE5 inhibitors block deactivation of cGMP by the enzyme phosphodiesterase-5. In combination with the increased cGMP production caused by nitrovasodilators, this leads to high concentrations of cGMP, extensive venous pooling, and potentially life-threatening hypotension.
The current epidemic of obesity and eating disorders undermines these theories. The set point theories of hunger and eating are inconsistent with basic evolutionary pressures related to hunger and eating as they are currently understood. Major predictions of the set point theories of hunger and eating have not been confirmed. They fail to recognize other psychological and social influences on hunger and eating.
This method uses stable isotopes into probe-derived tags to improve the sensitivity and selectivity of ABPP, while also enabling accurate quantification of protein interactions in complex biological samples. In addition, fluorescent and photoaffinity probes can be applied in situ or in vivo to visualize enzyme activity within cells, tissues, or whole organisms. These approaches provide spatial information about enzyme function and have been used to study processes such as protease activity in cancer and infection models. Emerging designs aim to enable real-time, non-invasive imaging of enzyme activity in living systems.
Sources: en.wikipedia.org
About 95 minutes after launch, the satellite flew over its launch site, and its radio signals were picked up by the engineers and military personnel at Tyura-Tam: that's when Korolev and his team celebrated the first successful artificial satellite placed into Earth-orbit. The next satellite sent by the Soviets after Sputnik 1 was Sputnik 2, launched on November 3, 1957, just a month later. This would put the first animal into orbit.
Plants that cause illness or death after consuming them are referred to as poisonous plants. The toxins in poisonous plants affect herbivores, and deter them from consuming the plants. Plants cannot move to escape their predators, so they must have other means of protecting themselves from herbivorous animals. Some plants have physical defenses such as thorns, spines and prickles, but by far the most common type of protection is chemical. Over millennia, through the process of natural selection, plants have evolved the means to produce a vast and complicated array of chemical compounds to deter herbivores. Tannin, for example, is a defensive compound that emerged relatively early in the evolutionary history of plants, while more complex molecules such as polyacetylenes are found in younger groups of plants such as the Asterales. Many of the known plant defense compounds primarily defend against consumption by insects, though other animals, including humans, that consume such plants may also experience negative effects, ranging from mild discomfort to death. Many of these poisonous compounds also have important medicinal benefits. The varieties of phytochemical defenses in plants are so numerous that many questions about them remain unanswered, including:
Small amounts of melamine have also been reported in foodstuff as a metabolite product of cyromazine, an insecticide used on animals and crops. The Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA) provides a test method for analyzing cyromazine and melamine in animal tissues. In 2007, the FDA began using a high performance liquid chromatography test to determine the melamine, ammeline, ammelide, and cyanuric acid contamination in food. Another procedure is based on surface-enhanced Raman spectroscopy (SERS). Member states of the European Union are required under Commission Decision 2008/757/EC to ensure that all composite products containing at least 15% of milk product, originating from China, are systematically tested before import into the Community and that all such products which are shown to contain melamine in excess of 2.5 mg/kg are immediately destroyed. Following the 2008 melamine milk scandal, China restructured its food safety system by implementing the Food Safety Law, introducing stricter dairy industry regulations, and establishing independent third-party inspections to strengthen oversight and restore public trust. The 2009 Food Safety Law also reorganized government oversight by placing food safety regulation under a uniform national framework that employs risk-based standards and adheres to international Codex Alimentarius Commission guidelines.
== External links == Overview at colostate.edu Secretin at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Nosek TM. "Section 6/6ch2/s6ch2_17". Essentials of Human Physiology. Archived from the original on 2016-03-24.
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 mirrors the 44-residue form of human growth hormone-releasing hormone. A hexenoyl group on the N-terminal tyrosine distinguishes it from the unmodified hormone. The change is intended to improve resistance to enzymatic breakdown.