The short version of somatotroph fits in a sentence. The long version — which is the one that helps — is below.
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Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.
Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.
CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.
| Property | Value | Notes |
|---|---|---|
| Physical form | Lyophilized white powder | Supplied as a freeze-dried solid for research use |
| Molecular weight | Approximately 3,647 Da (DAC form) | Lower for the variant lacking the albumin-binding moiety |
| Solubility | Soluble in water and aqueous buffer | Typically dissolved in sterile or bacteriostatic water |
| Typical storage temperature | −20 °C or below | Dry powder, desiccated and protected from light |
| Common analytical method | Reversed-phase HPLC with mass spectrometry | Used for purity estimation and identity confirmation |
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
Binding of the peptide to the growth hormone-releasing hormone receptor on pituitary somatotrophs triggers a G protein coupled cascade that raises cyclic AMP and opens calcium channels. The result is greater secretion of growth hormone into the bloodstream. Because the peptide acts at the same receptor as the natural hypothalamic hormone, its effect is amplified pulse size rather than an entirely separate release pathway. Receptor binding alone does not determine the response, since somatostatin tone and other inputs modulate the final output.
The albumin-binding version stays in circulation for days, because covalent attachment to serum albumin shields the peptide from rapid filtration and degradation. Reported half-lives for this form fall in the range of several days. The version without the linker is cleared in minutes, with estimates often near thirty minutes in animal work. These figures come from small studies and vary with assay method, species, and route, so they are best read as approximate rather than fixed constants.
== Pharmacokinetics == Abciximab has a plasma half-life of about ten minutes, with a second phase half-life of about 30 minutes. However, its effects on platelet function can be seen for up to 48 hours after the infusion has been terminated, and low levels of glycoprotein IIb/IIIa receptor blockade are present for up to 15 days after the infusion is terminated. Abciximab does not require dose adjustments for patients with kidney failure.
== Education == Chandan Sen earned his Bachelor of Science degree (Honors in Physiology) in 1987 and his Master of Science in Human Physiology in 1990 from the Rajabazar Science College at Calcutta University. He subsequently moved to Finland for advanced studies and received his Ph.D. in Physiology in 1994 from the School of Medicine at the University of Eastern Finland (Kuopio Campus). In January 1995, Sen joined the University of California, Berkeley for postdoctoral research in the Department of Molecular and Cell Biology, focusing on redox signaling (1995–1996). In 1997, Sen accepted his first faculty appointment at the Lawrence Berkeley National Laboratory in Berkeley, California.
== History == Frederick L. "Freddy" Simon grew up in Colwich, Kansas, near Wichita. He was a World War II veteran, joining the U.S. Army infantry in 1943 and serving in the 1st Cavalry Division. He was awarded the Purple Heart due to combat wounds sustained in the Pacific Theater, as well as a Bronze Star for valor. After the war, Simon worked for the same company in the hospitality industry for 55 years, building connections with many restaurateurs. Freddy lent his name to, and was a business partner in, a Simon family-owned restaurant called Freddy's Frozen Custard & Steakburgers. Founded by his sons Randy and Bill and Bill's friend, restaurateur Scott Redler, the first location opened in Wichita on August 26, 2002. Freddy's quickly gained a loyal customer base, leading to further expansion beginning in 2004. Freddy's menu has remained consistent over the years, offering signature steakburgers, Vienna Beef hot dogs, and fresh frozen custard desserts across all locations. The food was based on "All American" meals that Freddy had served his own family, with the setting of the restaurant based on fast-casual dining of the late 1940s and early 1950s, evoking "a post-war era of optimism, pride, and values focusing on unity and quality family time." On December 17, 2016, Freddy's co-founder Bill Simon died at the age of 61 after a battle with cancer. Freddy Simon died at the age of 95 on October 25, 2020. In March 2021, private equity firm Thompson Street Capital Partner purchased Freddy's Frozen Custard & Steakburgers for an undisclosed amount.
Carole Ann Bewley is an American chemist. She is a senior investigator and Chief of the Laboratory of Bioorganic Chemistry at the United States National Institute of Diabetes and Digestive and Kidney Diseases. Bewley researches secondary metabolites and basic principles involved in protein-carbohydrate interactions and how these can be exploited to engineer therapeutics.
Sources: en.wikipedia.org
{\displaystyle {\underbrace {\ce {H-\!\!{\overset {\displaystyle R1 \atop |}{\underset {| \atop \displaystyle R2}{N}}}\!\!\!\!:}} _{\text{amine}}+\underbrace {\ce {R3-{\overset {\displaystyle O \atop \|}{C}}-OH}} _{\text{carboxylic acid}}->}\ \underbrace {\ce {{H-{\overset {\displaystyle R1 \atop |}{\underset {| \atop \displaystyle R2}{N+}}}-H}+R3-COO^{-}}} _{{\text{substituted-ammonium}} \atop {\text{carboxylate salt}}}{\ce {->[{\text{heat}}][{\text{dehydration}}]}}{\underbrace {\ce {{\overset {\displaystyle R1 \atop |}{\underset {| \atop \displaystyle R2}{N}}}\!\!-{\overset {\displaystyle O \atop \|}{C}}-R3}} _{\text{amide}}+\underbrace {\ce {H2O}} _{\text{water}}}}
Reagan was supported by the UK, but opposed by other European allies, who argued it contravened international law. In Operation El Dorado Canyon, orchestrated on 15 April 1986, US military planes launched air-strikes, bombing military installations, killing around 100 Libyans, including civilians. One target had been Gaddafi's home. Himself unharmed, two of Gaddafi's sons were injured, and he claimed his adopted daughter Hanna was killed, although her existence has since been questioned. Gaddafi retreated to the desert to meditate. There were sporadic clashes between Gaddafists and army officers who wanted to overthrow the government. Although the US was condemned internationally, Reagan received a popularity boost at home. Publicly lambasting US imperialism, Gaddafi's reputation as an anti-imperialist was strengthened domestically and across the Arab world, and, in June 1986, he ordered the names of the months to be changed in Libya.
=== Biomolecular research === Researchers often use heterologous expression techniques to study protein interactions. For example, bacteria has been optimized in the heterologous expression and biosynthesis of nitrogenase through NifEN. This is able to be expressed and engineered in E.coli. Through this host, it remains exceedingly challenging to heterologously express a complex, heteromultimeric metalloprotein like NifEN with a full complement of subunits, metalloclusters, and functionality. The NifEN variant engineered in this bacterial host can retain its cofactor efficacy at analogous cofactors-binding sites, which provide proof for heterologous expression and encourage future investigation of this metalloenzyme. Additionally, there have been recent reports of the utility of new filamentous fungal systems in the production of industrial proteins. Advantages include high transformation frequencies, the production of proteins at neutral pH, low viscosity of the fermentation broth due to strain selection for a nonfilamentous format and short fermentation times. Many human gene products, such as albumin, IgG, and interleukin 6, have been expressed in heterologous systems with varying degrees of success. Inconsistent results have hinted at a shift from gene-by-gene studies to a whole-organism approach to post-translational modification. Oocytes are readily optimized for their large size and translational capacity, which is able to observe integrated cell responses.
10 Ca(OH)2 + 6 H3PO4 → Ca10(PO4)6(OH)2 + 18 H2O The ability to synthetically replicate hydroxyapatite has invaluable clinical implications, especially in dentistry. Each technique yields hydroxyapatite crystals of varied characteristics, such as size and shape. These variations have a marked effect on the biological and mechanical properties of the compound, and therefore these hydroxyapatite products have different clinical uses.
Some longitudinal incisions of 2mm of depth have to be made through the skin to proceed to the extraction of latex, which can be collected in solid form some minutes after the extraction. The proteases present in the latex of the fruit are inactive precursors that are activated once the papaya is wounded. In 0.3 ml of latex there are about 15 mg of chymopapain. If we want to conserve the proteolytic properties, latex has to be preserved with sodium metabisulfite and stored at a low temperature of about -10 °C. If used immediately after the incisions, a buffer is added to extract the proteins: EDTA, ammonium sulfate or phosphate buffer all with a concentration of 0.5 mM and a pH of 7. It is also important to block the thiol functions to avoid air oxidation and the loss of proteolytic activity. To eliminate organic and insoluble molecules, the sample is first filtered and afterwards centrifuged at 11000g for 30min. The pellet is discarded and the supernatant added to 96% alcohol with a ratio of 1:3. Impurities precipitate and can be eliminated by filtration. Afterwards, (NH4)2SO4 fractioning is done by addition of this substance at a concentration of 0.472 mg/ml. Chymopapain precipitates and can be retrieved through another centrifugation, again at 11000g for 30min. The supernatant is discarded and the ion exchange chromatography can be carried out, with a linear gradient of 100mM (Na+) and different volumes of elution. Studying A280 chymopapain is found in the fraction of 750-1000 ml.
Sources: en.wikipedia.org
The two share the same 29-amino-acid backbone. CJC-1295 carries an additional albumin-binding moiety that markedly extends its residence time in circulation, while the form without that moiety clears faster. Literature sometimes applies the name loosely to either variant.
It has not been approved by major regulatory agencies for any therapeutic indication. Material sold under this name is typically distributed for laboratory research only. Clinical use is not supported by large controlled trials.
Early human studies of the albumin-binding form reported circulation half-lives on the order of several days. The value depends on assay method and study design. Estimates for the form without the binding moiety are considerably shorter.
The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.