The short version of GHRH receptor fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-07-02. Anything still debated is marked as such rather than presented as settled.
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
At the pituitary, the peptide binds the growth hormone-releasing hormone receptor on somatotroph cells. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone. Somatostatin and other hypothalamic signals modulate this response. Negative feedback from insulin-like growth factor 1 also influences output. The same regulatory architecture operates with the native hormone. Whether the synthetic analog alters feedback dynamics over repeated exposure remains an open question. Most published receptor work uses cell models rather than intact human systems.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
| Property | Value | Notes |
|---|---|---|
| Molecular weight, DAC form | About 3647 Da | Varies with salt form |
| Molecular weight, non-DAC form | About 3358 Da | MOD GRF(1-29) |
| Solubility class | Water soluble | Also dissolves in polar solvents |
| Reported half-life, DAC form | About five to eight days | Values from human studies |
| Common synonyms | CJC-1295; MOD GRF(1-29) | Name depends on variant |
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
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.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
Laboratory handling centers on minimizing exposure to water, heat and oxygen before use. Working solutions are typically prepared in sterile water or a mild buffer, and any residual particulate matter is removed by filtration. When the powder dissolves slowly, a small proportion of acetonitrile or dilute acetic acid is sometimes added as a co-solvent. Containers are kept sealed and desiccated between uses. Records of lot number, reconstitution date and storage conditions support later comparison of results across experiments.
== History == Lamivudine/zidovudine (brand name Combivir) was introduced to the market with FDA approval in 1997. Its impact in history is significant as it was the first combination therapy with a fixed dose for HIV-positive people, and soon solidified its title as a gold standard as it was the most prescribed NRTI in initial HIV treatment for newly diagnosed patients. The arrival of Combivir was seen as a new revolution in HIV therapy, with its improved toxicity profile and tolerability, especially compared to the undesirable side effects of lone AZT therapy or the unfavorable facial and lipoatrophy seen in Stavudine monotherapy at that time.
In animals and humans, orexin receptor agonists such as orexin-A and danavorexton dose-dependently produce wakefulness and locomotor activity while orexin receptor antagonists like suvorexant transiently reduce locomotor activity and dose-dependently promote sleep. Acute orexin receptor antagonists can promote sleep in animals to a greater extent than what occurs in narcolepsy-like orexin system loss. In addition, little to no cataplexy has been observed even with high doses of orexin receptor antagonists in animals and humans. It is unknown if long-term use of orexin receptor antagonists may produce compensatory neural changes or narcolepsy-like symptoms. An animal study of chronic high-dose suvorexant administration that showed development of narcolepsy-like changes suggests that this may be possible however. Endogenous orexinergic tone is expected to play an important moderating influence in terms of the effects of orexin receptor modulators. As an example, rising orexin levels during the day may help to competitively offset the next-day residual effects of nightly-dosed orexin receptor antagonists.
== History == Cellulose was discovered in 1838 by the French chemist Anselme Payen, who isolated it from plant matter and determined its chemical formula. Cellulose was used to produce the first successful thermoplastic polymer, celluloid, by Hyatt Manufacturing Company in 1870. Production of rayon ("artificial silk") from cellulose began in the 1890s and cellophane was invented in 1912. Hermann Staudinger determined the polymer structure of cellulose in 1920. The compound was first chemically synthesized (without the use of any biologically derived enzymes) in 1992, by Kobayashi and Shoda.
Sources: en.wikipedia.org
=== From alkenes === Disubstituted alkenes react with HCN in the presence of strong acids to give formamides, which can be decarbonylated. This method, the Ritter reaction, is used industrially to produce tertiary amines such as tert-octylamine. Hydroamination of alkenes is also widely practiced. The reaction is catalyzed by zeolite-based solid acids.
Following the September 11 attacks, SPME was used to test for toxins in the air at Ground Zero at the World Trade Center. In 2008, Pawliszyn was honoured for his invention of SPME with the EnCana Principal Award as someone who has made a significant impact in the world outside the lab. He also earned the American Chemical Society's Separations Science and Technology Award. In March 2010, Pawliszyn was promoted to the rank of University Professor of Chemistry at the University of Waterloo. A few months later, he was recognized for "innovation leadership" as part of the Ontario Premier's Innovation Awards for 2010. Through the same year, Pawliszyn was elected a Fellow of the Royal Society of Canada for "developing state-of-the-art, integrated and automated analytical methods and instruments for on-site analysis and monitoring of living and environmental systems." Upon becoming a fellow, Pawliszyn received the 2011 Dal Nogare award from the Chromatography Forum of Delaware Valley as a scientist who has made a significant contribution in the field of chromatography. The following year, Pawliszyn was honoured by the Canadian Society for Chemistry with the 2012 E.W.R. Steacie Award as a scientist who has made a "distinguished contribution to chemistry while working in Canada." In 2019, Pawliszyn was ranked the 9th most influential person in analytical science across the globe by Analytical Scientist. He also received the 2019 Talanta Medal for his numerous contributions to analytical chemistry and for his pioneering work in SPME.
=== Insulin-like growth factors === Insulin-like growth factors (IGF) assist bone growth in the body. IGF's are single-chain polypeptides that are similarly structured to insulin. There are 2 IGFs: Insulin-like growth factor 1 (IGF-1), and Insulin-like growth factor 2 (IGF-2). IGF-1 is induced by growth hormone (GH), and targets cartilage, stimulating cell bone cell proliferation. Studies carried out by Yakar S, Rosen CJ have shown in animal models that IGF-1 can enhance longitudinal growth, periosteal circumference, and bone mineral density. IGF-1 is responsible for increasing overall body size, longitudinal bone size, and height, especially during puberty.
Sources: en.wikipedia.org
=== Political changes === The revolution brought Romania vast attention from the outside world. Initially, much of the world's sympathy went to the FSN government under Ion Iliescu, a former member of the CPR leadership and a Ceaușescu ally prior to falling into the dictator's disfavour in the early 1980s. The FSN, composed mainly of former members of the second echelon of the CPR, immediately assumed control over the state institutions, including the main media outlets such as the national radio and television networks. They used their control of the media to launch attacks against their political opponents, newly created political parties that claimed to be successors to those existing before 1948. Around the same time, all Romanian numbers stations ceased transmitting, including a number station called "Ciocârlia/The Skylark", also known as "V01" after the revolution. Much of that sympathy was squandered during the Mineriads. Massive protests erupted in downtown Bucharest as political rallies organised by the opposition parties during the presidential elections, with a small part of the protesters deciding to stand ground even after Iliescu was re-elected with an overwhelming majority of 85%. Attempts by police to evacuate the remaining protesters resulted in attacks on state institutions, prompting Iliescu to appeal to the country's workers for help. Infiltrated and instigated by former Securitate agents, in the following days a large mass of workers, mainly miners, entered Bucharest and attacked and fought with anti-government protesters and gathered bystanders.
A firm can design any number of channels they require to reach customers efficiently and effectively. Channels can be distinguished by the number of intermediaries between producer and consumer. If there are no intermediaries then this is known as a zero-level distribution system or direct marketing. A level one (sometimes called one-tier) channel has a single intermediary. A level two (alternatively a two-tier) channel has two intermediaries, and so on. This flow is typically represented as being manufacturer to retailer to consumer, but may involve other types of intermediaries. In practice, distribution systems for perishable goods tend to be shorter - direct or single intermediary, because of the need to reduce the time a product spends in transit or in storage. In other cases, distribution systems can become quite complex involving many levels and different types of intermediaries.
=== Civilian === Although the majority of the world's submarines are military, there are some civilian submarines, which are used for tourism, exploration, oil and gas platform inspections, and pipeline surveys. Some are also used in illegal activities. The Submarine Voyage ride opened at Disneyland in 1959, but although it ran under water, it was not a true submarine, as it ran on tracks and was open to the atmosphere. The first tourist submarine was Auguste Piccard, which went into service in 1964 at Expo64. By 1997, there were 45 tourist submarines operating around the world. Submarines with a crush depth in the range of 400–500 feet (120–150 m) are operated in several areas worldwide, typically with bottom depths around 100 to 120 feet (30 to 37 m), with a carrying capacity of 50 to 100 passengers. In a typical operation a surface vessel carries passengers to an offshore operating area and loads them into the submarine. The submarine then visits underwater points of interest such as natural or artificial reef structures. To surface safely without danger of collision the location of the submarine is marked with an air release and movement to the surface is coordinated by an observer in a support craft. A recent development is the deployment of so-called narco-submarines by South American drug smugglers to evade law enforcement detection. Although they occasionally deploy true submarines, most are self-propelled semi-submersibles, where a portion of the craft remains above water at all times.
In both pharmacology and nutrition sciences, bioavailability is measured by calculating the area under curve (AUC) of the drug concentration time profile. Bioavailability is a term used to describe the percentage of an administered dose of a xenobiotic that reaches the systemic circulation unchanged. It is denoted by the letter f (or, if expressed in percent, by F). In nutritional science, which covers the intake of nutrients and non-drug dietary ingredients, the concept of bioavailability lacks the well-defined standards associated with the pharmaceutical industry. The pharmacological definition cannot apply to these substances because utilization and absorption is a function of the nutritional status and physiological state of the subject, resulting in even greater differences from individual to individual (inter-individual variation). Therefore, bioavailability for dietary supplements can be defined as the proportion of the administered substance capable of being absorbed and available for use or storage.
Sources: en.wikipedia.org
It is a synthetic peptide modeled on growth hormone-releasing hormone. The molecule is used in research on pituitary growth hormone secretion. It differs from the natural hormone through several stabilizing substitutions.
The DAC form carries a maleimide group that binds albumin and extends circulation time. The non-DAC form lacks this group and clears much faster. Both share the same receptor-binding core.
It targets the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Activation raises cyclic AMP and promotes growth hormone release. Normal feedback pathways remain part of the response.
The synthetic peptide keeps the receptor-binding region of GHRH but carries substitutions that resist enzymatic cleavage. In the DAC version, an added group also anchors the molecule to albumin, extending its presence in the bloodstream.