This is a working overview of GRF(1-29), written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-12-09. Anything still debated is marked as such rather than presented as settled.
The dividing feature between the two forms is a maleimide-based drug affinity complex, abbreviated DAC. In the DAC-bearing version, a linker attaches the peptide to serum albumin after administration, and that association slows removal from plasma. The version lacking DAC appears in catalogs as MOD GRF(1-29) or tetrasubstituted GRF(1-29). Because informal writing treats both as one item, comparisons drawn from such sources routinely blend measurements taken from two molecules with substantially different behavior.
Four amino acid substitutions separate the modified backbone from the parent GRF(1-29) sequence. These changes reduce recognition by dipeptidyl peptidase IV and related proteases, extending the interval before degradation. Development work in this area sought longer-acting GHRH analogs for endocrine investigation. Published descriptions treat the substitution set as a defining property of the core sequence, while the albumin-binding linker is described separately as an optional addition to that same backbone.
CJC-1295 is a synthetic peptide analog of growth hormone-releasing hormone, constructed on the 29-amino-acid fragment designated GRF(1-29). The name began as an internal development code during the 1990s and later spread through research supply catalogs and discussion forums. The molecule does not occur in nature; its sequence is engineered rather than isolated from tissue. Two related compounds are sold under this single label, and they differ by one appended chemical group that strongly influences how long the peptide remains in circulation.
CJC-1295 is a synthetic peptide belonging to the growth hormone-releasing hormone analog family. It comprises twenty-nine amino acid residues derived from the N-terminal region of natural GHRH. The molecule incorporates several non-natural substitutions that increase resistance to enzymatic degradation. These modifications extend its activity compared with the native hormone fragment. Researchers use it to study pituitary growth hormone secretion in laboratory and clinical settings. This compound is distinct from native GHRH in its stability profile.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Analog of growth hormone-releasing hormone |
| Chain length | 29 amino acids | Based on the GRF(1-29) fragment |
| Appearance | White to off-white lyophilized powder | Common research supply form |
| Solubility | Soluble in water and aqueous buffers | Powder requires reconstitution before use |
| Typical storage | −20 °C or below | Kept away from light and moisture |
Lyophilized peptide powder is comparatively stable when kept dry, cold, and protected from light. Once dissolved, the molecule is vulnerable to deamidation, oxidation, and aggregation, with the rate depending on pH, buffer composition, and temperature. Alkaline conditions and repeated freeze-thaw cycles accelerate loss of the intact peptide. The methionine present in the native sequence is a known oxidation site, which is one reason it was replaced in the modified fragment. Suppliers typically recommend cold storage of solutions and use within a short window.
Analytical confirmation usually relies on reversed-phase high-performance liquid chromatography for purity and on liquid chromatography coupled to mass spectrometry for identity. Mass data reveal the expected molecular mass and can flag truncated or oxidized species. Amino acid analysis and peptide mapping provide sequence-level verification. Immunoassays are used in some biological matrices, but antibodies raised against one releasing-hormone analog may cross-react with another. Reported purity figures depend heavily on the method used, so comparisons between suppliers require matching the analytical approach.
The two variants differ dramatically in how long they persist in circulation. The form lacking the albumin-binding group has a plasma half-life measured in tens of minutes, comparable to the natural hormone fragment. The version carrying the drug affinity complex binds albumin and shows a half-life of roughly six to eight days in human studies. That figure comes from small trials that tracked hormone levels over extended periods. The physiological consequences of sustained versus pulsatile stimulation are still debated and the literature does not settle the point.
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.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
Electrospray ionization is the ion source of choice to couple liquid chromatography with mass spectrometry (LC-MS). The analysis can be performed online, by feeding the liquid eluting from the LC column directly to an electrospray, or offline, by collecting fractions to be later analyzed in a classical nanoelectrospray-mass spectrometry setup. Among the numerous operating parameters in ESI-MS, for proteins, the electrospray voltage has been identified as an important parameter to consider in ESI LC/MS gradient elution. The effect of various solvent compositions (such as TFA or ammonium acetate, or supercharging reagents, or derivitizing groups) or spraying conditions on electrospray-LCMS spectra and/or nanoESI-MS spectra. have been studied.
The botched embalming of Pope Pius XII (1876–1958; pope 1939–1958) by a charlatan doctor – which only sped up the rate of decomposition – led to his body turning black and his nose falling off while lying in state, and the body disintegrated in the coffin. The Swiss Guards stationed around Pius XII's body were forced to change shifts every 10 to 15 minutes, since the body's odor caused some guards to pass out. The doctor who performed the embalming had also taken photos of the pontiff in his death throes, intending to sell them to tabloids. The Italian tabloids refused to buy the photos, and the doctor was banned from entering the Vatican City-State by John XXIII, who furthermore prohibited any photography of a deceased pope until the body is properly vested and laid out. Charles XII (1682–1718) is one of several Swedish kings to have been embalmed. When Charles XII's sarcophagus was opened in 1917, his features were still recognizable, almost 200 years after his death. Photographs of his remains clearly show the gunshot wound to his head leading to his death. The body of Pope John XXIII (1881–1963; pope 1958–1963) is on display on an altar on the main floor of the Basilica of Saint Peter after having been exhumed from the grottoes beneath the main altar and has retained an extremely well-preserved state. If a body's remains do not decompose, contrary to expectations, it is often treated as a miracle. However, the case of John XXIII's body did not enjoy the same acclamation, as it was held to have been due to embalming and adipocere formation.
The condition known today as diabetes (usually referring to diabetes mellitus) is thought to have been described in the Ebers Papyrus (c. 1550 BC). Ayurvedic physicians (5th/6th century BC) first noted the sweet taste of diabetic urine, and called the condition madhumeha ("honey urine"). The term diabetes traces back to Demetrius of Apamea (1st century BC). For a long time, the condition was described and treated in traditional Chinese medicine as xiāo kě (消渴; "wasting-thirst"). Physicians of the medieval Islamic world, including Avicenna, have also written on diabetes. Early accounts often referred to diabetes as a disease of the kidneys. In 1674, Thomas Willis suggested that diabetes may be a disease of the blood. Johann Peter Frank is credited with distinguishing diabetes mellitus and diabetes insipidus in 1794. In regard to diabetes mellitus, Joseph von Mering and Oskar Minkowski are commonly credited with the formal discovery (1889) of a role for the pancreas in causing the condition. In 1893, Édouard Laguesse suggested that the islet cells of the pancreas, described as "little heaps of cells" by Paul Langerhans in 1869, might play a regulatory role in digestion. These cells were named islets of Langerhans after the original discoverer. In the beginning of the 20th century, physicians hypothesized that the islets secrete a substance (named "insulin") that metabolises carbohydrates. The first to isolate the extract used, called insulin, was Nicolae Paulescu.
Sources: en.wikipedia.org
== Potential role in vascularization of solid tumors == Elevated FSH receptor levels have been detected in the endothelia of tumor vasculature in a very wide range of solid tumors. FSH binding is thought to upregulate neovascularization via at least two mechanisms – one in the VEGF pathway, and the other VEGF independent – related to the development of umbilical vasculature when physiological. This presents possible use of FSH and FSH-receptor antagonists as an anti-tumor angiogenesis therapy (cf. avastin for current anti-VEGF approaches).
The persistence of apnea can depend on factors such as premedication, dose administered, and rate of administration, and may sometimes persist for longer than 60 seconds. Possibly as the result of depression of the central inspiratory drive, propofol may produce significant decreases in respiratory rate, minute volume, tidal volume, mean inspiratory flow rate, and functional residual capacity. Propofol administration also results in decreased cerebral blood flow, cerebral metabolic oxygen consumption, and intracranial pressure. In addition, propofol may decrease intraocular pressure by as much as 50% in patients with normal intraocular pressure. A more serious but rare side effect is dystonia. Mild myoclonic movements are common, as with other intravenous hypnotic agents. Propofol appears to be safe for use in porphyria, and has not been known to trigger malignant hyperthermia. Propofol is also reported to induce priapism in some individuals, and has been observed to suppress REM sleep and to worsen the poor sleep quality in some patients. Rare side effects include:
M(CO)+n → M(CO)+n−1 + CO Electron ionization is the most common technique for characterizing the neutral metal carbonyls. Neutral metal carbonyls can be converted to charged species by derivatization, which enables the use of electrospray ionization (ESI), instrumentation for which is often widely available. For example, treatment of a metal carbonyl with alkoxide generates an anionic metallaformate that is amenable to analysis by ESI-MS:
==== Canada ==== 5-MAPB is not an explicitly listed controlled substance in the Controlled Drugs and Substances Act in Canada. However, it is an implicitly controlled substance in this country under the act's phenethylamine and amphetamine catch-all clauses, which bans amphetamines as well as phenethylamine benzofurans.
Sources: en.wikipedia.org
=== Common fundamentals === In any form of chromatography, the rate at which the solute moves down the column is a direct reflection of the percentage of time the solute spends in the mobile phase. To achieve separation in either elution or displacement chromatography, there must be appreciable differences in the affinity of the respective solutes for the stationary phase. Both methods rely on movement down the column to amplify the effect of small differences in distribution between the two phases. Distribution between the mobile and stationary phases is described by the binding isotherm, a plot of solute bound to (or partitioned into) the stationary phase as a function of concentration in the mobile phase. The isotherm is often linear, or approximately so, at low concentrations, but commonly curves (concave-downward) at higher concentrations as the stationary phase becomes saturated.
== Biosynthesis == NAAG synthetase activity mediates the biosynthesis of NAAG from glutamate and NAA, but little is known about the mechanism or regulation of this enzyme, and no NAAG synthetase activity has been isolated in cell-free preparations. Since other neuropeptides and nearly all vertebrate peptides are synthesized by post-translational processing, NAAG synthetase activity is relatively unique. As with NAA, the synthesis of NAAG is primarily restricted to neurons, although glial cells also contain and synthesize this peptide. In vitro, NAAG synthesis appears to be regulated by the availability of its precursor, NAA. In addition, during differentiation of neuroblastoma cells, it has been shown that a protein kinase A (PKA) activator will increase the quantity of NAAG, while a protein kinase C (PKC) activator will decrease its concentration. This finding suggests that PKA and PKC have opposing regulatory effects on the NAAG synthetase enzyme.
MDMA is a well-balanced serotonin–norepinephrine–dopamine releasing agent (SNDRA). (R)-MDMA and (S)-MDMA are both SNDRAs similarly. However, (R)-MDMA is several-fold less potent than (S)-MDMA in vitro and is also less potent than (S)-MDMA in vivo in non-human primates. In addition, whereas MDMA and (S)-MDMA are well-balanced SNDRAs, (R)-MDMA is comparatively much less potent as a dopamine releasing agent (~11-fold less potent in releasing dopamine than serotonin), and could be thought of instead more as a serotonin–norepinephrine releasing agent (SNRA) than as an SNDRA. In non-human primates, (S)-MDMA demonstrated significant dopamine transporter (DAT) occupancy, whereas DAT occupancy with (R)-MDMA was undetectable. Similarly, MDMA and (S)-MDMA were found to increase dopamine levels in the striatum in rodents and non-human primates, whereas (R)-MDMA did not increase striatal dopamine levels. As such, (R)-MDMA may be less psychostimulant-like than MDMA or (S)-MDMA. In addition to its actions as an SNDRA, MDMA has weak affinity for the serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptors, where it acts as an agonist. (R)-MDMA shows higher affinity for the serotonin 5-HT2A receptor than (S)-MDMA or MDMA. In addition, (R)-MDMA is more potent as an agonist of the serotonin 5-HT2A receptor, acting as a weak partial agonist of this receptor, whereas (S)-MDMA shows very little effect. Conversely however, (S)-MDMA is more potent as an agonist of the serotonin 5-HT2C receptor. Based on these findings, it has been hypothesized that (R)-MDMA may be more psychedelic-like than (S)-MDMA.
=== Transgenic plant and animals === In recent years, expression vectors have been used to introduce specific genes into plants and animals to produce transgenic organisms, for example in agriculture it is used to produce transgenic plants. Expression vectors have been used to introduce a vitamin A precursor, beta-carotene, into rice plants. This product is called golden rice. This process has also been used to introduce a gene into plants that produces an insecticide, called Bacillus thuringiensis toxin or Bt toxin which reduces the need for farmers to apply insecticides since it is produced by the modified organism. In addition expression vectors are used to extend the ripeness of tomatoes by altering the plant so that it produces less of the chemical that causes the tomatoes to rot. There have been controversies over using expression vectors to modify crops due to the fact that there might be unknown health risks, possibilities of companies patenting certain genetically modified food crops, and ethical concerns. Nevertheless, this technique is still being used and heavily researched. Transgenic animals have also been produced to study animal biochemical processes and human diseases, or used to produce pharmaceuticals and other proteins. They may also be engineered to have advantageous or useful traits. Green fluorescent protein is sometimes used as tags which results in animal that can fluoresce, and this have been exploited commercially to produce the fluorescent GloFish.
When lipids are extracted or isolated from biomembranes, polymorphism and mesomorphism can occur because they are then no longer under the intermolecular constraints that are present within the biomembrane. This can lead to formation of non-lamellar (non-bilayer) or lamellar phases in phospholipids. "Polymorphism" refers to formation of diverse structures such as three-dimensional tubes, rods, and structures with cubic symmetry. Mesomorphism refers to phase transitions when heat is applied. For example, a lipid can be in the lamellar phase at a lower temperature, but as the temperature increases, it transitions into a non-lamellar phase. It is important to consider the size of the hydrophilic region versus the hydrophobic region. For example, if the hydrophilic region and hydrophobic region are similar, a cylindrical shape lipid bilayer is formed; but when the hydrophilic regions is smaller than the hydrophobic region a cone-shaped lipid bilayer is formed. Another example is the formation of micelles which has a non-lamellar formation in which the hydrophilic region is significantly larger compared to the hydrophobic region. There are various liquid-crystalline phases that can exist in lipids. Liquid-crystalline phases are when the hydrophobic chain regions are not motionless but are allowed to move about freely in a fluid-like melted state. The lamellar phase (Lα) is the most common and dominant phase in lipids and are aligned as stacks of bilayers on top of bilayers oriented in one single direction.
Sources: en.wikipedia.org
No. It is a laboratory-synthesized analog built on a fragment of the natural hormone. The natural peptide is shorter-lived and lacks the stabilizing substitutions found in the synthetic version.
DAC stands for drug affinity complex, a chemical group that binds the peptide to serum albumin. The binding slows clearance and lengthens the time the molecule stays in plasma compared with the unmodified analog.
Because two distinct molecules are discussed under one informal label. The albumin-binding version clears over several days, while the form without that group clears within roughly half an hour. Mixing results from both creates inconsistent figures.
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.