The short version of ICP-MS fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-08-19. Anything still debated is marked as such rather than presented as settled.
The sequence now called GHK was first reported in the early 1970s after isolation from human plasma, where it was noted to influence liver cell behavior in laboratory preparations. Later work described a copper-binding form and its activity in fibroblast and wound-model experiments. Review articles frequently group the substance with other copper peptides. Concentrations in blood appear to fall with age in several small surveys, although the reason for this trend is not settled. Whether such a decline carries functional consequences remains an open question.
Published work on GHK-Cu concentrates largely on cell culture systems rather than whole organisms. Frequently used endpoints include collagen synthesis, expression of matrix metalloproteinases, and migration of fibroblasts. Some reports describe antioxidant behavior, while others stress delivery of copper into cells. These mechanisms are proposed rather than demonstrated, and the relative weight of each pathway is unclear. Human trials are few and generally small, so laboratory findings should not be read as confirmed clinical results.
Published work on GHK-Cu is dominated by in vitro experiments and small animal studies. Human trials tend to be short and small, with endpoints such as skin appearance rather than clinical outcomes. Review articles often summarize the same underlying laboratory findings, which can make the evidence base look broader than it is. Several basic questions remain open: the concentration of the intact complex in human tissue, the route by which it crosses the skin barrier, and whether effects seen in culture produce measurable changes in people.
Laboratory studies describe GHK-Cu as a source of copper that cells can take up, with reported effects on collagen, elastin, and glycosaminoglycan synthesis in cultured fibroblasts. The peptide also appears in wound-repair research, where it is linked to the activity of matrix metalloproteinases and their inhibitors. These observations come largely from cell and animal models. How directly the complex controls any single pathway in intact human skin remains an open question, and reported effects depend on concentration, vehicle, and exposure time.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Copper(II) peptide complex | Peptide chain coordinated to a single metal ion |
| CAS number | 89030-95-5 | Indexed for the peptide-copper complex |
| Molecular formula | C14H22CuN6O4 | Approximate formula for a one-to-one complex |
| Appearance | Blue to violet solid | Color from copper d-d transitions |
| Solubility class | Freely soluble in water | Also dispersible in some polar solvents |
Routine characterisation relies on reversed-phase high-performance liquid chromatography for peptide purity, paired with mass spectrometry for identity confirmation. Ultraviolet-visible spectroscopy detects the metal centre through its absorption band in the visible region, and inductively coupled plasma mass spectrometry quantifies total copper so that a metal-to-peptide ratio can be calculated. Amino acid analysis confirms the expected residue composition. Together these techniques establish concentration, identity, and stoichiometry, but none of them directly reports biological activity.
Quality specifications for research material commonly state peptide purity, copper stoichiometry, counter-ion identity, and residual water content. Frequent counter-ions include acetate and trifluoroacetate, which differ in mass and in their effect on solubility and handling. Whether batch-to-batch differences in reported responses trace to these parameters or to assay conditions remains an open question, since published comparisons rarely control for all of them at once. Independent verification therefore normally pairs a purity measurement with an elemental copper measurement on the same lot.
GHK-Cu is a coordination complex formed between the peptide glycyl-L-histidyl-L-lysine and a copper(II) ion. The unbound chain, abbreviated GHK, consists of three amino acids and occurs naturally in human plasma, saliva, and urine. Binding of the metal is mediated mainly by the imidazole nitrogen of the histidine residue together with backbone amides, producing a stable chelate. Ingredient nomenclature often lists the same substance as copper tripeptide-1. Its charge and solubility behaviour differ from those of the metal-free chain.
The copper-binding activity of this sequence was described in the 1970s during studies of liver tissue and plasma factors. Early work identified the peptide as a component that influenced copper uptake by cells and that appeared in wound fluid. Later investigations examined its presence across species, reporting the same chain in human and animal samples. A decline in measured concentration with age became a recurring observation, although the underlying causes remain incompletely characterised.
Copper peptide solutions tend to resist degradation better than many free peptides, because the bound metal protects the N-terminus and reduces susceptibility to some peptidases. Backbone hydrolysis, oxidation of the histidine imidazole ring, and photochemical reactions remain the principal degradation routes. Aqueous solutions are generally most stable near neutral to mildly acidic pH, while strongly alkaline conditions accelerate hydrolysis. Light exposure is usually avoided, since both the peptide and the copper center can take part in photochemical processes. Stability data published by suppliers often describe short-term behavior rather than multi-year shelf life.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, frequently paired with mass spectrometry to confirm the molecular ion. Copper content is measured separately, typically by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy, because the chromatographic signal reports the peptide rather than the metal. Ultraviolet-visible spectroscopy provides a fast check on complex formation, since copper(II) peptide complexes absorb in the visible region. Elemental analysis and amino acid analysis are used less often but remain useful for reference standards. A gap between reported peptide purity and measured copper content is a recurring source of confusion.
Material described as GHK-Cu appears in several distinct markets, including cosmetic ingredients, laboratory reagents, and consumer products, and the quality expectations attached to each differ. A certificate of analysis generally reports peptide purity by chromatography, copper content, appearance, and residual solvents or counterions. Counterion identity matters, because the complex is usually supplied as an acetate or a similar salt, and the counterion contributes to the measured mass. Independent verification of sequence and metal stoichiometry is advisable when a material is used for quantitative work. Batch-to-batch variation is common and should be documented rather than assumed negligible.
In the process, he found that a precipitation of thorium A (polonium-216) and thorium B (lead-212) also contained a short-lived "element", which he named thorium C (which was later identified as polonium-212). Hahn was unable to separate it, and concluded that it had a very short half-life (it is about 300 ns). He also identified radioactinium (thorium-227) and radium D (later identified as lead-210). Rutherford remarked that: "Hahn has a special nose for discovering new elements."
=== Weaning === During weaning, decreased prolactin, missing mechanical stimulation (baby suckling), and changes in osmotic balance caused by milk stasis and leaking of tight junctions cause cessation of milk production. It is the (passive) process of a child or animal ceasing to be dependent on the mother for nourishment. In some species there is complete or partial involution of alveolar structures after weaning, in humans there is only partial involution and the level of involution in humans appears to be highly individual. The glands in the breast do secrete fluid also in nonlactating women. In some other species (such as cows), all alveoli and secretory duct structures collapse by programmed cell death (apoptosis) and autophagy for lack of growth promoting factors either from the ECM or circulating hormones. At the same time, apoptosis of blood capillary endothelial cells speeds up the regression of lactation ductal beds. Shrinkage of the mammary duct tree and ECM remodeling by various proteinase is under the control of somatostatin and other growth inhibiting hormones and local factors. This major structural change leads loose fat tissue to fill the empty space afterward. But a functional lactiferous duct tree can be formed again when a female is pregnant again.
=== Media and arts representation of sickle cell disease === Popular media and art have been important educational tools about sickle cell disease. Hertz Nazaire was a Haitian-American visual artist, writer, and advocate who lived with sickle cell disease and used his art to raise awareness, combat stigma, and champion better access to care. Representations of sickle cell disease in television shows include in the longrunning American medical drama ER (season 4 "Obstruction of Justice" and season 15 "Separation Anxiety" and "Dream Runner"), the 2024 British superhero series Supacell, in the 2024 period drama Lady in the Lake, and in the 2025 medical procedural drama The Pitt (episode "8:00 am"). Noah Wyle, who plays Dr. Michael "Robby" Robinavitch on The Pitt, has spoken about the importance of popular media representation of sickle cell and the impacts of racism on the quality of care patients receive. Sickle cell disease has also been featured in several movies including the 1973 Sydney Poitier classic, A Warm December, 1996 Nigerian drama Mortal Inheritance, Genie Award- winning 2008 Canadian drama Nurse.Fighter.Boy, the 2017 animated documentary Spilled Milk, the 2020 Nigerian drama Strain, the 2022 animated short The Park Bench, and the 2023 American sci-fi action film Transformers: Rise of the Beasts.
The existence of anthropomorphic images and half-human, half-animal images in the Upper Paleolithic may further indicate that Upper Paleolithic humans were the first people to believe in a pantheon of gods or supernatural beings, though such images may instead indicate shamanistic practices similar to those of contemporary tribal societies. The earliest known undisputed burial of a shaman (and by extension the earliest undisputed evidence of shamans and shamanic practices) dates back to the early Upper Paleolithic era (c. 30,000 BP) in what is now the Czech Republic. However, during the early Upper Paleolithic it was probably more common for all members of the band to participate equally and fully in religious ceremonies, in contrast to the religious traditions of later periods when religious authorities and part-time ritual specialists such as shamans, priests and medicine men were relatively common and integral to religious life. Religion was possibly apotropaic; specifically, it may have involved sympathetic magic. The Venus figurines, which are abundant in the Upper Paleolithic archaeological record, provide an example of possible Paleolithic sympathetic magic, as they may have been used for ensuring success in hunting and to bring about fertility of the land and women. The Upper Paleolithic Venus figurines have sometimes been explained as depictions of an earth goddess similar to Gaia, or as representations of a goddess who is the ruler or mother of the animals.
=== Refresh frequency limits for HDR video === Color depth of 10 bpc (30 bit/px or 1.07 billion colors) is assumed for all formats in these tables. This color depth is a requirement for various common HDR standards, such as HDR10. It requires 25% more bandwidth than standard 8 bpc video. HDR extensions were defined in version 1.4 of the DisplayPort standard. Some displays support these HDR extensions, but may only implement HBR2 transmission mode if the extra bandwidth of HBR3 is unnecessary (for example, on 4K 60 Hz HDR displays). Since there is no definition of what constitutes a "DisplayPort 1.4" device, some manufacturers may choose to label these as "DP 1.2" devices despite their support for DP 1.4 HDR extensions. As a result, DisplayPort "version numbers" should not be used as an indicator of HDR support.
Sources: en.wikipedia.org
=== Other uses === Dihydroergocryptine can also be used in migraine prophylaxis, as well as for the treatment of low blood pressure in elderly patients and peripheral vascular disorder. More commonly, it is used in combination with two similar compounds, dihydroergocornine and dihydroergocristine. This mixture is called ergoloid or codergocrine.
Engorgement is the swelling and stretching of the breast tissue due to the accumulation of fluid in the tissue surrounding and supporting the milk-producing cells and ducts. Engorgement most frequently occurs as milk "comes in" and during the weaning process. As milk is coming in, several processes occur. At the end of pregnancy, the blood vessels that supply the breast dilate, allowing for leaking into the tissue or interstitial space. Additionally, the birth of an infant is followed by massive fluid shifts to both offload excess fluid, which had been used to supply oxygen and nutrients to the fetus through the placenta, which is no longer needed, and supply additional fluid to the breasts to start the process of making milk. These fluid shifts often result in some of this excess fluid leaking into the breast tissue. Finally, milk "coming in" can create an uncomfortably full feeling, which, combined with the aforementioned fluid accumulation in the breast tissue, can cause severe pain. If breastfeeding is suddenly stopped, the breasts are likely to become engorged. Pumping small amounts to relieve discomfort helps to train the breasts to produce less milk gradually. There is presently no safe medication to prevent engorgement, but cold compresses and ibuprofen may help to relieve pain and swelling. Pain should go away with emptying of the breasts. If symptoms persist and comfort measures are not helpful, a blocked milk duct or infection may be present, and the affected person should seek medical intervention.
== Early life == Arsène Charles Ernest Wenger was born on 22 October 1949 in Strasbourg, Bas-Rhin, the youngest of three children born to Alphonse and Louise Wenger. He lived in Duppigheim during the 1950s, but spent most of his time in the neighbouring village of Duttlenheim, 16 km (10 miles) south-west of Strasbourg. Arsène's father, Alphonse, like many Alsatians, was conscripted into the German Army by force following Germany's earlier annexation of the French region of Alsace-Lorraine. He was sent to fight on the Eastern Front in October 1944, at the age of 24. The Wenger family owned an automobile spare parts business and a bistro named La Croix d'Or. In his book, My Life in Red and White, Wenger says the "alcohol, brawling and violence" of the bistro's patrons sparked his early interest in human psychology. His parents had difficulty looking after their children, but Duttlenheim was a village where everyone took care of the young; Wenger compared it in later years to a kibbutz. Before Wenger started school, he expressed himself in the local Alsatian dialect of Low Alemannic German. The primary school which Wenger attended was run by the Catholic Church, and as one of its brightest students, he later was accepted into a secondary school in Obernai. According to his father, who also managed the village team, Wenger was introduced to football "at about the age of six". He was taken to games in Germany, where he held an affection for Borussia Mönchengladbach.
Nixtamalization ( nish-tə-mə-lih-ZAY-shən) is a process for the preparation of maize (corn), or other grain, in which the grain is soaked and cooked in an alkaline solution, usually limewater (but sometimes aqueous alkali metal carbonates), washed, and then hulled. The term can also refer to the removal via an alkali process of the pericarp from other grains such as sorghum. Nixtamalized corn has several benefits over unprocessed grain: It is more easily ground, its nutritional value is increased, flavor and aroma are improved, and mycotoxins are reduced by up to 97–100% (for aflatoxins). Lime and ash are highly alkaline: the alkalinity helps the dissolution of hemicellulose, the major glue-like component of the maize cell walls, and loosens the hulls from the kernels and softens the maize. The tryptophan in corn proteins is made more available for human absorption, thus helping to prevent niacin deficiency (pellagra). Tryptophan is the metabolic precursor of endogenous niacin (Vitamin B3). Some of the corn oil is broken down into emulsifying agents (monoglycerides and diglycerides), while bonding of the maize proteins to each other is also facilitated. The divalent calcium in lime acts as a cross-linking agent for protein and polysaccharide acidic side chains. While cornmeal made from untreated ground maize is unable by itself to form a dough on addition of water, nixtamalized cornmeal will form a dough, called masa.
Sources: en.wikipedia.org
It is the copper complex of the tripeptide glycyl-L-histidyl-lysine. The metal ion is held by the histidine imidazole group and the peptide N-terminus. Most research on it concerns skin and wound models.
The tripeptide was first isolated from human plasma and has also been reported in saliva and urine. Plasma levels appear to decline with age in some small studies. Those observations rest on limited sample sizes.
It is not authorized as a systemic medicine in most countries. Cosmetic preparations list it as an ingredient rather than an active pharmaceutical substance. Legal status therefore differs by jurisdiction.
It is not approved as a pharmaceutical in major markets and is used mainly as a cosmetic ingredient and a laboratory reagent. Regulatory status varies by country and by the product category in which it appears. Claims about therapeutic effects should be treated separately from permitted cosmetic labeling.