Copper(II) oxide is an oxide of copper. It occurs naturally as the mineral tenorite. Copper(II) oxide is used as a pigment in ceramics, in the production of rayon, as a dietary supplement, in dry and wet cell batteries, for welding copper alloys, and as a semiconductor. Copper is a chemical element with the symbol Cu and atomic number 29. Copper is an essential elements in plants and animals as it is required for the normal functioning of more than 30 enzymes. It occurs naturally throughout the environment in rocks, soil, water, and air. (4, 5, 8)
belongs to the class of inorganic compounds known as transition metal oxides. These are inorganic compounds containing an oxygen atom of an oxidation state of -2, in which the heaviest atom bonded to the oxygen is a transition metal.
Excess copper is sequestered within hepatocyte lysosomes, where it is complexed with metallothionein. Copper hepatotoxicity is believed to occur when the lysosomes become saturated and copper accumulates in the nucleus, causing nuclear damage. This damage is possibly a result of oxidative damage, including lipid peroxidation. Copper inhibits the sulfhydryl group enzymes such as glucose-6-phosphate 1-dehydrogenase, glutathione reductase, and paraoxonases, which protect the cell from free oxygen radicals. It also influences gene expression and is a co-factor for oxidative enzymes such as cytochrome C oxidase and lysyl oxidase. In addition, the oxidative stress induced by copper is thought to activate acid sphingomyelinase, which lead to the production of ceramide, an apoptotic signal, as well as cause hemolytic anemia. Copper-induced emesis results from stimulation of the vagus nerve. (4, 11, 1, 7)
Metabolism
Copper is mainly absorbed through the gastrointestinal tract, but it can also be inhalated and absorbed dermally. It passes through the basolateral membrane, possibly via regulatory copper transporters, and is transported to the liver and kidney bound to serum albumin. The liver is the critical organ for copper homoeostasis. In the liver and other tissues, copper is stored bound to metallothionein, amino acids, and in association with copper-dependent enzymes, then partitioned for excretion through the bile or incorporation into intra- and extracellular proteins. The transport of copper to the peripheral tissues is accomplished through the plasma attached to serum albumin, ceruloplasmin or low-molecular-weight complexes. Copper may induce the production of metallothionein and ceruloplasmin. The membrane-bound copper transporting adenosine triphosphatase (Cu-ATPase) transports copper ions into and out of cells. Physiologically normal levels of copper in the body are held constant by alterations in the rate and amount of copper absorption, compartmental distribution, and excretion. (4, 6)
No indication of carcinogenicity to humans (not listed by IARC).
Uses/Sources
Copper(II) oxide is used as a pigment in ceramics, in the production of rayon, as a dietary supplement, in dry and wet cell batteries, for welding copper alloys, and as a semiconductor. (8)
People must absorb small amounts of copper every day because copper is essential for good health, however, high levels of copper can be harmful. Very-high doses of copper can cause damage to your liver and kidneys, and can even cause death. Copper may induce allergic responses in sensitive individuals. (5, 6)
Symptoms
Breathing high levels of copper can cause irritation of the nose and throat. Ingesting high levels of copper can cause nausea, vomiting, diarrhea, headache, dizziness, and respiratory difficulty. (5, 6)
Treatment
EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration.
