Domoic acid
Encyclopedia
Domoic acid the neurotoxin that causes amnesic shellfish poisoning
(ASP), also known as zombie acid, is a kainic acid
analog, heterocyclic amino acid
associated with certain harmful algal blooms.
. "Doumoi" is used as an anthelmintic
in Tokunoshima, Kagoshima
. Domoic acid is also produced by diatom
s of the genus Pseudo-nitzschia
and the species Nitzschia navis-varingica.
Pseudo-nitzschia multiseries loses most of its ability to produce domoic acid when it is cultured axenically. However, domoic acid production recovers when bacteria from the original culture are reintroduced to axenic
cultures, indicating a bacterial association with domoic acid production in this species.
The increasing frequency and geographic extent of toxic algal blooms along populated coastlines is generally attributed to human activities.
and proline
.
s of the Pacific Ocean
.
Domoic acid can bioaccumulate
in marine
organisms such as shellfish
, anchovies
, and sardine
s that feed on the phytoplankton
known to produce this toxin. DA can accumulate in high concentrations in the tissues of these plankton feeders when the toxic phytoplankton itself is high in concentration in the surrounding waters.
In mammal
s, including human
s, domoic acid acts as a neurotoxin
, causing short-term memory
loss, brain damage
and, in severe cases, death
. DA-producing algal bloom
s are associated with the phenomenon of amnesic shellfish poisoning
(ASP). In marine mammals, domoic acid typically causes seizures and tremors. In the brain, domoic acid especially damages the hippocampus
and amygdaloid nucleus. It damages the neuron
s by activating AMPA
and kainate receptors, causing an influx of calcium
. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate. Because the hippocampus may be severely damaged, short-term memory loss occurs.
Amnesic shellfish poisoning
Amnesic shellfish poisoning is a human illness caused by consumption of the marine biotoxin called domoic acid. This toxin is produced naturally by marine diatoms belonging to the genus Pseudo-nitzschia and the species...
(ASP), also known as zombie acid, is a kainic acid
Kainic acid
Kainic acid is a natural marine acid present in some seaweed. It is a specific agonist for the kainate receptor used as an ionotropic glutamate receptor which mimics the effect of glutamate...
analog, heterocyclic amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
associated with certain harmful algal blooms.
Occurrence
In 1958, domoic acid was originally isolated from the red alga called "doumoi" or "hanayanagi" (Chondria armata) in JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. "Doumoi" is used as an anthelmintic
Anthelmintic
Anthelmintics or antihelminthics are drugs that expel parasitic worms from the body, by either stunning or killing them. They may also be called vermifuges or vermicides .-Pharmaceutical classes:...
in Tokunoshima, Kagoshima
Tokunoshima, Kagoshima
left|thumb|Kametoku Port in the town. is a town in Ōshima District, Kagoshima, Japan. It is located on the island of Tokunoshima.As of 2008, it has an estimated population of 12,656 and the density of 121 persons per km²...
. Domoic acid is also produced by diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s of the genus Pseudo-nitzschia
Pseudo-nitzschia
The genus Pseudo-nitzschia includes several species of diatoms known to produce the neurotoxin known as domoic acid, a toxin which is responsible for the human illness called amnesic shellfish poisoning...
and the species Nitzschia navis-varingica.
Pseudo-nitzschia multiseries loses most of its ability to produce domoic acid when it is cultured axenically. However, domoic acid production recovers when bacteria from the original culture are reintroduced to axenic
Axenic
In biology, axenic describes a culture of an organism that is entirely free of all other "contaminating" organisms. The earliest axenic cultures were of bacteria or unicellular eukaryotes, but axenic cultures of many multicellular organisms are also possible...
cultures, indicating a bacterial association with domoic acid production in this species.
The increasing frequency and geographic extent of toxic algal blooms along populated coastlines is generally attributed to human activities.
Chemistry
Domoic acid is a structural analog of kainic acidKainic acid
Kainic acid is a natural marine acid present in some seaweed. It is a specific agonist for the kainate receptor used as an ionotropic glutamate receptor which mimics the effect of glutamate...
and proline
Proline
Proline is an α-amino acid, one of the twenty DNA-encoded amino acids. Its codons are CCU, CCC, CCA, and CCG. It is not an essential amino acid, which means that the human body can synthesize it. It is unique among the 20 protein-forming amino acids in that the α-amino group is secondary...
.
Toxicology
Considerable recent research has been carried out by the Marine Mammal Center and other scientific centers on the association of domoic acid-producing harmful algal blooms and neurological damage in marine mammalMarine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
s of the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
.
Domoic acid can bioaccumulate
Bioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
in marine
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
organisms such as shellfish
Shellfish
Shellfish is a culinary and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some kinds are found only in freshwater...
, anchovies
Anchovy
Anchovies are a family of small, common salt-water forage fish. There are 144 species in 17 genera, found in the Atlantic, Indian, and Pacific Oceans. Anchovies are usually classified as an oily fish.-Description:...
, and sardine
Sardine
Sardines, or pilchards, are several types of small, oily fish related to herrings, family Clupeidae. Sardines are named after the Mediterranean island of Sardinia, around which they were once abundant....
s that feed on the phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
known to produce this toxin. DA can accumulate in high concentrations in the tissues of these plankton feeders when the toxic phytoplankton itself is high in concentration in the surrounding waters.
In mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, including human
Human
Humans are the only living species in the Homo genus...
s, domoic acid acts as a neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
, causing short-term memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
loss, brain damage
Brain damage
"Brain damage" or "brain injury" is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors...
and, in severe cases, death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
. DA-producing algal bloom
Algal bloom
An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration...
s are associated with the phenomenon of amnesic shellfish poisoning
Amnesic shellfish poisoning
Amnesic shellfish poisoning is a human illness caused by consumption of the marine biotoxin called domoic acid. This toxin is produced naturally by marine diatoms belonging to the genus Pseudo-nitzschia and the species...
(ASP). In marine mammals, domoic acid typically causes seizures and tremors. In the brain, domoic acid especially damages the hippocampus
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
and amygdaloid nucleus. It damages the neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s by activating AMPA
AMPA
AMPA is a compound that is a specific agonist for the AMPA receptor, where it mimics the effects of the neurotransmitter glutamate....
and kainate receptors, causing an influx of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate. Because the hippocampus may be severely damaged, short-term memory loss occurs.
External links
- Domoic Acid and Pseudo-nitzschia References at Fisheries and Oceans CanadaFisheries and Oceans CanadaFisheries and Oceans Canada, frequently referred to as DFO , is the department within the government of Canada that is responsible for developing and implementing policies and programs in support of Canada's economic, ecological and scientific interests in oceans and inland waters...
- Amnesic Shellfish Poisoning, Domoic Acid, and Pseudo-nitzschia links at the ISSHA website
- Domoic acid at IPCS INCHEM
- DOMOIC ACID - A MAJOR CONCERN TO WASHINGTON STATE’S SHELLFISH LOVERS at Washington Department of Fish and Wildlife