Oxidopamine
Encyclopedia
Oxidopamine, also known as 6-hydroxydopamine (6-OHDA) or 2,4,5-trihydroxyphenethylamine, is a neurotoxin
used by scientists to selectively kill dopaminergic
and noradrenergic neurons. 6-OHDA enters the neurons via the dopamine
and noradrenaline (aka norepinephrine
) reuptake transporters. Oxidopamine is often used in conjunction with a selective noradrenaline reuptake inhibitor (such as desipramine
) to selectively kill dopaminergic neurons only. The reverse is also possible, however it is rarely done in research.
The main use for oxidopamine in scientific research is to induce Parkinsonism
in laboratory animals such as mice, rats and monkeys, in order to develop and test new medicines for treating Parkinson's disease
in humans. In order to induce this condition in animals, around 90% of the dopaminergic neurons in the substantia nigra
of the brain must be destroyed, and this is achieved either with oxidopamine or MPTP
. Both these agents likely destroy neurons by generating active oxygen species such as superoxide
radical. Oxidopamine toxicity in neonatal rodents is also used as an animal model for the Lesch-Nyhan syndrome
.
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...
used by scientists to selectively kill dopaminergic
Dopaminergic
Dopaminergic means related to the neurotransmitter dopamine. For example, certain proteins such as the dopamine transporter , vesicular monoamine transporter 2 , and dopamine receptors can be classified as dopaminergic, and neurons which synthesize or contain dopamine and synapses with dopamine...
and noradrenergic neurons. 6-OHDA enters the neurons via the dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
and noradrenaline (aka norepinephrine
Norepinephrine
Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
) reuptake transporters. Oxidopamine is often used in conjunction with a selective noradrenaline reuptake inhibitor (such as desipramine
Desipramine
Desipramine is a tricyclic antidepressant . It inhibits the reuptake of norepinephrine and to a lesser extent serotonin. It is used to treat depression, but not considered a first line treatment since the introduction of SSRI antidepressants...
) to selectively kill dopaminergic neurons only. The reverse is also possible, however it is rarely done in research.
The main use for oxidopamine in scientific research is to induce Parkinsonism
Parkinsonism
Parkinsonism is a neurological syndrome characterized by tremor, hypokinesia, rigidity, and postural instability. The underlying causes of parkinsonism are numerous, and diagnosis can be complex...
in laboratory animals such as mice, rats and monkeys, in order to develop and test new medicines for treating Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
in humans. In order to induce this condition in animals, around 90% of the dopaminergic neurons in the substantia nigra
Substantia nigra
The substantia nigra is a brain structure located in the mesencephalon that plays an important role in reward, addiction, and movement. Substantia nigra is Latin for "black substance", as parts of the substantia nigra appear darker than neighboring areas due to high levels of melanin in...
of the brain must be destroyed, and this is achieved either with oxidopamine or MPTP
MPTP
MPTP is a neurotoxin precursor to MPP+, which causes permanent symptoms of Parkinson's disease by destroying dopaminergic neurons in the substantia nigra of the brain...
. Both these agents likely destroy neurons by generating active oxygen species such as superoxide
Superoxide
A superoxide, also known by the obsolete name hyperoxide, is a compound that possesses the superoxide anion with the chemical formula O2−. The systematic name of the anion is dioxide. It is important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature...
radical. Oxidopamine toxicity in neonatal rodents is also used as an animal model for the Lesch-Nyhan syndrome
Lesch-Nyhan syndrome
Lesch–Nyhan syndrome , also known as Nyhan's syndrome, Kelley-Seegmiller syndrome and Juvenile gout, is a rare inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase , produced by mutations in the HPRT gene located on X chromosome. LNS affects about...
.