03.02.17.01 Diagnostika / Kits für die Tumormarker-Bestimmung
Diagnostika / Kits für die Tumormarker-Bestimmung
Produktkategorie: Biogene Amine
KYNURENINE ELISA ivd/CE
The essential amino acid tryptophan is a constituent of proteins and is also a substrate for two important biosynthetic pathways: the generation of the neurotransmitter serotonin (5-hydroxytryptamine) and the formation of nicotinamide adenine dinucleotides via different kynurenine derivatives. L-kynurenine is formed in the mammalian brain (40%) and is taken up from the periphery (60%), indicating that it can be transported across the blood-brain-barrier. It can be converted by the inducible enzyme indoleamine 2,3-dioxygenase (IDO) into two other important compounds: the neuroprotective kynurenic acid and the neurotoxic quinolinic acid. The kynurenine pathway is also closely linked to the immune system, as different cytokines do influence the activity of the key enzymes. An unbalanced tryptophan-kynurenine pathway is associated with different kind of diseases such as mental and psychotic disorders (e.g. depressions; Alzheimer´s disease; Huntington´s chorea), stress, and inflammatory neurological diseases (amyotrophic lateral sclerosis; ALS).
LDN has developed an Enzyme-Linked Immunosorbent Assay (ELISA) which is useful for measuring kynurenine levels under different healthy and pathological conditions.
Cells derived form neuroendocrine tumours (e.g. pheochromcytoma) are known to produce catecholamines which are secreted episodically via vesicles into the bloodstream. But beside this a small portion of the catecholamines is metabolized inside the cells to the corresponding catecholamines metabolites – namely metanephrine, normetanephrine and 3-methoxytyramine (3-MT) – which are secreted at low levels continuously into the bloodstream. 3-methoxytyramine is a metabolite of the neurotransmitter Dopamine formed by the introduction of a methyl group to dopamine by the enzyme catechol-O-methyl transferase (COMT). The measurement of 3-MT allows the detection of dopamine-producing tumours: For example a substantial number of patients with head-and-neck paragangliomas (HNPGL) have biochemically active tumors and only display increased excretion of 3-methoxytyramine, but not of other catecholamines or their metabolites.
The combined levels of free metanephrine/normetanephrine and free 3-MT in plasma indicate a higher number of biochemically active HNPGLs than the 24-h urinary excretion rates of these markers.
In addition 3-MT acts as a neuromodulator and can also induce behavioral effects involved in movement control in a dopamine-independent manner. Most of these effects are mediated by the trace amine associated receptor 1 (TAAR1) which in turn is involved in abnormal dopaminergic transmission, such as Parkinson's disease, dyskinesia and schizophrenia.
Histamine Assays - the most comprehensive panel worldwide
- BA E-1000 Histamine in Urine, plasma, and Whole Blood - BA E-5800 Histamine Research* - BA E-1700 Histamine in Cell Culture, whole blood, AND URINE - BA E-1100 Histamine Release - FC E-3100 Histamine in Food - FC E-3600 Histamine in Fish - FC P-3000 HisQuick - Test for Fish meal - FC L-3200 HistaSure - Dispstick Test for Histamine IN FISH AND FISH MEAL * for any biological fluid
The determination of normetanephrine and metanephrine in plasma is a sensitive test for diagnosing phaechromocytoma and paragangliomas (PPGLs) – but it does not provide the possibility to detect dopamine-producing tumours. Dopamine and especially its O-methylated metabolite 3-MT are reliable biomarkers for the detection of malignant PPGLs.
The new 3-methoxytyramine RIA compares with excellence to the LC-MS/MS method (please refer to the flyer attached) and offers an accurate, selective and sensitive measurement of 3-MT.
The assay itself uses an elegant extraction procedure followed by a competitive RIA.
With this new assay LDN is now able to offer the most comprehensive panel worldwide for the measurement of PPGL-relevant parameters including:
· Urinary Metanephrine/Normetanephrine (free and total; ELISA&RIA)
· Plasma Metanephrine/Normetanephrine (ELISA&RIA)
· Catecholamines in plasma and urine (ELISA&RIA)
· Chromogranin A (ELISA)
· and – closing the diagnostic gap – 3-Methoxytyramine (RIA)