Clinical Significance:
Neurokinin A is a ten amino acid putative transmitter synthesized in the neurons it is present in. Neurokinin A is a member of the family called Tachykinins which also include Neurokinin B, Substance P, Physalaemin, and Eledoisin. Neurokinin A shares 6 of 10 peptide homologies with Neurokinin B even though they are produced by different genes. Neurokinin A is also very similar in structure to Substance P and produces some of the same biological actions as Substance P. Neurokinin A is a potent bronchoconstrictor. In the gut, Neurokinin A is produced by the intrinsic enteric nervous system.
Reference Range:
Up to 40 pg/ml
Procedure:
Neurokinin A is measured by direct radioimmunoassay.
Patient Preparation:
Patient should not be on any medications that affect hypertension, gastrointestinal functions, or pain relievers, if possible, for at least 48 hours prior to collection of specimen.
Specimen Collection:
Collect 10mL blood directly into ISI’s Z-tubeTM Preservative and separate as soon as possible. Freeze plasma immediately after separation. Special Z-tubeTM Preservatives are available from ISI. Minimum specimen size is 1mL.
Note: one Z-tubeTM may be shared for up to three tests. After centrifuging the tube, aliquot 1mL per test in separate vials, mark with name of test and freeze.
Important Precaution:
Specimens for this assay must be collected using the Z-tube. Specimens must be shipped frozen; specimens are not stable at refrigerated or room temperatures. No other specimens are acceptable.
Special Specimens:
For tumor/tissue and various fluids (i.e. CSF, peritoneal, synovial, etc.) contact the Institute for requirements and special handling.
Shipping Instructions:
Ship specimens frozen in dry ice.
References:
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4. Nawa H, Kotani H, Nakanishi S. Tissue specific generation of tissue pre-pro-tachykinin mRNAs from one gene by alternative RNA splicing. Nature. 1984-5;312(5996):729-34
5. Theodorsson-Norheim E, Norheim I, et alG. Neuropeptide K: a major tachykinin in plasma and tumor tissues from carcinoid patients. Biochem Biophys Res Commun. 1985;131(1):77-83.
6. Conlon JM, Deacon CF, Richter G, et al. Measurement and partial characterization of the multiple forms of neurokinin A-like immunoreactivity in carcinoid tumours. Regul Pept. 1986;Jan;13(2):183-96.
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