Clinical Significance:
Neuropeptide Y is a 36 amino acid peptide very similar throughout all species of mammals. It is found primarily in the sympathetic nervous system, gut, and brain. Neuropeptide Y is closely related structurally to Peptide YY and Vasoactive Intestinal Polypeptide. Neuropeptide Y has key roles in cardiovascular and hypothalamic function. It potentiates vasoconstriction, causing an increase in blood pressure. Levels are increased by stress, Dexamethasone, septic shock, relaxation of colon, Atrial Natriuretic Factor, water and sodium secretion, Luteinizing Hormone and ACTH. Levels are inhibited by amphetamines, and are decreased in patients with Alzheimer’s disease. Neuropeptide Y inhibits Norepinephrine, the effect of Cholecystokinin, Renin release, Insulin and Glucagon secretion, and the Melanotropins. Actions of Neuropeptide Y are enhanced by a2 adrenoreceptor agonists.
Reference Range:
By report.
Procedure:
Neuropeptide Y is measured by direct radioimmunoassay.
Patient Preparation:
Patient should be fasting 10 – 12 hours prior to collection of specimen. Medications that affect Insulin secretion or gastrointestinal function should be discontinued, if possible, for at least 48 hours prior to collection
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-tube (is available from Inter Science Institute (ISI). Minimum specimen size is 1 ml.
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:
1. H Jamal, PM Jones, J Byrne, K Suda, MA Ghatei, SM Kanse, and SR Bloom. Peptide Contents of NeuropeptideY, Vasoactive Intestinal Polypeptide, and b-Calcitonin Gene-Related Peptide and Their Messenger Ribonucleic Acids after Dexamethasone Treatment in the Isolated Rat Islets of Langerhans. Endocrinology 129: 3372-3380, 1991.
2. J Lehmann. Neuropeptide Y: An Overview. Drug Development Research 19: 329-351, 1989.