Melanocyte Stimulating Hormone, Alpha (a-MSH)

Clinical Significance:
a-Melanocyte Stimulating Hormone is a 13 amino acid peptide produced from metabolism of Proopiomelanocortin.  One of the fragments of Proopiomelano-cortin is Adrenocorticotropin which is further fragmented to form a-Melanocyte Stimulating Hormone and Corticotropin-Like Intermediate Lobe Peptide (CLIP).  The major biological property of a-Melanocyte Stimulating Hormone is hyper-pigmentation.  It also stimulates Aldosterone secretion, alters the blood-brain barrier permeability for glucose, sucrose and albumin, and is excreted by the placenta.  Levels are higher in children dropping to adult levels as activity of the intermediate lobe of the pituitary declines.  a-Melanocyte Stimulating Hormone is the major melanotropin in the rat corresponding to b-Melanocyte Stimulating Hormone in the human.

Reference Ranges:
Adults:                            Up to 5.0 pg/ml

a-Melanocyte Stimulating Hormone is measured by direct radioimmunoassay.

Patient Preparation:
Patient should not be on any Steroid, ACTH, or hypertension medication, if possible, for at least 48 hours prior to collection of specimen.  Morning, fasting specimens are preferred; non-fasting specimens are acceptable.

Specimen Collection:
3mL EDTA plasma should be collected and separated as soon as possible. Freeze specimen immediately after separation. Minimum specimen size is 1mL. Serum is no longer accepted for ISI’s assay.

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.

1. DB Seifer and RL Collins.  Current Concepts of b-Endorphin Physiology in Female Reproductive Dysfunction.  Clinical Chemistry 54: 757-771, 1990.

2. M Shapiro, WE Nicholson, DN Orth, WM Mitchell, and GW Liddle.  Differences between Ectopic MSH and Pituitary MSH.  Journal of Clinical Endocrinology and Metabolism 33: 377, 1971.