Regulation of soluble insulin-like growth factor II/mannose 6-phosphate receptor in human serum: measurement by enzyme-linked immunosorbent assay.

Abstract

The soluble form of the insulin-like growth factor II/mannose 6-phosphate (IGF-II/M6-P) receptor has been detected in serum from a variety of mammalian species. We report the development of a highly sensitive quantitative human IGF-II/M6-P receptor immunoassay. Antibodies raised to receptor purified from a human hepatoma cell line by phosphomannan affinity chromatography were used to develop a specific enzyme-linked immunosorbent assay. In this assay, the serum level of soluble receptor for healthy adult subjects was 0.70 +/- 0.23 mg/L. We have shown that soluble receptor is developmentally regulated, with levels in infant (1.12 +/- 0.28 mg/L) and prepubertal (1.18 +/- 0.6 mg/L) subjects dropping by 40% during adolescence (0.73 +/- 0.61 mg/L) and remaining constant throughout adulthood. Further, the receptor is gestationally regulated, with a highly significant association between gestational age and maternal serum receptor levels (r = 0.947; P < 0.0001). Noninsulin-dependent diabetes mellitus (0.98 +/- 0.25 mg/L) and insulin-dependent diabetes mellitus (0.98 +/- 0.25 mg/L) mildly elevated soluble receptor levels, whereas end-stage renal failure (0.75 +/- 0.23 mg/L) and acromegaly (0.79 +/- 0.25 mg/L) did not affect receptor levels. Additionally, we have shown that soluble receptor is present in amniotic fluid, but at a 100-fold lower concentration than serum levels. The ability to quantitate soluble IGF-II/M6-P receptor levels in serum and other fluids provides a valuable tool that will help to further elucidate the role of the receptor in human physiology and disease states.

• Authors: M Costello, R C Baxter, C D Scott
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 84 Issue 2 Pg. 611-7 (Feb 1999) ISSN: 0021-972X [Print] United States
• PMID: 10022425 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptor, IGF Type 2

Topics

• Acromegaly (blood)
• Adolescent
• Adult
• Amniotic Fluid (chemistry)
• Carcinoma, Hepatocellular
• Child
• Diabetes Mellitus, Type 1 (blood)
• Diabetes Mellitus, Type 2 (blood)
• Enzyme-Linked Immunosorbent Assay
• Female
• Gestational Age
• Humans
• Infant
• Kidney Failure, Chronic (blood)
• Liver Neoplasms
• Middle Aged
• Pregnancy
• Receptor, IGF Type 2 (analysis, blood)
• Reference Values
• Tumor Cells, Cultured