The measurement of the IGFBP-3 concentration is regarded as the best indicator of the Growth Hormone (GH) deficiency due to better stability in serum in comparison to IGF-I. Moreover, IGFBP-3 determinations are highly recommended for monitoring the effectiveness of treatment in case of GH deficiency and acromegaly.
IBL International IGFBP-3 ELISA (MD58031) benefits • Suitable for human serum, EDTA or heparin plasma,
• Only 10 L sample volume: ideal for use in pediatrics,
• Short incubation time: 2.5 h,
• Assay Range: 0.03 - 15.150 ng/mL,
• Very good precision: mean intra-/inter-assay variation: 1.9%/5.7%,
• No cross-reactivity to homologous proteins (IGFBP-1, -2, -4, -5 and -6).
Physiological function In serum, approximately 95% of IGF-I and IGF-II are bound to IGFBP-3, making this protein the main carrier of the circulating insulin-like growth factor. The predominating IGFBP in blood is IGFBP-3, which largely determines the total IGF-I and IGF-II concentration.
In contrast to the other binding proteins, IGFBP-3 has the unique property to associate with an acid-labile non-binding subunit (ALS) after binding of either IGF-I or IGF-II.
Most of the IGFBP-3 in plasma is present as the high molecular weight ternary complex. However, IGF bounded into this complex is biologically inactive.