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Test-Category
ELISA
Pack size
96 Tests
Standard concentrations included in the kit
1.1-33 µg/l
Possible sample matrix and volumes
| Plasma | 20 µl |
| Serum | 20 µl |
| Urine | 100 µl |
Incubation periods
Indications
Regulatory Status
Retinol binding Protein (RBP) is small (21kD) transport protein for vitamin A which forms a complex with pre-albumin in blood but looses its affinity for prealbumin once the vitamin has been deliverd to the target cells. The free RBP molecule is rapidly filtered at the glomerulus and catabolized in the renal tubules after resorption by the proximal tubular cells (like other samll molecules e.g. ß-2 Microglobulin). In kidney disease with prevailing tubular changes these proteins are not reabsorbed and appear in the urine.
As actually published by Yang et al. (Nature [2005] 436: 356-362) the plasma form of the RBP, RBP4, seems to play a key role in the development of insulin resistence. The fat cell derived peptide RBP4 which contributes to the transport of vitamin A into the circulatory system for subsequent use also modulates the glucose homeostasis and impairs the insulin sensitivity / insulin resistence. The elevation of serum RBP4 causes systemic insulin resistance, and the reduction of serum RBP4 improves insulin action.
Our RBP ELISA determines the free RBP4 form as well as complex bound RBP4 (RBP4 - prealbumin complex).
