Copyright ©The Author(s) 2018.
World J Nephrol. Mar 6, 2018; 7(2): 51-57
Published online Mar 6, 2018. doi: 10.5527/wjn.v7.i2.51
Table 1 Distinct production sites of precursor arginine vasopressin in hypothalamus
Site of synthesis in hypothalamusMagnocellular neurons (Supra-optic and paraventricular)Parvocellular neurons
Processing of AVPOccurs during axonal transport in the infundibulum with copeptin and neurophysin acting as chaperones for correct AVP foldingOccurs in the parvocellular neurons where it released with other releasing hormones, such corticotrophin releasing hormone
StoragePosterior pituitaryHypothalamus
Stimuli for releaseOsmotic and haemodynamic stimuli from the posterior pituitary glandReleased in response to humoural stress together with CRH, which both act on the adrenal gland to release cortisol
Table 2 Summary of vasopressin limitations compared to copeptin advantages as a biomarker using the thermo scientific B.R.A.H.M.S KRYPTOR assay (adapted from Thermo Fisher scientific)
FeaturesLimitations of measuring AVPAdvantages of CT-proAVP (Copeptin)
Ex vivo stabilityUnstable (even at -20 °C)Stable at > 3 d at room temperature
Sample volume required400 L50 μL
Time to results3 working daysapproximately 1 h
SensitivityLow (small molecule size, measured only by competitive immunoassay)High (larger size, can be measured using a sensitive sandwich immunoassay)
Measuring range1.15-73.8 pmol/L0.7-500 pmol/L and up to 2000 pmol/L with automated dilution