Human platelet fraction arginine-vasopressin: potential physiological role

• Published in: The Journal of clinical investigation Vol. 79; no. 3; pp. 881 - 887
• Main Authors: BICHET, D. G, ARTHUS, M.-F, BARJON, J. N, LONERGAN, M, KORTAS, C
• Format: Journal Article
• Language: English
• Published: Ann Arbor, MI American Society for Clinical Investigation 01-03-1987
• Subjects: Adult; Arginine Vasopressin - blood; Biological and medical sciences; Blood; Blood Platelets - metabolism; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Diabetes Insipidus - blood; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Osmolar Concentration; Receptors, Angiotensin - metabolism; Receptors, Vasopressin; Sodium Chloride; Vertebrates: blood, hematopoietic organs, reticuloendothelial system; Water; Human; Biological fixation; Platelet; Immunoreactive form; Osmolarity; 8-Arginine vasopressin; Peptide hormone; HPLC chromatography; In vitro
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/jci112898

Arginine-vasopressin (AVP) immunoreactivity (Ir) has been found to be elevated in platelet-rich plasma. PlatAVP was defined as platelet-rich plasma Ir minus platelet-poor plasma Ir (Pavp). PlatAVP, Pavp, and synthetic AVP were found to have identical retention time on high performance liquid chromatography analysis and similar mobility on thin-layer chromatography. During a standard osmotic suppression-stimulation test, Pavp increased with plasma osmolality (Posm, mosmol/kg H2O); Pavp (pg/ml) = 0.98 (Posm -274.4), r = 0.57, P less than 0.001, n = 65; but PlatAVP was not significantly correlated with Posm and remained at 5 pg/ml. This PlatAVP concentration was estimated to represent a true intraplatelet AVP concentration of 0.4 to 3.7 X 10(-9) M. Binding studies on intact human platelets demonstrated specific binding sites for [3H]AVP (n = 16; BMax = 98 +/- 30 binding sites/platelet; Kd = 0.72 +/- 0.24 nM). This in vitro affinity association constant (Kd) was close to the estimated in vivo intraplatelet AVP concentration. Measurement of PlatAVP could estimate vasopressin bound to a specific platelet receptor.