title: Extraction of oxytocin and arginine-vasopressin from serum and plasma for radioimmunoassay and surface-enhanced laser desorption-ionization time-of-flight mass spectrometry.
abstract: Oxytocin and arginine-vasopressin (AVP) are secreted into the blood in low concentrations. To analyze these peptides, we investigated two common extraction procedures, acetone-ether precipitation and C(18)-SepPak columns. Recovery from both procedures approached 70-80% of the spiked amount, though the SepPak columns were more efficient. C(18)-SepPak columns were used to sequentially separate oxytocin from AVP by eluting oxytocin first with 98% acetone followed by elution of AVP with 80% acetonitrile. Surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF MS) was used to analyze oxytocin and AVP extracted with C(18)-SepPak columns from an autistic patient's plasma sample. We conclude that C(18)-SepPaks provide more consistent and efficient peptide extraction from serum or plasma that augments both quantitative and qualitative analysis by radioimmunoassay and SELDI-TOF MS.
authors.affiliation: Department of Pharmacology and Toxicology, Wright State University, 3640 Colonel Glenn Hwy., PO Box 927, Dayton, OH 45435, USA. david.cool@wright.edu
authors.forename: David R
authors.initials: DR
authors.lastname: Cool
authors.forename: David
authors.initials: D
authors.lastname: DeBrosse
mesh_terms: D001127:Arginine Vasopressin / Q000097:blood / Q000302:isolation & purification*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D010121:Oxytocin / Q000097:blood / Q000302:isolation & purification*; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D001127:Arginine Vasopressin; D010121:Oxytocin