title: A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood.
abstract: Research in the field of food intake regulation is gaining importance. This often includes the measurement of peptides regulating food intake. For the correct determination of a peptide's concentration, it should be stable during blood processing. However, this is not the case for several peptides which are quickly degraded by endogenous peptidases. Recently, we developed a blood processing method employing Reduced temperatures, Acidification, Protease inhibition, Isotopic exogenous controls and Dilution (RAPID) for the use in rats. Here, we have established this technique for the use in humans and investigated recovery, molecular form and circulating concentration of food intake regulatory hormones. The RAPID method significantly improved the recovery for (125)I-labeled somatostatin-28 (+39%), glucagon-like peptide-1 (+35%), acyl ghrelin and glucagon (+32%), insulin and kisspeptin (+29%), nesfatin-1 (+28%), leptin (+21%) and peptide YY3-36 (+19%) compared to standard processing (EDTA blood on ice, p <0.001). High performance liquid chromatography showed the elution of endogenous acyl ghrelin at the expected position after RAPID processing, while after standard processing 62% of acyl ghrelin were degraded resulting in an earlier peak likely representing desacyl ghrelin. After RAPID processing the acyl/desacyl ghrelin ratio in blood of normal weight subjects was 1:3 compared to 1:23 following standard processing (p = 0.03). Also endogenous kisspeptin levels were higher after RAPID compared to standard processing (+99%, p = 0.02). The RAPID blood processing method can be used in humans, yields higher peptide levels and allows for assessment of the correct molecular form.
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin.
authors.forename: Pauline
authors.initials: P
authors.lastname: Teuffel
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin; Department of Internal Medicine, Institute of Neurogastroenterology and Motility, Martin-Luther Hospital, Academic Teaching Institution of Charité Universitätsmedizin Berlin.
authors.forename: Miriam
authors.initials: M
authors.lastname: Goebel-Stengel
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hofmann
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin.
authors.forename: Philip
authors.initials: P
authors.lastname: Prinz
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin.
authors.forename: Sophie
authors.initials: S
authors.lastname: Scharner
authors.affiliation: Department of Hepatology and Gastroenterology, Molecular Cancer Research Center (MKFZ), Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Körner
authors.affiliation: Department of Hepatology and Gastroenterology, Molecular Cancer Research Center (MKFZ), Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin.
authors.forename: Carsten
authors.initials: C
authors.lastname: Grötzinger
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rose
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin.
authors.forename: Burghard F
authors.initials: BF
authors.lastname: Klapp
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division General Internal and Psychosomatic Medicine, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin; andreas.stengel@charite.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stengel
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004435:Eating; D005934:Glucagon; D006801:Humans; D007328:Insulin; D020738:Leptin; D051381:Rats
chemical_list: D001798:Blood Proteins; D007328:Insulin; D020738:Leptin; D005934:Glucagon