title: Determination of the levels of novel 31-amino acid endothelins and endothelins in human lungs.
abstract: An effective method for determination of the levels of newly discovered 31-amino acid endothelins [ETs(1-31)] as well as big ETs and 21-amino acid ETs [ETs(1-21)], in human lungs has been developed. About 85% of ETs in human lung homogenates were recovered on acid extraction 8 times. Most of the published protocols for the determination of tissue ETs involve a reverse-phase minicolumn to separate proteins from peptides, after which the levels of ETs are directly determined by enzyme immunoassay. The levels determined, however, include fairly high amounts of non-bioactive ET metabolites in tissues and the data reported are diverse. We established an effective methods for the extraction and the separation of nine different muscle constricting ETs from their metabolites on a reverse-phase C18 column. Using this protocol, the levels of ETs in human lungs were determined by means of a sandwich-enzyme immunoassay specific for each ET derivative. The levels of ET-2(1-21) were the highest among those of ETs, and the levels of ETs(1-31) were in a similar range to those of big ETs but were lower than those of ETs(1-21). This method can be utilized to assess the pathophysiological roles of ETs(1-31) in various human organs.
authors.affiliation: Department of Pharmacology, School of Medicine, Institute for Enzyme Research, The University of Tokushima, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Okishima
authors.forename: M
authors.initials: M
authors.lastname: Yoshizumi
authors.forename: K
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: P
authors.initials: P
authors.lastname: Cui
authors.forename: H
authors.initials: H
authors.lastname: Kitamura
authors.forename: T
authors.initials: T
authors.lastname: Tamaki
authors.forename: H
authors.initials: H
authors.lastname: Kido
mesh_terms: D002851:Chromatography, High Pressure Liquid; D019332:Endothelin-1 / Q000031:analogs & derivatives; D016232:Endothelins / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008168:Lung / Q000737:chemistry*; D010446:Peptide Fragments / Q000032:analysis*
chemical_list: D019332:Endothelin-1; D016232:Endothelins; D010446:Peptide Fragments; C114932:endothelin-1 (1-31)