Abstract
Two types of radioimmunoassay (RIA) methods for measuring endothelin (ET) in human plasma were developed. One was an extraction procedure using a Sep-Pak C18 cartridge, the other being a direct method. By the extraction method, plasma ET levels were lower than the detectable limit (7 pg/ml) in normal subjects and elevated in hemodialysis patients. The absolute values obtained via the direct method were 20-times higher than those from extraction. Gel-filtration experiments revealed that this discrepancy was mainly due to immunoreactive (IR-) endothelin-like substances of high molecular mass near 11.6 kDa (large IR-ET). Extraction of the peptide by the C18 cartridge could eliminate interference by large IR-ET and is important in the accurate measurement of ET concentrations in plasma.
Original language | English |
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Pages (from-to) | 239-242 |
Number of pages | 4 |
Journal | FEBS Letters |
Volume | 249 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1989 Jun 5 |
Keywords
- (Human plasma)
- Endothelin
- Hemodialysis
- Immunoreactivity
- Radioimmunoassay
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology