Measurement of angiotensin II: use of two injectors to minimize HPLC shadowing.
We investigated the use of two HPLC injectors, one reserved for standards and the other for blanks or biological samples, to minimize shadowing in the measurement of angiotensin II (ANGII). HPLC carryover of standard ANGII to blank with a one-injector and a two-injector system were 47.0 +/- 5.0 and 2.4 +/- 0.5 fmol/ml, respectively, a 19.6-fold reduction. Measured normal canine left ventricular myocardium ANGII level by the two-injector HPLC-RIA system was 22.3 +/- 2.4 fmol/g, with a signal-to-noise ratio of 11.7, an improved signal-to-noise ratio of 29.3 fold vs. the one injector. This innovation reduced the incidence of false-positive ANGII results, and thus can be applied to other compounds that exhibit HPLC-derived shadowing.
Division of Cardiology, St. Michael's Hospital, Toronto, Canada.
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Naik
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Forster
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Armstrong
D000804:Angiotensin II / Q000032:analysis* / Q000302:isolation & purification / Q000592:standards; D000809:Angiotensins / Q000302:isolation & purification; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D004285:Dogs; D008297:Male; D009206:Myocardium / Q000737:chemistry; D012015:Reference Standards
D000809:Angiotensins; D000804:Angiotensin II