Simplified method for quantitation of angiotensin peptides in tissue.
A simple method for extraction, separation, identification and quantitation of angiotensin-like immunoactivity from tissue is described. Homogenized acetic acid extracts of tissue samples were lyophilized and reconstituted in mobile phase. Separation was performed by reversed-phase high-performance liquid chromatography on a phenyl silica gel column with an eluent consisting of 20% acetonitrile in 0.1 M aqueous ammonium phosphate buffer, pH 4.9. Elution of standard peptides under isocratic conditions revealed clear resolution of angiotensin I, II and III and the (1-7) and (3-8) peptides. Recoveries of labeled angiotensin peptide standards from the extraction step were > 90%. Radioimmunoassay of relevant peaks revealed detectable levels of angiotensin I-, II- and III-like immunoactivity in single rat hypothalami and brain stems.
Meng
Q C
QC
Department of Medicine, University of Alabama, Birmingham 35294-0007.
Durand
J
J
Chen
Y F
YF
Oparil
S
S
D000803:Angiotensin I / Q000032:analysis*; D000804:Angiotensin II / Q000032:analysis*; D000818:Animals; D001933:Brain Stem / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007031:Hypothalamus / Q000737:chemistry; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley
D000804:Angiotensin II; D000803:Angiotensin I