Simultaneous determination of angiotensins II and 1-7 by capillary zone electrophoresis in plasma and urine from hypertensive rats.

We describe the procedure developed for the simultaneous detection and quantification of angiotensin II and angiotensin-(1-7), by capillary zone electrophoresis with UV detection by photodiode-array, at a wavelength of 200 nm, in the plasma and urine from hypertensive rats. Optimal separation was achieved with a 100mM boric acid+3mM tartaric acid+10 fM gold (III) chloride electrolyte solution at pH 9.80. The applied voltage was 30 kV and the capillary temperature was kept constant at 20 degrees C. The method was over the concentration range of 0.01-500 pmol/mL. All determination coefficients were higher or equal to 0.9985. Limits of detection and quantification for angiotensin II were 0.0110 pmol/mL (S/N=3) and 0.0195 pmol/mL (S/N=5), respectively. While for angiotensin-(1-7), the limits were 0.0112 pmol/mL (S/N=3) and 0.0193 pmol/mL (S/N=5), respectively. The present method offers a time-saving way to simultaneous determination of angiotensin II and angiotensin-(1-7), since it can be completed in 10 min, compared to other methodologies reported in the literature for capillary electrophoresis and liquid chromatography, which require more than 1h for analysis of complex matrices, such as plasma and urine. The procedure is illustrated by experiments that quantify simultaneously angiotensin II and angiotensin-(1-7) in plasma and urine from hypertensive and normotensive rats, with and without antihypertensive treatment. The levels of angiotensin II and angiotensin-(1-7) detected in the experimental model, resulted in a recovery of 99.00-106.01% and a reproducibility of less than 10%. The proposed analytical method is a use full tool for the simultaneous detection of angiotensin II and angiotensin-(1-7) implicated in vascular remodeling in pathologies such as hypertension.