A commercial kit for plasma renin activity (PRA) (Sorin Biomedica, Saluggia, Italy) has been examined as to its reliability for using it in clinical and experimental research. The following aspects were examined: temperature: plasma processing at room temperature (25°C) or in the cold (4°C), prior to RIA, did not affect final PRA values, provided that cold treatment of plasma is employed after pH adjustment to 5.7 by adding a mixture of angiotensinases inhibitors (BAL and 8-OH-quinoline); plasma dilution: the latter has been tested (from 1:0.1 to 1:4) adding a mixture of angiotensinases inhibitors; a dilution of 1:1, as suggested in the kit instructions, appears to be acceptable for high and normal PRA plasmas, while dilutions over this range did interfere with PRA levels, particularly as far as low renin plasma samples are concerned; angiotensinase inhibitor concentration: BAL 0.99 mg/ml and 8-OH-quinoline 1.32 mg/ml allowed a complete inhibition of angiotensinases similar to that observed using PMSF from 0.5 to 0.75 mg/ml; protein concentration: no significant variations in PRA have been observed by varying the proteins concentration of the phosphate buffer from 0.1 g/100 ml, as suggested in the kit instructions, to 1.6 g/100 ml; specificity of the antiserum: a very high specificity of the commercial antiserum has been detected, since its cross reactivity with Angiotensin II, Angiotensin III and tetradecapeptide was very low: 0.30 ± 0.25% and 0.28 ± 0.24% and 0.55 ± 0.27% respectively, assuming as 100% the reactivity of the antiserum for angiotensin I. Taken together, these data are consistent with a good reliability of using the SORIN kit for PRA, not only for routine determinations but also for employing it in clinical and/or experimental research.
|Title of host publication||Journal of Nuclear Medicine and Allied Sciences|
|Number of pages||5|
|Publication status||Published - 1985|
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