SIMULTANEOUS MEASUREMENT OF CATECHOLAMINES AND KALLIKREIN IN URINE USING BORIC-ACID PRESERVATIVE

Catecholamines, dopamine and the renal kallikrein-kinin system may par ticipate in the pathogenesis of hypertension. In the past these system s have been studied independently in isolation. Attempts to study the systems together have been hampered by incompatibility of the current urine preservatives for the two assays involved. In order to measure a cid-stable catecholamines and acid-labile kallikrein enzyme together, we have established boric acid solution as a preservative by comparing the stability of urinary catecholamines stored in it with the commonl y employed preservative, hydrochloric acid (HCl) as well as the stabil ity of urinary kallikrein in untreated urine with and without boric ac id at ambient temperatures for 24 and 48 h, and at - 20 degrees C for 2 weeks and 1, 2 and 3 months. The stability of other common urine par ameters including cortisol, electrolytes, creatinine and protein, was also investigated after storage with boric acid at ambient temperature for 24 h. Our results showed that there was a good agreement between the measurements of urinary catecholamines stored in both HCl and bori c acid and that the latter did not interfere with measurements of urin ary kallikrein or other common urine parameters. (C) 1998 Elsevier Sci ence B.V. All rights reserved.