Altered Urinary Kallikrein Excretion in Rats with Hypertension
The urinary excretion of kallikrein, an enzyme which cleaves a vasodilator kinin from kininogen substrate, was examined in three types of hypertensive rats. Enzyme activity was measured by both esterase activity (isotopic assay) and bioassay with purified rat urinary kallikrein as a standard. Excretion of kallikrein was found to increase with age in spontaneously hypertensive rats, but levels were lower and stable in normotensive Wistar control animals. Rats with desoxycorticosterone-salt hypertension excreted markedly more, whereas rats with renal hypertension excreted significantly less kallikrein than did control animals. The alterations in kallikrein excretion were unrelated to changes in urine volume and protein excretion. The findings indicate that the kallikrein-kinin system may be involved in different forms of hypertension in the rat.
- spontaneous hypertension
- renal hypertension
- desoxycorticosterone-salt hypertension
- urinary protein
- kallikrein bioassay
- kallikrein esterase activity (isotopic assay)
- Received October 15, 1971.
- Accepted December 29, 1971.
- © 1972 American Heart Association, Inc.