A PROGRESS REPORT OF INVESTIGATIONS CONCERNED WITH THE EXPERIMENTAL TREATMENT OF HYPERTENSION WITH KIDNEY EXTRACTS

Abstract

Improvement in preparation of kidney extracts has been made in that local and general reactions have been much reduced in number and severity. The yield of active material remains low. An in vitro assay method depending upon the ability of kidney extract to destroy angiotonin has been devised. There is suggestive evidence that a direct relationship exists between antipressor activity and ability to destroy angiotonin, but this has not been proved. Two enzymes which destroy angiotonin (angiotonase) are contained in kidneys, one with optimal activity at about pH 4.0 and the other at about pH 7.5. The latter enzyme appears abundantly in the more active antipressor extracts.