The choice of conditions for cathepsin D activity determination in human saliva.

The aim of the study was the demonstration and choice of conditions for the determination of cathepsin D activity in human mixed saliva. The 6% solution of hemoglobin, denatured with hydrochloric acid, was used as the substrate. The ratio of saliva volume to hemoglobin was 4:1 w/v. The reaction was interrupted by adding 10% trichloroacetic acid, after 6 hours of incubation at 37 degrees C. The increase in degradation products was determined with the use of Folina and Ciocalteau method with copper modification.