Abstract
Although various chromogenic substrates have been developed for determination of proteases, there are few reports on the determination of glandular kallikrein (GK) in tissues using chromogenic substrates.
The authors have determined GK of the rat stomach by measuring its esterolytic activity on Pro-Phe-Arg-NE (PPA-NE) which is one of the naphthylester derivatives.
The extracted rat stomach was kept frozen for one week; then thawed, homogenized, and ultracentrifuged for sixty minutes at 105, 000G.
The supernatant was used as specimens and examined for the existence of contaminative proteases. The results showed that their amounts were so small that their effects on determining the activity of GK were negligible.
The authors determined the esterolytic activity of the specimen on PPA-NE and also the amount of kallidin produced from low molecular weight kininogen acted by the specimen, and studied correlation between the values of two measurments. The correlation coefficient for these two variables was:
r=0.953 [y=10.354x+0.051]
This high correlation implies that GK of the rat stomach can be estimated by its esterolytic activity on PPA-NE.
