Abstract
1) Evidence that renin is one of lysosomal enzymes was found. Among the subcellular fractions from the kidney and the liver, kidney lysosomal fraction almost exclusively had a non-dialyzable pressor substance. This was released from the particles by repeated freezing and thawing, and its reaction product with plasma was a heat-stable material which demonstrated a pressor effect with the characteristics of angiotensin. 2) The proportion of acid ATPase and acid phosphatase in the lysosomes of the kidney was different from that of the liver. Acid ATP-ase seemed to be released by freezing and thawing faster than acid phosphatase. The possible occurrence of acid ATPase distinct from acid phosphatase is discussed.
