KCL-EXTRACTED PLASMINOGEN ACTIVATOR IN KIDNEY OF RABBITS.

1. The extraction with hypertonic solution of KCI, KI, or sucrose showed a fairly high activity of plasminogen activator of the kidney parenchyma, while the KSCN extract of the kidney parenchyma failed to demonstrate the activity in rabbits.2. The activator extracted from frozen kidney showed stronger activity than that from the fresh tissue.3. The activator activity of kidney parenchyma was completely inhibited, when EACA or AMCHA was added to the standard fibrin plate.4. KCl-extracted activator of the kidney parenchyma of rabbit was rather stable at pH 7, despite of its lability at acid reaction.5. A rather higher activity of the activator was demonstrated with KSCN-extract than with KCl- or sucrose-extract from the kidney pelvis.6. From rat kidney two kinds of extracts were obtained concerned with pH stability; KSCN-extract was acid stable but destroyed at pH 7, KCl-extract was acid labile but showed rather high activity at pH 7, after heating for 30 minutes at 37°C.