Tissue distribution of calcium-activated neutral proteinases in rat.

A simple separation method involving a minimum number of essential steps was established to separate the two kinds of calcium-activated neutral proteinase (CANP) activity from each other and from endogenous CANP inhibitor activity. Determination of CANP activity in rat tissues using this method revealed a ubiquitous distribution of two CANPs. The level of CANP activity, however, differs between tissues. Low-calcium-requiring CANP (microCANP) is plentiful in spleen and kidney, while high-calcium-requiring CANP (mCANP) is plentiful in lung and brain. In all of the tissues examined, mCANP activity predominates over microCANP activity.