Prolidase activity in rat brain; developmental, regional and subcellular distribution.

We determined the regional and subcellular distribution of prolidase in rat brain and its changes with development. The most rapid changes in enzyme activity occurred perinatally, with a maximum level of activity 2 days before birth and a minimum 1 day after birth. Of the 7 regions examined, cerebellum had the highest enzyme level, followed by medulla. The lowest levels were found in the hypothalamus in the adult and in the midbrain in the young. Polidase was mainly soluble; over 55% was recovered in the S2fraction, and the rest was released from the particulate fractions by hypotonic shock. Brains of male rats contained a slightly higher level of the enzyme.