[Lysosomal proteinase activity and the the lysosomes of the small intestine in postnatal ontogeny].

It has been shown that in postnatal animals, the activity of lysosomal proteinases in the distal part of the small intestine was considerably higher than in the proximal one. With transition from milk to definitive nutrition, the activity of lysosomal proteinases gets equalized in the proximal and distal parts of the small intestine. The data concerning the proximo-distal gradient of distribution of the activity of lysosomal proteinases have been supported. Transition from milk to definitive nutrition has given rise to ultrastructural alterations in the lysosomal apparatus.