[Distribution and activities of enzymes in humeral epiphyses of albino rats of a specific age].

In the cartilage epiphysis of newborn, 8-, 30-, and 60-day-old Sporague-Dawley rats, 5'-nucleotidase, adenosine triphosphatase, alkaline and acid phosphatase activities were found. The main centre of activity of nearly all enzyme reactions is situated, with only small temporal differences in animals of all age groups in the middle and distal cells of the column cartilage, the proximal hypertrophic cells and the chondrocytes of the opening zone. The cells of the tangential layer in the articular cartilage of newborn and 8-day-old rats demonstrate 5'-nucleotidase activity.