Intra- and extracellular lysosomes in tendon tissue of the mouse after treatment with an anabolic steroid hormone: Ultrastructural and cytochemical study

Ultrastructural observations of fibroblasts from 6-week-old mouse tendons were carried out at different times after treatment with an anabolic steroid. The characteristic response of the fibroblasts involves the appearance of great numbers of intracellular lysosomes and the emergence of matrix vesicles, some of which could be identified ultrastructurally by their positive reaction for acid phosphatase as extracellular lysosomes. It is suggested that this fine structural gradient after treatment with the anabolic steroid results from, and may be directly the cause of. an increased level of cyclic AMP. The experimental design and the discussion of the findings consider, on the one hand, the use of anabolic steroid hormones in clinical practice and. on the other hand, the appearance of a collagen dysplasia in competitive sports.