Growth characteristics of normal and dystrophic myoblasts in primary myoblast cultures.

This study employed immunocytochemistry and toluidine blue counterstaining to compare different procedures utilized in primary myoblast cultures, from which an optimal culture model for normal myoblasts could be derived. The growth characteristics of normal and dystrophic myoblasts were also investigated by means of this model. Results indicate that the requirements for an ideal myoblast culture should include a combined enzyme of 0.25% trypsin and 0.2% collagenase (type IV) (1:1), a preplating time of approximately 15-20 minutes, and a seeding density of 1 x 10(5) cells/ml. Furthermore, the mouse samples should be newborn mice. A better proliferative capacity of myoblasts was noted in an incubator with 10% CO2 coupled with Dulbecco's MEM plus 15% fetal calf serum. With regard to the growth characteristics of normal and dystrophic myoblasts, the doubling time of normal myoblasts was shorter than that of dystrophic myoblasts. In terms of the fusion percentage of myoblasts, dystrophic myoblasts tended to fuse earlier than normal ones, especially after 5 days in culture. The findings of this study are valuable in understanding the myogenesis of myoblasts under different culture conditions. The establishment of requirements for good growth of myoblast cultures will facilitate myoblast transfer therapy. Finally, the growth characteristics of normal and dystrophic myoblasts as well as variances in the proliferation and differentiation of these two types of cells are clarified.