TUBULAR NETWORKS IN SOLEUS MUSCLE-FIBERS OF THE RAT FOLLOWING TENOTOMY .1. SPATIAL-ORGANIZATION

Complex systems of tubules, 30 - 40 nm in diameter, were observed in m yofibers of the soleus muscle of Wistar rats following experimental tr ansection of the Achilles tendon. The appearance of these systems vari ed remarkably, depending upon the plane of sectioning. The spacial arr angement of the tubules was reconstructed by comparing several section s through individual systems. Such reconstructions revealed that they are networks of tubular elements arranged in an hexagonal pattern. A t hree-dimensional wire model was prepared, illustrating the spatial org anization of the tubular systems. The model consists of four groups of lattices with a honeycomb-like arrangement. The lattices of each grou p are parallel to one another, and intersect those of the other groups at an inclination of 60-degrees.