Gap junctions between fibroblasts in rat myotendon.

We applied conventional and freeze-fracture electron microscopy to study intercellular contacts between the processes of fibroblasts in the myotendon of the rat exterior digitorium longus. The results showed well defined gap junctions between the cell processes, while other cell junctional structures such as tight junctions and desmosomes were not recognizable. The present study suggests that the gap junctions represent a structure to coordinate the activities of fibroblasts distributed in the myotendon of the muscle.