Degeneration of varicose axons and their phagocytosis by smooth muscle cells.

Intramuscular varicose axons of the guinea-pig vas deferens were studied by electron microscopy after surgical and chemical denervation. The intervaricose segments disappear, and the varicosities become disconnected, spherical in shape and either swollen or more electron-dense. Other varicosities, presumably more advanced degenerative stages, appear as phagosomes in the cytoplasm of Schwann cells and of smooth muscle cells. Smooth muscle cells are extensively involved in the process of elimination of the degenerated nerve varicosities.