Acute ischemic changes in intestinal muscularis.

A chronologic study of ischemic changes in the mouse intestinal muscularis was done to delineate the morphologic alterations occurring within 24 hours of ischemia. The muscle cells initially contracted with segmental condensation of myofilaments. Subsequently, increasing degeneration and lysis of myofilaments resulted in the formation of dense degenerative bands and nodules alternating with clear segments in the muscle cells. Eventually, the myofilaments disintegrated. Mitochondria were initially swollen and subsequently condensed, shrunken, and fragmented. The plasma membrane showed progressive dissolution and eventually disappeared. These ultrastructural changes were represented by discernible changes in the histologic sections.