Presence of intra-mucosal smooth muscle cells in normal human and rat colon.

Intramucosal smooth muscle cells surrounding the crypts and originating from the muscularis mucosae were observed in normal human and rat colon. Immunohistochemical techniques, using anti-desmin and anti-actin antibodies, along with ultrastructural procedures were employed to investigate the nature and distribution of these cells. Desmin-positive and actin-rich smooth muscle cells sprouting from the muscularis mucosae into the lamina propria and surrounding the crypts were observed both in rat and human colon. The intramucosal smooth muscle cells may play an important role in some pathophysiological conditions.