Sleep restriction induces histoarchitectural and cellular remodeling in the rat distal colon: a peripheral consequence of circadian disruption.

Sleep restriction disrupts circadian organization and represents a behavioral condition with systemic consequences that extend beyond the central nervous system. In this study, we evaluated structural and cellular changes in the distal colon of rats exposed to sustained sleep restriction. Sixteen male Rattus norvegicus were assigned to a control group (n = 8) or a sleep-restricted group (n = 8) and subjected to a modified multiple-platform protocol for 21 days. Blood samples were collected for inflammatory assessment, and the distal colon was analyzed using histochemical and immunohistochemical approaches. Sleep-restricted rats exhibited reduced body mass gain and an increased proportion of polymorphonuclear leukocytes. In the distal colon, sleep restriction increased mucosal thickness and crypt depth, depleted goblet cells, and caused mast cell hyperplasia. It also produced quantitative and morphometric changes in neurons and enteric glial cells in the myenteric and submucosal plexuses. Notably, these alterations occurred in the absence of macroscopic mucosal lesions. Together, these findings demonstrate that sustained sleep restriction promotes coordinated remodeling of distal colonic histoarchitecture, epithelial composition, immune-related cells and enteric neuro-glial organization. Considering that sleep restriction disrupts circadian entrainment and alters behavioral patterns such as feeding, these results support the concept that intestinal remodeling represents a peripheral consequence of circadian disruption.