THE RELATIONSHIP BETWEEN MYENTERIC NEURONAL DENERVATION, SMOOTH-MUSCLE THICKENING AND EPITHELIAL-CELL PROLIFERATION IN THE RAT COLON

The effects of myenteric neuronal denervation on smooth muscle thicken ing and epithelial cell proliferation were studied in the descending c olon of rats treated by serosal application of 2 mM benzalkonium chlor ide (BAG) for 30 min. Control animals were treated with saline (0.9% N aCl). The animals were divided into six groups of 13 animals each and killed 10, 45 and 120 days after BAC treatment. A significant reductio n in neuron number was observed in the myenteric plexus of animals tre ated with BAG, as well as smooth muscle thickening and an increase in crypt cell population, crypt cell production per crypt and a decrease in cell cycle time. These findings permit us to conclude that a relati onship may exist between the increase of epithelial cell proliferation , smooth muscle thickening and myenteric neuron denervation in the des cending colon caused by BAG, the latter probably playing an important role in the integration of the other two.