[Vagal chronic stimulation decreased colonic Cajal cells density in rats]

Interstitial CaJal cells ICC) function as pacemaker cells for the smooth muscle of the gastrointestinal (GI) tract. They are binding muscles with the enteric nervous system creating network and play an important role in the regulation of motility of the GI tract. Previous data from our laboratory show that chronic vagal stimulation leads to decrease of body weight of examined animals. We propose, that this effect could be mediated not only by central mechanisms, but also is observed as a result of disturbances of peristalsis caused by damage o interstitial cells of Cajal (ICC). In this study we evaluate density of the ICC in the proximal colon in rats with chronic vagal stimulation (MC) microchip (1-month stimulation, frequency of 0.1 Hz).

One month after implantation of microchip proximal colon was taken from MC and control rats (n=14). An immunohistochemical method--staining with specific antibodies against c-kit receptor (CD117--Santa Cruz Biotechnology)--was performed. The result of this reaction in the region of colonic myenteric plexuses was morphometrically assessed using computed image analysis.

Amount of ICC in colonic myenteric plexuses decreased in MC group (3.2 +/- 1.10% of muscular layer) in comparison to the control group (4.86 +/- 1.02% of muscular layer) (p < < 0.05). No differences of the other morphometrical parameters of the muscle layers in both groups were observed.

Colon ICC count decrease in response of chronic vagal stimulation which confirms possibility of disturbances of colonic motility, but mechanism remains unclear.