Most studies provide strong support for an etiologic role of stressful life events in irritable bowel syndrome (IBS). Consistent with the observations in both patients and doctors that psychosocial disturbances seem to precede the onset or exacerbation of gut symptoms, researches have consistently found high levels of emotional distress in a proportion of patients with IBS and other functional gastrointestinal disorders. Moreover, a variety of other potentially psychiatric diseases such as anxiety, depression, and sleep disorder also coexist frequently with IBS. In recent literatures, some studies have shown altered mechanoelastic properties such as colonic tone, compliance, and accommodation. The demonstrated differences in colonic compliance and accommodation suggest peripheral neuromuscular substrate contributing to the pathogenesis of IBS. However, until now, attention has focused on the disturbances of visceral hypersensitivity rather than on gastrointestinal motor function as a hallmark of IBS pathophysiology. But not all IBS patients show decreased rectosigmoid pain thresholds. Recent advances in brain imaging have allowed investigators to measure changes in regional cerebral blood flow during stimulation. Those methods have extended our understanding of brain function and brain-gut interaction. IBS is characterized by hypersensitivity to visceral sensation and augmented response to stress. Studies on the disorders of sensori-motor function have also contributed to understand the knowledge of neurotransmitters involved in the function of the enteric nervous system and to identify targets for the development of new treatments for IBS.
Brain/physiology ; Humans ; Intestines/innervation/physiopathology ; Irritable Bowel Syndrome/physiopathology/*psychology ; Stress, Psychological/complications/physiopathology

OBJECTIVETo observe the effects of Dachengqi Decoction (大承气汤, DCQD) on morphological changes in the network of enteric nerve-interstitial cells of Cajal (ICCs)-smooth muscle cells (SMC) of enteric deep muscular plexuses (DMP) in the rats with multiple organ dysfunction syndrome (MODS).

METHODSOne hundred Wistar rats of both sexes weighing 200 to 250 g were randomly divided into the control group, MODS group, and DCQD group. The morphologic changes of enteric nerve-ICC-SMC network in the DMP of intestine was observed using c-Kit and vesicular acetylcholine transporter/neuronal nitric oxide synthase immunohistochemical double-staining with whole-mount preparation technique, confocal laser scanning microscopy, and electron microscopy.

RESULTSCompared with the control group, the distribution and densities of cholinergic/nitrergic nerves and ICC in the DMP (ICC-DMP) of intestine in the MODS group were significantly decreased (P<0.01), and the network of cholinergic nerve-ICC-SMC was disrupted; and the ultrastructural features of ICC-DMP, enteric nerve, and SMC were severely damaged. After treatment with DCQD, the damage in the network of enteric nerve-ICC-SMC was significantly recovered. Compared with the MODS group, the distribution and densities of cholinergic/nitrergic nerves and ICC-DMP in the DCQD group were significantly increased (P<0.01); and the ultrastructural features of ICC-DMP, enteric nerve, smooth muscle cells were significantly recovered.

CONCLUSIONSDCQD can improve the gastrointestinal motility in MODS. The mechanism may be related to the effect of repairing the damages in the network of enteric nerve-ICC-SMC.

Animals ; Interstitial Cells of Cajal ; cytology ; Intestines ; innervation ; Microscopy, Confocal ; Multiple Organ Failure ; physiopathology ; Plant Extracts ; therapeutic use ; Rats