Decreased interstitial cells of Cajal in the sigmoid colon of patients with slow transit constipation.
OBJECTIVE
Slow transit constipation (STC) is a colonic motor disorder that is characterized by measurably delayed movement of materials through the colon. Although abnormalities in the neuronal networks of the colon have been demonstrated in patients with STC, the etiology of STC remains unclear. Interstitial cells of Cajal (ICC) have been shown to be the pacemaker cells of the intestine and have been implied in the pathogenesis of a number of gastrointestinal motility dysfunctions, including idiopathic STC. This study aimed to determine the normal distribution of ICC within the colon of the Chinese and also to determine if ICC are decreased in Chinese STC patients.


METHODS
Twelve patients with STC and eight age-matched normal controls were studied. Specimens of sigmoid colon were obtained immediately after resection. ICC were identified with a monoclonal antibody to c-kit by an indirect immunofluorescence method. Immunostained tissues were examined with a laser scanning confocal microscope and the area occupied by ICC was calculated with an image analysis system.


RESULTS
ICC were located in the external muscle layers including myenteric plexus (MP) and submucosal border (SMB). Two types of Kit-positive ICC were observed: bipolar cells characterized by one or two long processes and multipolar cells characterized by long stellate processes extending in various directions. A higher percentage of ICC was present in the MP regions and circular muscle (CM) layers compared with the SMB and longitudinal muscle (LM) layers. Tissues from STC patients showed a considerable decrease in the number of ICC located in the four regions (ICC-LM, ICC-MP, ICC-CM, ICC-SMB), especially the ICC-SMB, in which ICC almost completely disappeared.


CONCLUSIONS
Similar distribution of ICC was observed in the normal sigmoid colon of the Chinese. Decreased area of c-kit+ ICC may play an important role in the pathophysiology of STC. It remains to be determined whether the loss of ICC is primary or secondary to another lesion.
Tong
Wei-Dong
WD
Department of General Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China. vd_tong@yahoo.com.cn
Liu
Bao-Hua
BH
Zhang
Lian-Yang
LY
Zhang
Sheng-Ben
SB
Lei
Ying
Y
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D016022:Case-Control Studies; D012809:Colon, Sigmoid / Q000166:cytology* / Q000473:pathology; D003248:Constipation / Q000503:physiopathology*; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis
D000911:Antibodies, Monoclonal; D019009:Proto-Oncogene Proteins c-kit