Effects of mu and kappa opioid receptor agonists and antagonists on contraction of isolated colon strips of rats with cathartic colon.

AIM: To study the effects of mu and kappa opioid receptor agonists and antagonists on the isolated colon strips of rats with cathartic colon. METHODS: Cathartic colon model was established by feeding rats with contact laxatives, and effects of mu and kappa opioid receptor agonists and antagonists on electricity-stimulated contraction of isolated colon strips of rats with cathartic colon were observed. RESULTS: Compared with control group, exogenous mu and kappa agonists inhibited significantly electricity-stimulated contraction of strips of cathartic colon (8.50+/-0.89 mm, 6.24+/-0.91 mm, 3.35+/-0.6 mm vs 11.40+/-0.21 mm P<0.01; 8.98+/-0.69 mm, 6.89+/-0.71 mm, 4.43+/-0.99 mm vs 11.40+/-0.21 mm, P<0.01). In contrast, the exogenous mu antagonist significantly enhanced electricity-stimulated contraction of isolated colon strips (13.18+/-0.93 mm, 15.87+/-0.98 mm, 19.46+/-1.79 mm vs 11.40+/-0.21 mm, P<0.01), but kappa antagonist had no effect on the isolated colon strips of rats with cathartic colon. CONCLUSION: Mu and kappa opioid receptors are involved in the regulation of colon motility of rats with cathartic colon.

[Study on distribution of interstitial cells of Cajal in the sigmoid colon of patients with slow transit constipation].

OBJECTIVE: Slow transit constipation (STC) is a colonic motor disorder whose etiology remains unclear. Recent studies have demonstrated a crucial role for interstitial cells of Cajal (ICC) in regulation of intestinal motility. The aim of this study was to examine the distribution of ICC within the normal sigmoid colon and STC patients. METHODS: Twelve patients with STC and eight age-matched controls were studied. 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 image analysis software. RESULTS: ICC were located in the external muscle layers including longitudinal muscle (LM), myenteric plexus (MP), circular muscle (CM) and submucosal border (SMB). Two types of Kit-positive ICC were observed: bipolar cells characterized by one or two long processes, and multipolar cells with long stellate processes extending in various directions. A higher percentage of ICC was present in the MP regions and CM layers compared with the SMB and LM layers. Tissues from STC patients showed considerably decreased in number of ICC located in the four regions (ICC-LM, ICC-MP, ICC-CM, ICC-SMP), especially for ICC-SMP, almost completely disappeared. CONCLUSION: Decreased c-kit + ICC in number may play an important role in the pathophysiology of STC. It remains to be determined whether loss of ICC is primary or secondary to another lesion.

[Role and significance of pelvic four-contrast defecography in the diagnosis of outlet obstructive constipation].

OBJECTIVE: To study the changes in pelvic floor morphology and relationships of the pelvic organs in patients with outlet obstructive constipation (OOC). METHODS: Fifty-nine OOC patients and 12 healthy volunteers were examined by simultaneous pelvic four-contrast defecography, including pelvicography, vaginal opacification, voiding cystography and defecography. The levels of perineum, peritoneum and bladder, and anorectal angle were measured and recorded. RESULTS: Among the 59 OOC patients, 46 cases of internal rectal prolapse (IRP), 29 cases of pelvic floor hernia, 7 cases of rectocele (RC), 7 cases of spastic pelvic floor syndrome (SPFS), 5 cases of descending perineum syndrome were diagnosed by pelvic four-contrast defecography. Six cystoceles and 10 uterine prolapses were also found by pelvic four-contrast defecography. Compared with healthy volunteers, OOC patients had significantly large anorectal angles during defecation (P<0.05), abnormality descending of perineum during rest and defecation (P<0.05, P<0.01), and a deep pouch of Douglas during defecation (P<0.01). OOC patients combined with urinary system symptoms had an abnormal descent of the bladder during rest and defecation (P<0.05, P<0.01). CONCLUSION: Pelvic four-contrast defecography is an effective method for the diagnosis of IRP, RC, pelvic floor hernia, peritoneocele, cystocele and uterine prolapse, and is helpful in the selection of proper surgical procedures for the treatment of OOC.

Role of pelvicography and colpocystodefecography in diagnosis of outlet obstructive constipation.

AIMS: The aim was to research the changes in pelvic floor morphology and corresponding visceras in patients with outlet obstructive constipation (OOC). PATIENTS AND METHODS: Thirty-eight patients with OOC and 12 healthy volunteers were enrolled in this study. With simultaneous pelvicography and colpocystodefecography (PCCD), including pelvicography, vaginal opacification, voiding cystography and defecography, pelvic floor morphology was observed and the anorectal angle, the level of the perineum, peritoneum and bladder were measured. RESULTS: Thirty-seven cases of internal rectal prolapse (IRP), 5 cases of rectocele (RC) and 5 cases of spastic pelvic floor syndrome SPFS were diagnosed by PCCD. 12 IRP, 4 RC and 1 SPFS were detected by common physical examination. All of these were confirmed by PCCD. Moreover, PCCD found 9 pelvic floor hernia or peritoneoceles, 6 cystoceles, 3 descending perineum syndromes and 10 uterine prolapses. Compared with controls, OOC patients had a significantly large anorectal angle during defecation, abnormal descending of the perineum at rest and during defecation, and a deep pouch of Douglas during defecation. Some patients with urinary system symptoms may have had an abnormal descent of the bladder during rest and defecation. CONCLUSION: Simultaneous PCCD has a higher positive ratio than the common physical examination in diagnosing IRP and RC, and provides information for the diagnosis of pelvic floor hernia or peritoneocele, cystocele or uterine prolapse. PCCD is helpful in the selection of a proper surgical procedure.

Expression of c-kit messenger ribonucleic acid and c-kit protein in sigmoid colon of patients with slow transit constipation.

BACKGROUND AND AIMS: The c-kit protooncogene receptor and its ligand stem cell factor regulate the proliferation and survival of germ cells as well as interstitial cells of Cajal (ICCs). Decreased numbers of ICCs and defects in its networks have been reported in the colon of patients with slow transit constipation (STC). However, little information about the c-kit messenger ribonucleic acid (mRNA) and protein expression in the constipated colon is available. The aim of this study was to determine whether the expression of c-kit mRNA and c-kit protein declined in the colon in STC. PATIENTS AND METHODS: The sigmoid colonic samples from 12 patients with STC and from eight age-matched patients with non-obstructed colorectal cancer were used for this study. Expression of c-kit mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR), and expression of c-kit protein was detected by Western blot analysis. RESULTS: Decreased expression of c-kit mRNA was demonstrated in the STC group compared with the control group. The ratio of c-kit and beta-actin was 1.26+/-0.32 in controls and 1.17+/-0.41 in the STC group (U=0.500, P=0.029). c-kit protein expression significantly declined in the STC group. The mean value of optical density was 162.97+/-5.43 in the control group and 96.64+/-8.80 in the STC group (U=0.000, P=0.021). CONCLUSIONS: The data indicate that the expression of c-kit mRNA and c-kit protein significantly decreased in the colon of STC, suggesting that the c-kit signal pathway may play an important role in ICC reduction in STC.

Decreased interstitial cells of Cajal in the sigmoid colon of patients with slow transit constipation.

BACKGROUND AND AIMS: 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. PATIENTS AND 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.