5-羟色胺转运体基因多态性与肠易激综合征的相关性

Expression of 5-HT and SP in the rectum of rats during heroin abstinence, detoxification or relapse

AIM: To investigate the expression of 5-hydroxytryptamine (5-HT) and substance P (SP) in the rectum of rats during heroin abstinence, detoxication, and relapse.

METHODS: Male Sprague-Dawley rats were divided into normal control group (NCG), saline control group (SCG), and experiment group (EG). The EG group was further divided into heroin abstinence group (HAG), methadone detoxication group (MDG), and heroin relapse group (HRG). Rectum tissue samples were taken from each group to perform immunohistochemistry to detect the expression of 5-HT and SP.

RESULTS: Compared with the NCG and SCG groups, the immunostaining density of 5-HT- and SP-positive cells was greater, the numbers of 5-HT- and SP-positive cells increased (5-HT: 10 d: 5.09 ± 3.39 vs 3.16 ± 2.05, 2.80 ± 2.13; 24 d: 5.05 ± 3.04 vs 3.16 ± 2.05, 2.81 ± 1.85; SP: 10 d: 2.55 ± 1.35 vs 1.29 ± 0.86, 1.37 ± 0.93; 24 d: 2.57 ± 1.27 vs 1.29 ± 0.86, 1.39 ± 0.79, all P < 0.05), and the mean grey degree of 5-HT- and SP-positive cells decreased (F = 36.642, 4.583, P < 0.05) in the HAG and HRG groups. Compared with the NCG and SCG groups, there were no statistical significances in the immunostaining density, numbers, and mean grey degree of 5-HT- and SP- positive cells in the MDG group (all P > 0.05).

CONCLUSION: Altered expression of 5-HT and SP in the tunica mucosa recti of rats during heroin abstinence or relapse suggests that 5-HT and SP can regulate the recovery of digestive function during heroin abstinence, detoxification, and relapse.

Correlations of substance P with interleukin-2 and interferon-γ expression in colonic mucosa of patients with post- and non-post-infectious irritable bowel syndrome

AIM: To investigate relationship between substance P (SP) activity and expression of interleukin-2 (IL-2) and interferon-g (IFN-γ) in colonic mucosa from patients with post-infectious irritable bowel syndrome (PI-IBS).

METHODS: Mucosal biopsy samples were obtained by colonoscopy from the descending colon and rectum of 77 patients (n = 21 and 52, for PI-IBS and non- PI-IBS, respectively) and 30 controls. The expression of SP, IL-2, and IFN-γ were determined by immunohistochemistry.

RESULTS: The expressions of SP was significantly higher in the descending colon and rectum mucosa from PI-IBS patients than that from non-PI-IBS patients (t = 2.321, 2.452, 2.414, 2.520, P < 0.05) and controls (t = 3.623, 3.722, 3.454, 3.561, P < 0.01). The positive rates of IL-2 and IFN-g were also markedly higher in PI-IBS patients than those in the controls (χ² = 13.781, 13.890, 14.012, 13.931, P < 0.01) and non-PI-IBS patients (χ² = 10.010, 9.892, 9.984, 10.152, P < 0.05). The expression of SP in PI-IBS patients with positive IL-2 and IFN-g was significantly increased as compared with the controls (t = 2.202, 2.220, 2.301, 2.252, P < 0.05) and non-PI-IBS patients (t = 2.182, 2.230, 2.194, 2.174, P < 0.05). There were no significant differences between the controls and non-PI-IBS patients.

CONCLUSION: Gastrointestinal infection may take part in the pathogenesis of IBS through neuroimmune mechanism.