ABSTRACT
Objective To investigate the expression of transit receptor potential ankyrin 1 (TRPA1) and 5-hydroxytryptamine (5-HT) in the colonic mucosa of patients with slow transit constipation (STC).Methods The clinical data of 10 patients with STC and 10 patients with sigmoid cancer who were respectively admitted to the Daping Hospital of the Third Military Medical University from March 2013 to March 2014 and from December 2013 to May 2014 were retrospectively analyzed.Ten and 10 surgical specimens of descending colon from patients with STC and sigmoid cancer (tumor edge measuring in controls ＞ 10 cm) were allocated into the STC group and the control group,respectively.The expressions of TRPA1 and 5-HT in the colonic mucosa in the control group and in the 2 groups were detected by immunofluorescence and immunochemistry staining,respectively.The expression of TRPA1 in the colonic mucosa was observed by Western blot test.The measurement data with normal distribution was presented as x ± s,and the comparison between groups were analyzed using the t test.Results The results of immunofluorescence showed that TRPA1 and 5-HT were co-expressed in the colonic mucosa of controls.The results of immunochemistry staining showed that the integrated optical density (IOD) of expressions of TRPA1 and 5-HT in the STC group and in the control group were 3 619 ± 1 702,55 721 ±28 613 and 9 894 ± 3 325,12 949 ± 2 200,respectively,showing significant differences between the 2 groups (t =-5.312,4.713,P ＜ 0.05).The results of Western blot test showed that the relative expressions of TRPA1 in the STC group and in the control group were 0.8 ± 0.3 and 1.5 ± 0.5,showing a significant difference between the 2 groups (t =-2.379,P ＜ 0.05).Conclusions TRPA1 is expressed in the enterochromaffin (EC) cells of colonic mucosa.High expression of 5-HT and low expression of TRPA1 in the colonic mucosa are closely related with the pathogenesis of STC.
ABSTRACT
Objective To investigate the effects of pelvic nerve transection on the colonic motility and the expression of transit receptor potential ankyrin 1 (TRPA1) in the colon mucosa.Methods Ninety-six Sprague-Dawley rats were divided into 3 groups based on a random number table:(1) 18 rats in the control group remained untreated and were fed regularly;(2) 39 rats in the sham operation group received laparotomy,and the pelvic nerves were stripped;(3) 39 rats in the operation group received laparotomy with pelvic nerve transection before abdominal closure.Colonic transit was assessed respectively at postoperative day 1,3,and 7 by injecting and calculating the geometric center (GC) of the distribution of 51Cr after 3 hours of propagation.The expression of TRPA1 in the colonic mucosa was determined by Western blot at postoperative day 1,3,7.Data with normal distribution were expressed by (x)± s,and were analyzed using the repeated measures ANOVA or LSD test.Results The GC values of the distribution of 51Cr in the sham operation group at postoperative day 1,3,7 were 5.8 ± 0.9,7.5 ± 0.5,7.3 ± 0.5,with a significant difference (F =9.508,P ＜ 0.05).The GC values of the distribution of 51Cr in the operation group at postoperative day 1,3,7 were 4.9 ± 0.4,5.6 ± 0.4,6.4 ± 0.8,with a significant difference (F =11.689,P ＜ 0.05).There were significant differences in the GC values of the distribution of 51 Cr at postoperative day 1 and 3 between the sham operation group and the operation group (t =2.227,7.144,P ＜ 0.05),while no significant difference was detected at postoperative day 7 (t =2.162,P ＞ 0.05).The results of Western blot showed that the relative expressions of TRPA1 in the proximal part of the colon at postoperative day 1,3,7 were 1.00 ± 0.05,1.00 ± 0.07,1.00 ± 0.06 in the control group,with a significant difference (F =0.055,P ＞ 0.05).The relative expressions of TRPA1 in the proximal part of the colon at postoperative day 1,3,7 were 0.78 ± 0.09,0.94 ± 0.08,0.95 ± 0.12 in the sham operation group,with a significant difference (F =5.651,P ＜ 0.05).The relative expressions of TRPA1 in the proximal part of the colon at postoperative day 1,3,7 were 0.37 ± 0.12,0.89 ± 0.10,0.92 ± 0.14 in the operation group,with a significant difference (F =41.005,P ＜0.05).There was significant difference in the relative expressions of TRPA1 in the proximal part of the colon among the 3 groups at postoperative day 1 (F =73.497,P ＜ 0.05),while significant differences were respectively detected between the control group and the sham operation group and the operation group at postoperative day 1 (t =4.224,11.954,P ＜ 0.05),and significant difference between the operation group and the sham operation group was also observed (t =7.730,P ＜ 0.05).There was no significant difference in the relative expression of TRPA1 in the proximal part of the colon among the 3 groups between day 3 and day 7 (F =2.087,0.656,P ＞ 0.05).The relative expressions of TRPA1 in the distal part of the colon at postoperative day 1,3,7 were 1.00 ± 0.05,1.00 ± 0.07,1.00 ± 0.06 in the control group,with no significant difference (F =0.055,P ＞ 0.05).The relative expressions of TRPA1 in the distal part of the colon at postoperative day 1,3,7were 0.68 ±0.11,0.98 ±0.12,1.11 ±0.16 in the sham operation group,with a significant difference (F =16.975,P ＜ 0.05).The relative expressions of TRPA1 in the distal part of the colon at postoperative day 1,3,7 were 0.39 ± 0.12,0.78 ± 0.10,1.06 ± 0.13 in the operation group,with a significant difference (F =50.417,P ＜ 0.05).There were significant differences in the relative expression of TRPA1 in the distal part of the colon among the 3 groups between day 1 and day 3 (F =58.773,8.680,P ＜ 0.05),while significant differences were respectively detected between the control group and the sham operation group and the operation group at postoperative day 1 (t =5.706,10.837,P ＜ 0.05),and significant difference was also detected between the operation group and the sham operation group (t =5.131,P ＜ 0.05).There was no significant difference in the relative expression of TRPA1 in the distal part of the colon between the control group and the sham operation group at postoperative day 3 (t =0.166,P ＞ 0.05),while significant differences were respectively detected between the control group and the operation group and between the sham operation group and the operation group at postoperative day 3 (t =3.694,3.528,P ＜ 0.05).There was no significant difference in the relative expression of the TRPA1 in the distal part of the colon between the 3 groups at postoperative day 7 (F =1.319,P ＞ 0.05).Conclusions Injury to pelvic nerves adversely affects colonic transit and expression of TRPA1 in mucosa.With a compensatory mechanism from the intestinal itself,these alterations in intestinal motility function normalize over time suggesting expression of TRPA1 in mucosa plays a crucial role in the recovery of intestinal motility function.