Effects of pelvic nerve transection on the colonic motility and the expression of transit receptor potential ankyrin 1 in a rat model / 中华消化外科杂志

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.