Abstract: thor: Tong Weidong, Email: vdtong@163.com
【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:Ninetysix SpragueDawley 〖HQK〗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 ±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 51Cr 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, 7 were 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.