Protective effect of shenfu injection on intestinal mucosal ischemia-reperfusion injury and intestinal epithelial cells at recovery phase in rats

Daihong WANG; Xiaofei HE; Xiangchu LI; Chaoxin ZHENG; Xunchen ZHANG

ABSTRACT

BACKGROUND:

Apoptosis plays a key role in intestinal mucosal ischemia-reperfusion injury and recovery; meanwhile, effect of shenfu injection on apoptosis of intestinal epithelial cells during intestinal mucosal ischemia-reperfusion injury should be studied further.

OBJECTIVE:

To investigate the relationship between the apoptosis of intestinal epithelium and characteristics of intestinal mucosal ischemia-reperfusion injury and recovery.

DESIGN:

Randomized controlled animal experiment.

SETTING:

Department of General Surgery, Xianning Central Hospital;Department of General Surgery, Renmin Hospital of Wuhan University.MATERIALS The experiment was carried out in the Central Laboratory,Xianning Central Hospital from March to August 2005. Fifty-four healthy male SD rats weighting 200-250 g were provided by Animal Center of Medical School, Wuhan University.

METHODS:

The rats were divided randomly into 3 experimental groupscontrol group (n=6), ischemia-reperfusion group (n=24) and shenfu treatment group (n=24). ① Pentobarbital sodium solution (40 mg/kg) was administrated into the intraperitoneal cavity to induce anaesthesia. Through a midline abdominal incision, the mesenteric blood vessel of a 15-cm segment of mid-intestine was occluded for 60-minute with an atraumatic vascular forceps. The control group underwent the same procedure except for unblocking the mesenteric blood vessel. At the end of 60 minutes ischemia period the forceps was removed to allow reperfusion, the abdominal cavity was closed. ShenFu injection (8 mL/kg ·h, 20 mL/kg ·d, produced from Yaan Three-Nine Pharmaceuticals Co, No 030302) was injected 30 minutes before occlusion in SF treatment group, same quantity of 0.9% natrii chloride was injected in control group and ischemia-regeneration group at the same time, and oxygen was inbreathed during the operation and ischemia-regeneration. ② Experimental intestinal canals were sampled for the following analysis when all groups were respectively performed sham ischemia for 1 hour, intestinal ischemia for 1 hour and reperfusion for 1, 24and 72 hours. Sections were observed in light microscope. Histological mucosal damage in each sample was evaluated as followed scoring system 0score, normal muscosal villi and gland; 1 score, slight lesion near the tip of the villi; 2 scores, slight lesion of subepithelial gland; 3 scores, development of subepithelial (Gruenhagen) spaces near the tip of the villi with capillary congestion; 4 scores, extension of the subepithelial space with moderate epithelial lifting from the lamina propria; 5 scores, a few denuded villous tips; 6 scores, massive denuded villi; 7 scores, denuded villi with exposed lamina propria and obvious gland lesion; 8 scores, disintegrateon of the lamina propria; 9 scores, haemorrhage and ulceration. ③ The Tunel method (TdT mediated biotin-dUTP nick and labeling; TdT-Frag EL DNA fragmentation detection kit) was used. Inbrief, this method allowed the identification of apoptosis nuclei in tissue samples through DNA fragment and labeling. Apoptosis Index (AI) was set as the average number of apoptosis cells in per 100 cells by observing ten high power fields of adjacent villi and crypts. ④ The mitotic phase of crypt epithelial nucleus within intestinal mucosa was observed in intestinal sections stained with haematoxylin and eosin. The number of cells with nucleus mitotic phase was counted in ten adjacent mucosal crypts, which was taken as the index of mitotic activity of intestinal mucosal epithelial cell.MAIN OUTCOME

MEASURES:

Intestinal mucosal histopathological changes, apoptosis of intestinal mucosal epithelial cell and mitotic activity of intestinal mucosal crypt.

RESULTS:

All 54 rats were involved in the final analysis. ①) Scores of histopathological changes were (0.65 ±0.35) points in 1-hour ischemia group, (3.87±0.86) points in 1-hour reperfusion group and (0.65±0.35)points in 24-hour reperfusion group; which were lower than those in ischemia-reperfusion group [(7.11±1.01), (8.05±1.34), (1.53±0.48) points; P＜ 0.05]. ② Indexes of apoptosis were 17.24±7.05 in 1-hour ischemia group, 24.20±9.87 in 1-hour reperfusion group, 11.49±4.71 in 24-hour reperfusion group and 6.02±2.16 in 72-hour reperfusion; which were lower than those in ischemia-reperfusion group (51.09±13.76, 54.89±15.58,23.54±9.64, 12.47±5.52; P ＜ 0.05). Activities of mitosis were 10.37±2.03and 11.72±2.07 in 1-hour ischemia group and 1-hour reperfusion group,respectively; which was higher than those in ischemia-reperfusion group(8.24±1.69, 9.95±1.93; P ＜ 0.05).

CONCLUSION:

Shenfu injection can significantly attenuate apoptosis of intestinal epithelium, increase crypt mitotic activity, and promote intestinal epithelium regeneration or repair.