| Objective:To investigate the effect of single dose of localinjection with Ropivacaine Hydrochloride on the healing of abdominal incision in rats and its mechanism.Methods:Sixty 21 dayoldmale SD rats (70-100g) were selectedand randomly divided into two groups:Ropivacaine group (group A, n=30) and Saline group (group B, n=30). All rats were anesthetized by inhalation of Sevoflurane followed by establishment the model of abdominal incision. The A group rats were given 0.3% Ropivacaine Hydrochloride (0.6ml) and the B group rats were given 0.9% sodium chloride (0.6ml) subcutaneously after suturing.After the procedure, instead of inhalation of oxygen for the recovery from anesthesia, the recovery period and the degree of postoperative pain was recorded. Six rats were selected from each group for natural healing of the incision and was noted the required time for the complete healing. Six rats in each group were sacrificed in first day, third day, seventh day, and in 14th day after operating.The incision and surrounding skin tissue were examined by pathological methods. The pathological changes were observed under the microscope using by HE staining, and the neutrophil and lymphocyte were counted. The expression of collagen type 1 (protein CP I, collagen I) in fibroblasts was observed by immunohistochemical method.Results:(1) Compared with the control group,the degree of postoperative pain was lesser, and the body curly were accounted for only 20% in experimental group,all rats of control group showed the body curly. Postoperatively after the recovery from anesthesia,86.6% showed immediate activity in experimental group, but only 26.6% were accounted in control group(P<0.05). The time of regaining consciousness postoperative was no significant difference (P>0.05) between the two groups.(2) The average healing times(16.83±5 2.48 days) was shorter in experimental group than that the control group (22.00 ± 0.89 days) (P<0.05).(3)In 1st,3rd,7th and 14th postoperative days,the degree of inflammation in superficial dermis was significantly lower and early proliferation of granulation tissue was significantly faster in the experimental group than that the control group.In 14th postoperative day,thefibrotic tissue was significant proliferationand the degree of healing was wellin the experimental group.(4)The inflammatory cell count showed that the number of neutropils in experimental groups was lesser than that the control groups (P<0.05) in different postoperative days, especially in 3r,71 and 14th day (P<0.01).The number of lymphocytes was also significantly less in experimental group than that the control groups (P<0.05) in 1st and 14th postoperative day,(5) IHC staining showed that the expression of fibroblasts in the superficial dermis tissue was higher in experimental group than that the control group, especially in 7th and 14th postoperative days,and also showed that thestrong positive expression (+++) in the experimental group.Conclusion:Ropivacainecan reduce inflammation and promote granulation tissue proliferation,and accelerated healing of the incision. Ropivacaine may play a significant role in analgesic effects ofpediatric postoperative and incision healing. |
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