| ObjectiveTo observe the changes in the leve of serum tumor necrosis factor-α(TNF-α) and sciatic nerve growth factor (NGF) in diabetic SD rats and effects of Jinmaitong on the two factors, laying foundations of further exploration whether inflammatories cytokines-induced secretion of neurotrophic factors is related to the mechanism of Jinmaitong promoting repair of nerve injuries.MethodsSPF SD rats were given once intraperitoneal injection of streptozotocin (STZ) according to the dose of60mg/kg body weight, so dia betic rat s model were copied.30DM rat models were rand omly divi ded into the diabetic model (DM) group (n=10), the Jinmaitong (JMT) group (n=10) and the neurotropin (Ntp) group (n=10) with a random number table. Meanwhile, the normal control (Con) group (n=10) was setup. After those were successfu lly copied, rats were given by the in tragastric admini stration. The Jinmaitong group was given15times of the adult dosage (1.3125g/Kg-d). The neurotropin group was given15times of the adult dosage (8NU/Kg·d). These were given by q.d. The DM group and the Con group were given by equal volume of distilled water,and all groups were give n fo r16weeks. To make sure the surviv al of successfully modeling rats, rats in each diabetic group were given subcutaneous injection of1-4IU protamine zinc insulin injection q.d. The general conditions including mental status、daily activities、hair color, feeding, water intake, urine and rats’weight were observed. The rats’ weight was measured before intragastric administration, and aft er their intraga stric admini stration for4,8,12and16weeks, respectively, and the blood glu cose was mon itored. At the intragas trie admini stration for16weeks, the mechan ical pa in thre shold was measure ed with all rats and then they were sacrificed. Generally the sciati c nerve was taken under anesthesia. The blood specimen was taken from the CA (carotid artery) and the serum was saved. HE staining was used for observation of the pathological change of sciatic nerve. The immunohistochemistry assay was used for measuring the NGF level in the sciatic nerve. The enzyme-linked immunosorbent assay was used for measuring the serum TNF-a level.Results1. After the model was successfully established (before intragastric administration) the BG (blood glucose) level in all of the treatment groups was obviously elevated com pared with the Con group (P<0.05). Then there was no obvious difference during each of the treatment groups and the DM group at all the time point (P>0.05)2. Before intrag astric admini stration, there was no out stading difference in rat s’body w eight between each of the experimental groups and the Con group (P>0.05). With the intrag astric adm inistration for four weeks, the rats’body weight in the diabetic model group was significantly crashed co mpared wi th the nor mal gro up (P<0.05). Afte r intrag astric adminis tration for4we eks, there was no outstading difference during the Con grou p and t he Jinmaitong grou p or the neurotropin group (P>0.05),while there was also no outstading difference by the diabetic model group and t he Jinmai tong group o r the neuro tropin group (P>0.05). After int raga stric admini strat ion for8,12a nd16we eks, the body weight in the JMT and Ntp groups w as obviously slipped compared with the Con group (P<0.05), and the variouss exp erimental groups were likely (P>0.05)3. The average of bilateral mechanical pain thresholds in each experimental group was obviously crashed by the Con group (P<0.05); but that in the DM1group was significantly slipped compared with Con, JMT and Ntp group (P<0.05), while there was no outstanding difference with in the Jinmaitong group and the neurotropin group (P=0.959>0.05)4. The IOD (Integrated option density) value of the immunohistochemical staining of the rats’sciatic nerve in the DM group was visibly crashed in comparison with the JMT group and the Con group (P<0.05), while there was no noticed differ ence be tween the Jinm aitong group and the control group (P=0.967>0.05). And then there was no manifest difference compared the neurotropin group with the any other groups (P>0.05)5. The rat serum TNF-a levels in the DM group was significantly reduced in comparison with the Con group and the JMT group (P<0.05)> but there was no ma nifest differen ce com pared the N tp group with the J MT group or the Con group (P>0.05).Conclusions1. After a fasting single intra peritoneal injection S TZ(Streptozotoein) by60mg/kg for16weeks, the mech anical pain thre shold is dropped in the DM rats. So that the rat model of dia betic peri pheral neur opathy is successfully copied.2. The expression level of N GF in the sci atic ne rve of DPN rats is visibly de creas--ed.3. Jinmaitong can significantly improve the decreased mechanical pain threshold in DPN rats and upregulate NGF expression which is in the sciatic nerve.4. Jinmaitong can increase the serum level of TNF-a. |
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