ABSTRACT
OBJECTIVE: To investigate the effect of electroacupuncture (EA) at "Jiaji" (EX-B2) at different time points on the expression of OX-42 (a monoclonal antibody with specific expression of complement receptor-3 in spinal microglial cells) and purinergic receptor P2X4 (P2X4) in rats with chronic constriction injury (CCI) of the sciatic nerve, as well as the possible after-effect mechanism of EA analgesia in neuropathic pain. METHODS: Sprague-Dawley rats were randomly divided into blank group, model group, immediately after EA group, 0.5-hour after EA group, 1-hour after EA group, 2-hour after EA group, 4-hour after EA group, 12-hour after EA group, and 24-hour after EA group, with 6 rats in each group. The rats in the model group and the EA groups were used to establish a model of CCI-induced neuropathic pain, and those in the immediately after EA group and the 0.5, 1, 2, 4, 12 and 24 hours after EA groups were treated with EA at bilateral L3 and L5 "Jiaji" points for 20 min after 7 d of modeling. Samples were collected immediately and at 0.5, 1, 2, 4, 12, and 24 hours after EA, and for the rats in the blank group and the model group, samples were collected after fixation the rats for 20 min. Heat pain threshold was observed before and after intervention, and immunohistochemistry was used to measure the protein expression of OX-42 and P2X4 in the spinal cord lumbar enlargement. RESULTS: After 7 days of modeling (before intervention), compared with the blank group, the heat pain threshold had a significant reduction in the model group and the EA groups (P<0.01). Compared with the model group after intervention, the immediately after EA group and the 0.5, 1 and 2 hours after EA groups had a significant increase in heat pain threshold (P<0.05). Compared with the model group, immediately after EA, the 0.5, 1 and 2 hours after EA groups had a significant reduction in the protein expression of OX-42 (P<0.01), and immediately after EA, the 0.5 and 1 hour after EA groups had a significant reduction in the protein expression of P2X4 (P<0.01). CONCLUSION: EA at "Jiaji" points can significantly increase heat pain threshold and down-regulate the protein expression of OX-42 and P2X4 in the spinal cord of CCI rats. The analgesic effect can last for 2 h.
ABSTRACT
Objective To observe the influence of losartan on rats′blood pressure and myocardium.Methods To randomly divide 24 4-year-old spontaneously hypertensive male rats into 3 groups.Group A is given normal saline(NS);group B is given losartan 20 mg/kg in 4-week-old;group C is given the same dose in 1 2-week-old;To take another 4-week-old male wistar rats to form group D,feed NS served as normal comparison.Each group was given NS or losartan one time each day through intragastric administration for 4 weeks.Follow up 24 weeks after stopping the medicine.Rats’SBP were measured through tail cuff method respectively when at 4,8,12,16,20 and 24 weeks’ time.After 24 weeks,cut off the head to take the sample,the RVW/BW,HW/BW,LVW/BW were measured through weighing method.To observe the morphologic change of the cardiac muscles and measure the area of myocardium cell cross section through HE stain method.Ra-dioimmunoassay was used to measure the AngⅡand Aldo level of the blood plasma and myocardium.Results At the age of eight-week,the SBP of group A and C are higher than those of group D(P0.05).About LVW/BW,HW/BW and the ar-ea of myocardium cell cross section,group A increased significantly in comparison with group D (P<0.05),group B and C decreased in comparison with group A(P<0.05),group B decreased significantly in comparison with group C(P<0.05).Through the observation of the area of myocardial cell cross section under the microscopy,group A increased significantly in comparison with group D about myocardial cell fattened and the gap between cells are widened,the fibers of mesenchyma proliferates.group B and D are similar,group C is between group B and A.The level of AngⅡand Aldo in plasma and myocardium of group A increased significantly in comparison with group D (P<0.05),group B decreased significantly in comparison with group A and C(P<0.05).Conclusion To use losartan for a short time in trea-ting rats with prehypertension can get the after-effect of reducing blood pressure and anti-ventricular-remodeling.