ObjectiveTo investigate the expression of extracellular signalregulated kinase (ERK) and p38 mitogenactivated protein kinase （p38 MAPK） in autogenous vein grafts during vascular remodeling.MethodsAn autogenous vein graft model was established by transplanting the right jugular vein to infrarenal abdominal aorta in 80 Wistar rats. Vein graft samples were harvested 6 hours, 24 hours, 3 days, 7 days, 2 weeks, 4 weeks, 6 weeks and 8 weeks after surgery. Gene expression of ERK and p38 MAPK was measured by reverse transcriptionPCR. Western blot was used to detect the expression of protein products and phosphorylation protein products of ERK and p38 MAPK. Apoptosis of vascular smooth muscle cells (VSMCs) was determined by TUNEL. Proliferating cell nuclear antigen(PCNA) of VSMCs also was studied.ResultsThe expression of ERK1 mRNA and p38 MAPK mRNA increased considerably after surgery. ERK1 mRNA reached the peak on the 7th day 〔（33.2±14.2）%, P＜0.01〕, but p38 MAPK mRNA reached the peak on the second week after surgery 〔(58.8±26.2）%, P＜0.01〕. The expression of ERK1/2 detected by western blot reached the peak during 1 to 2 weeks and decreased gradually to normal level 6 weeks after surgery. The expression of p38 MAPK reached the peak during 2 to 4 weeks and decreased to 1/4 to 1/2fold 8 weeks after surgery. There was a positive relationship between ERK1 and PCNA(r=0.759 6，P＜0.01) and a positive relationship between p38 MAPK and apoptosis(r=0.892 2，P＜0.01). ConclusionActivation of MAPK system exists in autogenous vein grafts and it may become a new target for the therapy of stenosis after vein grafts.
Objective By observation of the diameter, progression rate, wall thickness, and the opening angle of the abnormal aortic of abdominal aortic aneurysm (AAA) in rats, to observe the effect of saturated hydrogen saline on residual strain of AAA rats, and to investigate its inhibition effect on AAA formation. Methods Twenty healthy male Sprague Dawley rats (weighing, 200-220 g) were randomly divided into 2 groups, which was made the AAA model by infiltration of the abdominal arota with 0.5 mol/L calcium chloride. Saturated hydrogen saline (5 mL/kg) or saline (5 mL/kg) was injected intraperitoneally in the experimental group or control group respectively, every day for 28 days. At 28 days, the diameter, progression rate, wall thickness, and opening angle of the abnormal aorta were mearsured. The aortic tissue was harvested for histological examination (HE staining and aldehyde-fuchsin staining). Results At 28 days after operation, the diameter of abnormal aorta in 2 groups were significantly higher than preoperative ones (P lt; 0.05), the progression rate in experimental group (65% ± 15%) was significantly lower than that in control group (128% ± 54%) (t=3.611, P=0.005). The opening angle and the wall thickness in experimental group were (88.78 ± 29.20)° and (0.14 ± 0.03) mm respectively, had significant differences when compared with the values in control group [(44.23 ± 28.52)° and (0.36 ± 0.05) mm respectively] (P lt; 0.01). The integrity and continuity of the aortic wall in experimental group were superior to that in the control group. Compared with the control group, the injury of elastic fiber in aortic wall and the infiltration of inflammation were all reduced. Conclusion Saturated hydrogen saline can maintain good mechanical properties and reduce dilatation of the aorta by increasing residual strain and reducing the remodeling of it.
Objective To observe the protective effects of simvastatin at different stages on monocrotaline (MCT) induced pulmonary arteral hypertension (PAH) in rats and evaluate the early preventive effect of simvastatin. Methods Twenty-four male SD rats were randomized into a control group, a PAH group, an early intervention group, and a late intervention group, with 6 rats in each group. The rats in the control group received intraperitoneal injection of normal saline (NS) on d0. The rats in the PAH group received one-off intraperitoneal injection of MCT (50 mg/kg) on d0. The rats in the early intervention group were pretreated with oral gavage of simvastatin (20 mg·kg–1·d–1)(d–7––1) before the intraperitoneal one-off injection of MCT (50 mg/kg, d0) and continued with oral gavage of simvastatin for 14 days (d1~14). The rats in the late intervention group received one-off intraperitoneal injection of MCT (50 mg/kg)(d0) and oral gavage of simvastatin (20 mg·kg–1·d–1) for the next 21 days (d15~35). Thirty-five days after the MCT injection (d36), mean pulmonary arterial pressure (mPAP) and right ventricular systolic pressure (RVSP) were measured by right heart catheter. Then the rats were sacrificed for separating the heart and lung, the right ventricular hypertrophy index (RVHI) and percentage of small pulmonary arteries media thickness (WT%), the inflammation score around the small pulmonary arterial were recorded. Results Compared with those in the PAH group, RVSP, mPAP, RVHI and WT% in two simvastatin interventiongroups got much better (P＜0.01), and the inflammation score around the small pulmonary arterial declined (P＜0.05). Compared with those in the late intervention group, RVSP, mPAP in the early intervention group improved (P＜0.05) and WT% decreased more significantly (P＜0.01). However RVHI and the inflammation score around the small pulmonary arterial were not different between two simvastatin intervention groups. Conclusions Both early intervention and late intervention with simvastatin can reduce RVSP, mPAP and WT% in MCT induced PAH rats. Compared with later intervention, early intervention can prevent PAH more remarkably.