| Objective To compare the differences and the effectiveness of wild alginate injection and arterio-venous shunt in the establishment of pulmonary hypertension rat model.Methods 30 male Sprague-Dawley(SD)rats aged 4 to 5 weeks were randomly divided into four groups:normal control group(group C),wild alginine injection group(group M),sham operation group(group N),arteriovenousshunt group(group S).28 days after modeling,they were examined by ultrasonography.On day 42,their hemodynamics(pulmonary arterial pressure,right ventricular pressure)were easured with a floating catheter.After euthanizing these mats,echocardiography was used to determine their right ventricular hypertrophy index.The changes of pulmonary arterial structure were observed by HE staining.The apoptosis of vascular endothelial cells was determined by TUNEL staining.The formation of pulmonary fibrosis was determined by masson and Sirius red staining.Iununohistochemistry and cell molecular experiments were used to verify the changes of relevant factors in protein level.Do the research on rats in all groups,eomparing the general situation and survival rate,changes of weight,pulmonary artery pressure(mPAP)and right ventricular pressure(RSVP),right ventricular hypertrophy index(RV/LVs),pulmonary vascular pathological morphological changes(using HE staining and image analysis system to observe the pathological changes of pulmonary arterioles morphology study),to observe the effect of succinic acid on the morphology,physiology,pathology,function and metabolism of rats in pulmonary hypertension model.Results The MCT model injected intraperitoneally showed the reduced activity gradually in different degrees,tired lying,less eating as these of the control group after 1 week and rough hairs,apparent decreased activity,weight loss,and even wheezing,nasal and lips cyanosis after 2-3 weeks.The rats in the arteriovenous shunt group had decreased activity,burnout and food intake in the first week after the shunt operation.The activity of the 2nd to 3rd week increased much more than these of the 1st week.The food intake increased slightly after the 2-3 weeks.They gradually appeared breathing,exercise reducing)nasal and lips cyanosis etc on the 4nd to 6nd week.The pulmonary arterial pressure in MCT model group and arteriovenous shunt group were significantly higher than that in control group and sham operation group at 6th week.The pulmonary vascular pathology all showed different degrees of moderate smooth muscle thickening.TUNEL staining showed that the apoptosis of pulmonary arterioles in MCT rats was increased,and the degree of right ventricular remodeling in arteriovenous shunt group was more obvious than that in wild alginine group.Lateral blood flow between the abdominal aorta to the inferior vena cava can be observed in the model group rats on the animal echocardiography,transverse flow rate of 1262±106mm/s5 showing arteriovenous Shunt construction is successful.The right ventricular SBP5 mean pulmonary arterial pressure,pulmonary artery SBP and pulmonary artery DBP in group M and the arteriovenous shunt group were significantly higher than the control group and the sham operation group(P<0.05);and there was no statistic difference in group M and the arteriovenous shunt group.(Figure 2).The right ventricular hypertrophy index of arteriovenous shunt group and wild lily group was significantly higher than that of control group and sham operation group.The right ventricular hypertrophy index of arteriovenous shunt group was greater than that of wild monocrotaline group.TUNEL staining showed that the apoptosis of pulmonary vascular endothelial cells increased in wild monocrotaline group,there was no obvious apoptosis of pulmonary vascular endothelial cells in rats of arteriovenous shunt group but increased apoptosis of vascular interstitial cells.HE staining showed that the pulmonary arterioles of the rats were significantly thickened and the infiltration of inflammatory cells in the local tissue was increased.?-SMA and Ki67 immunohistochemistry showed that the proliferation of pulmonary arterial smooth muscle cells was increased in monocrotaline group and arteriovenous shunt group.Conclusion The method of intravenous administration of monocrotaline and venous shunt are all effective methods to establish rat pulmonary hypertension model.The pulmonary arterial model established by the surgical method develops slowly,the model of pulmonary hypertension founded by monocrotaline injection grows rapidly.In addition,wild monocrotaline TUNEL staining was used to observe the increase of apoptosis in rat pulmonary arterial endothelial cells.Objective To investigate whether succinic acid couldexacerbate the early interstitialfibrosis of cardio-pulmonary arteries induced by monocrotaline in rat model of pulmonary hypertension,and explore its pathological and molecular mechanisms.Methods 30 healthy male SD rats aged 4 to 5 weeks,weighing 120-180g,were randomly divided into control group(C group),monocrotaline group(M group),monocrotaline and suecinie acid group(M+5 group),with 10 rats in each group.M group and M+S group were subjected to intraperitoneally injection with monocrotaline in 60 mg/kg,while group C was intraperitoneally injected with equal volume of saline.M+S group was intraperitoneally injected with succinic acid in 2mg/kg for 30min,and lmg/kg succinate acid was injected intraperitoneally for 4 weeks.The rats in the control group and M group were injected with equal volume of saline,lasting 4 weeks.After 4 weeks,hemodynamics,including pulmonary arterial pressure(mPAP),right ventricular pressure(RVSP),systolic blood pressure(SBP)and diastolic blood pressure(DBP)of pulmonary artery,were measured by floating eatheter in all groups.The right ventricular hypertrophy index was measured after euthanasia.H&E staining,Masson staining and Sirius red staining wereconducted to detect the remodeling of arteriole in the heart and lung tissue.western Blot and immunohistochemistry were conducted to examine the protein level of Angll,PDGF-BB,and FGF2 in the pulmonary hypertension rat model.Results The rats in the MCT model group and the SUC intervention group both showed decreased activity,sleepiness and poor appetite.Lips cyanosis and shortness of breath appear earlier in the SUC intervention rats.Hemodynamic examinationexhibitedthat indexes,including mPAP,RVSP,SBP and DBP of pulmonary artery,were significantly higher in M group and M+S group than those in control group(**P<0.01).All above hemodynamic indexes in M+S group were slightly but significantly higher than those in group M(*P<0.05).H&E staining showed slight thickening of the small arteries in the M group,the degree of thickening of the arterial wall of M+S group was more obvious than that of the M group,and the infiltration of inflammatory cells in the local myocardium increased.The right ventricular hypertrophy index of M group and M+S group was significantly higher than that of control group(*P<0.05),whereas the index of M+S group was significantly higher than that of M group(*P<0.05).The thickness of the minor arteries in the M+S group was significantly higher than that in the M group.Sirius red staining and Masson staining showed abnormal proliferation of collagen fibers in the interstitial cells of the M+S group,and no abnormal collagen fibers in the M group.The results of immunohistochemistry showed that Ang ? was significantly deposited in the intercellular space of the M+S group,and the Ang ?in the M group was slightly deposited in the local interstitial cells.No obvious deposition was observed in the control group.Changes of FGF-2 and PDGF-BB expression levels in M+S group and M group were significantly higher than those in control group,and the expression of FGF-2 and PDGF-BB protein in M+S group increased significantly and the gray scale of band enhanced.Conclusion Succinic acid can inhibit the formation of early fibrosis of cardiopulmonary arterioles in rats with pulmonary hypertension induced by monocrotaline.The mechanism may be due to the specific activation of G protein-coupled receptor 91,thereby regulating the expression of FGF-2 and PDGF-BB in the body,and eventually lead to increased expression of angiotensin ?(Angll),causing intrahepatic interstitial fibrosis formation. |
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