The Research Of The Mechanism Of ACE/ACE2 In HSPN Model Of Rabbits

Objective : To establish an animal model of Henoch-Schonlein purpura induced ov-albumin(OVA)in rabbits,and to provide pathogenesis for further study on pathogenesis of Henoch-Schonlein purpura.To explore the mechanism of angiotensin converting enzyme / angiotensin converting enzyme2 in rabbit Henoch-Schonlein purpura nephritis model.At the molecular level,the relationship between them in the occurrence and development of HSPN was discussed.Methods:Establishment of experimental animal model of allergic purpura in rabbits:20 rabbits were randomly divided into two groups: model group and control group(N=10).The model group was given the prescription traditional Chinese medicine decoction to drink once a day,1 ml each time for 3 weeks,The control group was given the same amount of physiological saline.In the model group,1 ml of emulsion solution was injected intraperitoneally on the day of the last feeding for 3 weeks.The control group was given the same amount of physiological saline intraperitoneal injection.7 days after the last intraperitoneal injection,model group rabbits were injected through the auricular vein with 10 mg / ml ovalbumin saline solution of 0.5ml.At the same time,shaving at the back and intradermal injection of 0.3% ovalbumin saline 1 ml at 5 points.The control group was given intradermal injection of physiological saline with the same method and dose.Observation and comparison of the general situation of the two groups after injection,Laboratory indexes were detected after 24 hours,and pathological results of skin and kidney tissues after three weeks were detected.Enzyme-Linked Immuno Sorbent Assay was used to detect the enzyme activity of ACE2,ACE in the blood serum of the auricular artery.Reverse Transcription-Polymerase Chain Reaction was used to extract RNA from the above mentioned kidney tissues and the expression levels of ACE2 m RNA and ACE m RNA were compared between the two groups.Results : Subcutaneous purple spots in 6 rabbits of the model group,There were significant differences between two groups in terms of blood viscosity,blood and urine routine Ig A、Ig G、C3、C4 and so on.The pathological features of the skin in the model group were edema of the dermis,capillary dilatation,hemorrhage,inflammatory cell infiltration and Ig A deposition in the vascular wall.Cortical edema,capillary dilatation,bleeding,inflammatory cell infiltration and Ig A deposition in vascular walls.Renal histopathological features were glomerular Mesangial thickening,Mesangial cell and matrix proliferation,cystic protein exudation and focal chronic glomerulonephritis with a large amount of immune complex deposition.Compared with the control group,the enzyme activity of ACE in serum of HSPN model was significantly higher than that of control group(P < 0.05),and the enzyme activity of ACE2 was significantly decreased(P < 0.05).ACE m RNA in renal tissue of HSPN model was significantly increased,ACE2 m RNA was significantly lower than that in control group(P < 0.05),and ACE/ACE2 m RNA ratio was increased.Conclusions:A stable allergic purpura animal model can be successfully simulated by using Chinese Medicine decoction,continuous OVA stimulation,intravenous and intradermal high dose OVA impact.During renal damage,the Ras system was activated abnormally.One of the main causes of renal damage in Henoch-Schonlein purpura was the increase of ACE expression,the decrease of ACE2 expression and the imbalance of ACE and ACE2 ratio.