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Objective:To invesgate the correlation between Angiotensin converting enzyme(ACE) gene polymorphism and Henoch-Schonlein purpura nephritis(HSPN) in children. Methods:According to the clinical features,pathological changes,48 HSPN children have been devided into 4 clinical types,Uab,I-GH,R-GH and NS type,and Ⅱ-Ⅳ 3 histological degrees respectively.The correlations between serum ACE level,ACE gene polymorphism and clinical presentation,pathlogical changs,effect to therapy were analyzed.Results:In the 48 patients,35(72.9%),4(8.3%),4(8.3%) and 5(10.5%) patients belonged to Uab type,I-GH type,R-GH type and NS type respectively.20(41.7%),19((39.6%)) and 9(18.7%) patients belonged to Ⅱ,Ⅲ and Ⅳ histological degrees respectively.5 patients had DD genotype,25 patients had ID genotype and 18 patients had II genotype.The mean serum ACE level of DD genotype patients was(39.60?11.40)U/L,which was significant higher than that of ID genotype patients[(24.29?11.62)(U/L) and II genotype patients(4.49?11.41)U/L](P
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Objective To establish a rapid and accurate analysis method for food-derived ACE inhibitory peptides activity in vitro.Methods Reaction time of ACE and substrate was by measuring the hippuric acid liberated in the ACE reaction mixture at regular intervals;An optimal RP-HPLC method to measure food-derived ACE inhibitory peptides activity in vitro was set up.The hippuric acid from ACE reaction mixture(sea cucumber peptides were regarded as ACE inhibitor) was estimated by Zorbax SB-C_(18) analytical column with acetonitrile and ultrapure water as mobile phase.Results The reaction time of ACE with substrate was determined at sixty minutes;The elution was carried out with the ratio of acetonitrile to ultrapure water was 1:1(0.1%TFA) at a flow rate of 0.4 mL?min~(-1).The ahsorbance of the eluent was monitored at 228 nm,and column temperature was 25℃.The relationship between hippuric acid concentration and peak area exhibited a good linearity in the concentration ranges of 0～200?g?mL~(-1) and 200～800?g?mL~(-1).The RP-HPLC method was further validated by captopril,the oyster hydrolysate and the anchovy hydrolysate.Conclusion The method has been proved to be convenient,accurate and suitable for the analysis of foodderived ACE inhibitory peptides activity in vitro.