The Study Of Associations Between Single Nucletide Polymorphisms Of Angiotension Gene And Renin Gene And Cerebral Infarction

Object: Cerebrovascular disease with high incidence,high case fatality and high mutilation rate, is one of three most heavy deadly causes, as well as cardiac disease and malignant tumor. As the investigation of analysis epidemicology indicated, the risk factors of stroke could be divided into the interferable and the uninterferable. The interferable ones,which are the targets of the primary prevention for stroke, include hypertension, cardiac diseases, diabetes, blood-fat dysfunction, high homocysteic acidemia, smoking, excessive drinking, obesity, and so on. The uninterferable risk factors include age, gender, race, genetic factors, and etc. The incidence of stroke differs in different races. People with positive family history are more sensitive to stroke than others without family history. Currently the study on the pathogenesy of stroke chiefly concentrates on molecular genetics. Hypertension is the capital risk factor of stroke. The renin-angiotensin system(RAS) plays the first fiddle in the regulation of human blood pressure. In our experiment, based on the genetic backgrounds of Northern China, We studied whether the single nucletide polymorphisms(SNPs) of angiotensin(AGT) gene and renin(REN) gene were associated with essential hypetension(EH) and cerebral infarction(CI) in Chinese, and furtherly discussed the mechanisms of the occurrence of CI.Methods:⑴82 cases as crowd control group and 78 cases as essential hypertension(EH) group were selected from the population in the investigation of epidemic diseases in HeBei Province, while 82 patients with CI in hospital were collected from the 2th hospital of Hebei Medical University.⑵the general states(age, gender) of objects selected were investigated and recorded, as well as the history of hypertension, the history of diabetes,smoking history, and drinking history. Meanwhile the biochemical indicators including fasting blood glucose, plasma total cholesterol(TC), high density lipoprotein(HDL-C), and triglyceride(TG) were detected and recorded.⑶Genome DNA of the objects was isolated from peripheral venous blood with the classic alcohol phenyl-trichlormethane method.⑷Interesting fragments were amplified by polymerase chain reaction. All PCR products were observed by agarose gel electrophoresis and then analyzed.⑸PCR products were digested by restriction enzymes and analyzed after eletrophoresis. Five mutations respectively at 235 from M to T(T704C), 174 from T to M(C521T), -20 from A to C, -6 from G to A of AGT gene and 10631 from A to G of REN gene were determined in objects screened by a combination of polymerase chain reaction(PCR) amplification and restriction fragament length polymorphism(RFLP).⑹Some samples selected at random were sequenced to prove the products digested by incision enzymes. Shanghai bioengineering technical service limited company took charge of the sequencing.⑺Correlation analysis: measurement data were presented in mean±stardard deviation type( x±s), we employed u-test in group comparison.χ2 test was used in group comparison of enumeration data. Association study was performed to analyze the relationship between genotypes and alleles and EH and CI. Logistic regression was adopted to adjusted the bias of some siginficant stroke risk factors.Results:⑴EH group to crowd control group: Distributions of genotype and allele of the sites M235T and T174M of AGT were significantly different in the contol group and EH group. The frequencies of 235TT genotype and 235T allele in EH group were respectively 57.69%, 76.28%, higher than in the control group(35.37%, 48.78%, P<0.05); compared with the control group, the genotypes of 174TM and 174MM in EH group was lower (14.10%vs26.83%, P<0.05). The frequencies of 174M allele in EH group and the control group were 7.05%, 14.63% and the difference was also significant.The polymorphisms in other sites(G-6A, A-20C of AGT gene and A10631G of REN gene) examined in our study differed insignificantly in the two groups.⑵CI group to crowd control group: Distributions of genotypes of the sites M235T of AGT gene and A10631G of REN gene were significantly different between crowd control group and CI group. The frequencies of 235TT genotype (53.66%)and 235T allele (70.12%) in CI group were higher than in crowd control group. The frequencies of genotypes AA, AG, GG of 10631 site in REN gene in CI group were 29.27%, 60.98%, 9.76%, in control group 13.41%, 84.15%, 2.40%, very different from each other. The distributions of 10631A allele in CI group and crowd control group were not different.⑶Comparison of two subgroups in CI group: The distributions of M235T site of AGT gene in normotensive subgroup and hypertensive subgroup out of CI group were not different( P=0.591,P=0.898).⑷When taking plasma TC, TG, smoking and drinking history and other dangerous factors into consideration, The Logistic regression analysis showed drinking history was a protective factor(OR 0.43, P=0.0345)for CI. The other factors including the polymophisms of M235T in AGT gene and A10631G in REN gene couldnot be viewed as independant dangerous or protective factors for CI in the regression analysis.Conclusions:⑴The polymorphisms of M235T and T174M of AGT gene were associated with EH. It was possible that one with 235T or 235TT genotype was sensitive to EH while with 174M allele immune to EH.⑵The polymorphisms of M235T in AGT gene and A10631G in REN gene were associated with CI. Probably the 235M allele did not bring on CI because it contributed to hypetension.⑶The polymorphisms at the sites of G-6A, A-20C in AGT gene and A10631G in REN gene maybe have nothing with the occurrence of EH.⑷The polymorphisms at the sites of G-6A, A-20C, T174M in AGT gene maybe have nothing with the occurrence of CI.⑸Responsible drinking may prevent the occurrence of CI.