Association Between Angiontension Ⅱ Type2Receptor Gene Polymorphism And Pedigreed Salt-sensitive Hypertension

Background：Essential hypertension is a common cardiovascular disease and it is one of main riskfactors which cause a variety of other diseases, especislly the heart blood-vessel.Thefinal conclusion of hypertensive pathogenesis was not clear, although people havemade tremendous efforts to explore the etiological factor of hypertension.Salt wasregard as one of the most important environment factors for a long time.Renin angiotensin aldosterone system, which has the greatest activity, is the mostimportant regulating system inside human body.It is one of the most important genesin rennin angiotensin aldosterone system （RAAS） that angiontension Ⅱ Type2Receptor （AT₂R） is the key receptor when RAAS is unusual.The final conclusion wasnot defined about the relationship between angiontension Ⅱ Type2Receptor （AT₂R）gene A1675G polymorphism and hypertension.Objective：1. To investigate the influence of sodium, potassium which caused hypertensionoccurred and development under diatary Intervention.And to investigate familycollecting of salt-sensitive hypertension.2. To investigate the frequency of angiontension Ⅱ Type2Receptor （AT₂R） geneA1675G and its relation to pedigreed salt-sensitive hypertension. Methods:One village is one spot center, and one family is one unit.Han people who was at thisvillage above five years was selected as participation.There were384eligibleparticipations.They were115proposita,269siblings and children.And they were193males and191females. Average age was35.3±12.7years.All participations offeredConsent Book.All pedigreeds, which were eligible selected were divided into twogroups,salt sensitive pedigreed group and non-salt sensitive pedigreedgroup,respectively,by blood pressure changes after diet intervention stages.At everystage,all participations received anthropometric measurement,blood pressuremeasurement by nil-sphygmomanometer.Urine sodium, urine potassium,urinecreatinin,blood triglycerides,blood cholesterol,blood sugar and other biochemistrywere measured at every diet stage.DNA was drawn out by low permeate hemolysisand salting-out technique.Angiontension Ⅱ Type2Receptor（AT₂R）A1675G genepolymorphism was identified by polymerase chaim reaction（PCR）and sequencing.Results:There were170salt sensitive cases and214non-salt sensitive cases after dietintervention.As proposita,there were62salt sensitive cases and53non-salt sensitivecases.There were significant difference in the number of salt sensitive siblings andchildren between salt sensitive proposita’s and non-salt-sensitive proposita’s（P＜0.05）.There was no significant difference in common data between salt sensitivegroup and non-salt sensitive group.There were significant differences in systolicpressure and mean arterial blood pressure at low salt diet stage and high salt diet stagebetween salt sensitive group and non-salt sensitive group（P＜0.05）.There weresignificant differences in carotid-radial pulse wave velocity（crPWV）at high salt dietstage and high salt fill potassium diet stage between salt sensitive group and non-saltsensitive group（P＜0.05）.AA was major gene type of （AT₂R） gene A1675G polymorphism of salt sensitivegroup.G allele was less in salt sensitive group. There were91cases of AA type（53.5%）,28cases of AG type（16.5%）and51cases of GG type（30.0%）of salt sensitivegroup and there were82cases of AA type（38.3%）,26cases of AG type（12.2%）and 106cases of GG type（49.5%）of non-salt sensitive group.There were significantdifference in AA type and A allele frequency of salt sensitive group compared withthat of non-salt sensitive group（P＜0.05）.There were76cases of AA type（52.4%）,26cases of AG type（17.9%）and43cases of GG type（29.7%）of siblings and children ofsalt sensitive proposita and there were36cases of AA type（29.0%）,16cases of AGtype（12.9%）and72cases of GG type（58.1%）of siblings and children of non-saltsensitive proposita.There were significant difference in AA type and A allelefrequency of siblings and children between salt sensitive proposita and non-saltsensitive proposita（P＜0.05）.There were significant differences in carotid-radial pulsewave velocity（crPWV）at high salt diet stage and high salt fill potassium diet stagebetween AA type of salt sensitive group and GG type of salt sensitive group （P＜0.05）.There were significant differences in express concentration of AT₂R at high saltdiet stage between AA type,AG type,GG type of salt sensitive group and non-saltsensitive group（P＜0.05）.There was negatively correlated between the crPWV of Saltsensitive AA gene and AT₂R expression concentration.Conclusion:1. Sodium is one of the most important environmental factors of hypertension occurdevelopment.2. Significantly family collecting is the character of salt sensitive hypertension.3. It is abnormal about activity of renin-angiotensin-aldosterone system （RAAS） ofsalt sensitive hypertension.4. There is relationship between AT₂R gene A1675G polymorphism and salt sensitivehypertension.1675G allele maybe one of the gene markers of salt sensitivehypertension.