The Study Of Depressed Arterial Baroreflex's Effection On Telomere Length In Kidney Of Rat

Arterial baroreflex (ABR) is a very important mechanism in the regulation of cardiovascular activities, maintaining blood pressure stable and limiting blood pressure variability (BPV) to a given extent is its main physiological function. Baroreflex sensitivity can predict bad arrhythmia and cardiac mortality after myocardial infarction. Our former study proved that depressed ABR related to end-organ damage in SHR and the artifical interruption of ABR can also induce severe end-organ damage.Hypertension is a major age-related disease with a higher incidence among cardiovascular diseases and its explicit mechanism is unknown now. ABR function is impaired in hypertension, it may play a role in the develop of hypertension or the result of hypertension. Some researchers develop the notion that proliferation may be an important component in the pathogenesis of hypertension. It's well known that telomere is related to proliferated diseases and more and more people recently, discover that telomere is associated with cardiovascular diseases. Telomere serves as a mitotic clock. The proposal of 'telomere theory' might bring some novel hint for people that age-dependent telomere attrition might participate in pathological proceeding of EH,even can result in it. Due to 'telomere theory', cell proliferation result in telomere shortening. Later study have observed that telomeres of SHR newborns are significantly shorter than those normotensive. We can presume that heredity is the determinant of telomere length in newborn, the accelerated biologic aging participates in the development of hypertension and end organ damage, displaying through short telomeres. Concerning impaired ABR in hyperhension , its might proliferation with the study on telomere, maybe there is some association between impaired ABR and telomere in hypertension. The studies on mechanism of depressed ABR concentrate on reflex arc and its might abnormal centre or periphery mechanisms. The aim of this study is to investigate whether depressed ABR can affect on telomere length in kidney of rats, meanwhile we explore the possible influential factors on telomere length in hemodynamics.We utilized SHR-SP and SAD two animal models which represent defected baroreflection, WKY and SAD sham operation for the same old are the control groups. We employ our department previous method to detect the hemodynamics. Telomere length was evaluated by measuring the length of the terminal restriction fragment (TRF) through Southern blotting in kidney for the following studyings: 1.whether defected ABR, high BPV or gender can affect telomere length in SHR-SP; 2. whether defected ABR through SAD operation can affecttelomere length in different periods.The main findings of this study are as followings:1. In the model of SHR-SP, telomeres length are all shorter than WKY for the same old, the result accord with other people's opinion that the telomere length in kidney of SHR are shorter than the normal blood pressure. TRF length is negatively correlated with SBPV and DBPV in male rats, this finding does not hold for female rats; no correlations were found between telomere length and other hemodynamics indices including BRS, SBP, DBP, HP and MAP. In addition, telomere lengths are longer in female rats than age-matched male; and younger rats have longer telomere lengths.2. In the model of SAD, no differences between TRF values in the rats of 4 weeks after operation and the control rats are found. This study also finds no significant difference between the rats of 35 weeks after operation and the sham operation group; The young rats have longer telomere than the old.Conclusion: 1. Telomere length in kidney of SHR-SP are shorter than WKY. Defected ABR in SHR-SP doesn't affect the length of telomere in itself, SBPV and DBPV are negative with telomere length in male SHR-SP, this result does not exist in female rats. Whether telomere attrition is the result or cause of high blood pressure variability needs further study. 2. In SHR-SP, telomere length are different with genders,...