肾脏花生四烯酸CYP羟化酶与高血压及肾功能关系的研究

肾脏花生四烯酸CYP羟化酶对肾功能及血压调节有重要作用，但作用方式不明。本项目用重橄傧喙夭《拘鳦YP4A1cDNA制成持久肾高效表达4A转基因大鼠模型，研究肾CYP羟化酶对血压及肾功能的影响；用反义CYP4A1cDNA阻断自发性高血压大鼠等肾CYP4A基因表达，进一步芯科湓诟哐狗⒉⒀沟鹘谥械淖饔煤投陨龉δ苡跋旒捌浠怼?.

Fan Zhang, Jiaqing Qian, Dao Wen Wang. Dept. of Internal Medicine and Gene Therapy Center, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, People's Rep. of China. ..Background: arachidonic acid (AA) Cytochrome P450 (CYP)-dependent hydroxylases (CYP 4a family) are dominant in kidneys and metabolize AA into w and w-1 hydroxyeicosatetraenoic acid (19/20-HETE). A growing body of evidence showed that the CYP 4a plays important roles in the formation and development of the hypertension, but considerable studies in differentl models provide paradoxical results. In order to confirm the real role of CYP 4a genes or 19/20-HETE in blood pressure regulation or the development of hypertension, we delivered CYP 4a1 cDNA into SD rats and spontaneous hypertensive rats (SHR) to overexpress CYP 4a1 both temporarily and persistently and to observe the effects of HETE on blood pressure. .Methods: CYP 4a1 cDNA was subcloned into pcDNA3.1 (in sense and antisense) to construct pcDNA×4a1 and pcDNA×anti4a1, and also into recombinant adeno-associated virus (rAAV) vector to get high titres of rAAV (2.5′1012 pfu/ml) containing CYP 4a1 cDNA via cotransfection and packge in 293 cells. Different constructs of CYP 4a1 cDNAs or rAAVs were injected into rat intravenously (2mg of plasmid DNA/Kg body weight or 1′1010 rAAV particles/rat) and then the tail blood pressure was measured weekly. .Results: The results showed that (1) pcDNA×4a1 delivery induced hypertension and blood pressure increased by 13±3 mmHg at week 2 after injection, and in contrast, pcDNA×anti4a1 induced hypotension (-16 mmHg at week 2). The changed blood pressures went up to normal at week 4; Very surprisingly, Northern and western Blot assay showed sense and antisense mRNA preferentially overexpressed in transferred rat kidneys; (2)rAAV×4a1delivery induced a persistent hypertension (increase of 15±2mmHg) in SD rats and rAAV×anti4a1 led a persistent a stable reduction in blood pressure by 20±2mmHg in SHR 3 weeks after injection..Conclusions: These findings lead the conclusions that CYP 4asubstantially contributes to the formation and development of hypertension, and also to the maintenance of the normal blood pressure. This study suggests that it is extremely valuble to investigate the relations between hypertension and CYP- AA hydroxylases in patients with essential hypertension and oue results also provide insights for development of new antihypertensive drugs or gene therapy of hypertension through inhibition of CYP-AA hydroxylases..