title: Prehypertensive treatment with losartan, however not amlodipine, leads to long-term effects on blood pressure and reduces the risk of stroke in spontaneously hypertensive stroke-prone rats.
abstract: The current study investigated the efficacy of losartan and amlodipine in protecting spontaneously hypertensive stroke-prone (SHRSP) rats against the risk of stroke. SHRSP rats were administered losartan, amlodipine or the vehicle for 6 weeks. There were no significant differences in systolic blood pressure (SBP) in rats treated with losartan or amlodipine, however, following drug withdrawal, rats treated with losartan maintained reduced SBP for a longer time compared with rats treated with amlodipine. In addition, rats treated with losartan exhibited thinner vascular walls and improved systolic and diastolic function. Clinical stroke scores in the losartan group were significantly reduced compared with those in the amlodipine and vehicle groups. However, rats treated with losartan exhibited higher levels of angiotensin II and lower levels of aldosterone in the serum and brain cortex compared with the vehicle and amlodipine-treated rats. Furthermore, losartan significantly reduced the abnormal expression of angiotensin II receptors type 1 and 2 in SHRSP rats, whilst amlodipine did not. These results suggest that losartan may be more efficacious than amlodipine in ameliorating blood pressure deterioration and reducing stroke risk in SHRSP rats via regulation of the renin angiotensin system.
authors.affiliation: Department of Cardiology, The First Clinical Medical College of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China.
authors.forename: Liangmin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, The First Clinical Medical College of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China.
authors.forename: Dehua
authors.initials: D
authors.lastname: He
authors.affiliation: Department of Cardiology, The First Clinical Medical College of Fujian Medical University, Fuzhou, Fujian 350005, P.R. China.
authors.forename: Jinxiu
authors.initials: J
authors.lastname: Lin
mesh_terms: D017311:Amlodipine / Q000008:administration & dosage*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D019808:Losartan / Q000008:administration & dosage*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D044140:Receptor, Angiotensin, Type 1 / Q000096:biosynthesis; D044139:Receptor, Angiotensin, Type 2 / Q000096:biosynthesis; D012307:Risk Factors; D020521:Stroke / Q000188:drug therapy* / Q000473:pathology / Q000517:prevention & control
chemical_list: D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D017311:Amlodipine; D019808:Losartan