ABSTRACT
BACKGROUND AND OBJECTIVES: The renin angiotensin system seems to play an important role in the development of cardiac and vascular hypertrophy in hypertension. The changes in pathology, and gene expressions of the angiotensin II receptor type 1A (ATIA) and angiotensin converting enzyme (ACE) were investigated in order to explore the effects of losartan in spontaneously hypertensive rat (SHR) models. MATERIALS AND METHODS: Twelve week-old male Wistar rats were grouped as follows: control (C) group, hypertension (H) group, and losartan (L) group in which SHR was treated with losartan (10 mg/kg/day). Western blot and reverse transcription-polymerase chain reaction analysis regarding seven genes such as endothelin-1, ACE, ATIA, neutrophil cytosolic factor, brain natriuretic peptide, troponin I, endothelial nitric oxide synthase were performed. RESULTS: Systolic blood pressure was significantly decreased in the L group compared with the H group in weeks 3 and 5. ACE and ATIA proteins in the L group were lower than H group in week 5. CONCLUSION: Losartan reduced blood pressure, cardiac hypertrophy and protein expressions of ACE and ATIA. Changes of protein expressions were more sensitive than changes in pathology. Further study is needed for the differing doses of losartan in SHR models.
Subject(s)
Humans , Male , Blood Pressure , Blotting, Western , Cardiomegaly , Cytosol , Endothelin-1 , Gene Expression , Hypertension , Hypertrophy , Losartan , Natriuretic Peptide, Brain , Neutrophils , Nitric Oxide Synthase Type III , Peptidyl-Dipeptidase A , Proteins , Rats, Inbred SHR , Rats, Wistar , Receptors, Angiotensin , Renin-Angiotensin System , Troponin IABSTRACT
BACKGROUND: Interfering RNA (iRNA) represents a recent breakthrough in effective blocking of the target genes in mammalian cells. Angiotensin-converting enzyme (ACE) has been shown to play an important role in the pathogenesis of hypertension. The purposes of this study were to investigate the effects on blood pressure, myocardial hypertrophy and gene expressions of iRNA targeting ACE. METHODS: Twelve week old male Wistar-Kyoto rats were grouped as follows: control group (C group), spontaneously hypertensive rat (SHR) group (H group), and ACE-iRNA group (A group) in which SHR was treated with recombinant lentiviral vectors carrying small hairpin RNA targeting ACE. Reverse transcription-polymerase chain reaction and western blot analysis of ACE, endothelin (ET)-1, angiotensin (AT) II receptor type 1A, neutrophil cytosolic factor, caspase 3, Bax, and Bcl-2 were performed in the heart tissues. Serum AT, ACE, and high sensitive-C reactive protein were estimated. RESULTS: Systolic blood pressure was significantly decreased in the A group compared with the H group in weeks 3 and 5. Serum AT level was significantly lower on day 1, weeks 3 and 5 after ACE-iRNA treatment. ACE protein contents were significantly lower after ACE-iRNA treatment in week 5. ET-1 and Bcl-2 protein contents were significantly lower after ACE-iRNA treatment in weeks 3 and 5. Bax protein contents were significantly lower after ACE-iRNA treatment in week 3. CONCLUSIONS: Recombinant lentiviral vectors carrying shRNA targeting ACE prevented hypertension. Serum AT and gene expressions such as ACE, ET-1, Bax, and Bcl-2 were significantly decreased after ACE-iRNA treatment.