Document Detail

Protection of retinal vasculature by losartan against apoptosis and vasculopathy in rats with spontaneous hypertension.
MedLine Citation:
PMID:  20051910     Owner:  NLM     Status:  MEDLINE    
OBJECTIVES: Retinal blood vessels may develop vasculopathy and apoptosis in response to hypertension. The present study was aimed at testing the role of losartan, a specific antagonist of angiotensin II receptor type 1 receptor in regulation of vascular apoptosis in retinal vasculature with hypertension. METHODS: Losartan potassium was administered to spontaneously hypertensive rats (SHR). Blood pressure was measured in SHR as well as normotensive Wistar-Kyoto rats (WKY). Eye fundus was examined in living animals and then tissue specimens were collected for histochemistry by hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL), immunohistochemistry and transmission electron microscopy. RESULTS: Losartan treatment for 4-8 weeks reduced blood pressure of SHR to the normal levels seen in WKY. The losartan-treated SHR showed marked improvement of retinal vascular morphology compared with untreated SHR. The retinal blood networks of the treated SHR developed lower degrees of vasculopathy and apoptosis. TUNEL and transmission electron microscopy also revealed that losartan exerted its protective effects not only on endothelial cells but on pericytes as well. The blood vessels of losartan-treated animals also showed decreased expression of bax with elevation of B-cell CLL/lymphoma 2. CONCLUSION: Treatment with losartan, a medicine that lowers blood pressure by blocking angiotensin II receptor type 1 receptor, can protect the retinal vasculature against hypertensive vascular injury by inhibiting apoptosis of vascular cells and by preventing hypertensive retinopathy.
Deye Yang; Mingying Zhang; Xiaoyan Huang; Fei Fang; Bixin Chen; Saibin Wang; Jianqiu Cai; Xiangxiang Shi; Jia Qu; Yong-Jian Geng
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of hypertension     Volume:  28     ISSN:  1473-5598     ISO Abbreviation:  J. Hypertens.     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-02-17     Completed Date:  2010-06-01     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  England    
Other Details:
Languages:  eng     Pagination:  510-9     Citation Subset:  IM    
The First Affiliated Hospital of Wenzhou Medical College, Wenzhou, China.
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MeSH Terms
Angiotensin II Type 1 Receptor Blockers / pharmacology*,  therapeutic use
Apoptosis / drug effects*
Blood Pressure / drug effects
Endothelium, Vascular / drug effects
Flow Cytometry
Hypertension / drug therapy*,  pathology
In Situ Nick-End Labeling
Losartan / pharmacology*,  therapeutic use
Rats, Inbred SHR
Rats, Inbred WKY
Retinal Vessels / drug effects*,  pathology
Umbilical Veins / drug effects
Vascular Diseases / prevention & control*
Reg. No./Substance:
0/Angiotensin II Type 1 Receptor Blockers; 114798-26-4/Losartan

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