Skip to content
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Publication Details
AFRICAN RESEARCH NEXUS
SHINING A SPOTLIGHT ON AFRICAN RESEARCH
medicine
Calcitriol protects renovascular function in hypertension by down-regulating angiotensin II type 1 receptors and reducing oxidative stress
European Heart Journal, Volume 33, No. 23, Year 2012
Notification
URL copied to clipboard!
Description
Aims The present study investigated whether or not calcitriol, an active form of vitamin D, protects against renovascular dysfunction in hypertension and, if so, whether or not such protection alters the expression of key proteins involved in that dysfunction. Methods and resultsChanges in isometric tension showed that the impaired endothelium-dependent relaxations in renal arteries of hypertensive patients were enhanced by 12 h in vitro treatment with calcitriol. Dihydroethidium fluorescence revealed an elevated level of reactive oxygen species (ROS) in these arteries which was reduced by calcitriol. Immunofluorescence showed that calcitriol treatment reduced the expression of AT1R, NOX-2, NOX-4, and p67phox and increased that of superoxide dismutase (SOD)-1. Twelve-hour exposure to calcitriol prevented angiotensin (Ang) II-induced increases in ROS and the over-expression of NOX-2, NOX-4, and p67phox in renal arteries from normotensive patients. A specific antagonist of the human vitamin D receptor (VDR), TEI-9647, abolished these effects of calcitriol. Both in vitro exposure to and chronic in vivo administration of calcitriol enhanced relaxations to acetylcholine and abolished exaggerated endothelium-dependent contractions in renal arteries of normotensive rats pre-exposed to Ang II or harvested from spontaneously hypertensive rats (SHR). Reactive oxygen species levels and expressions of AT1R, NAD(P)H oxidase subunits, SOD-1, and SOD-2 in SHR arteries were normalized by the chronic treatment with calcitriol.ConclusionIn vivo and in vitro activation of VDR with calcitriol improves endothelial function by normalizing the expressions of AT1R and radical generating and scavenging enzymes and thus preventing ROS over-production. The present findings suggest that calcitriol is effective in preserving endothelial function in hypertension. © 2012 The Author.
Authors & Co-Authors
Dong, Jinghui
Hong Kong, Hong Kong
Chinese University of Hong Kong
China, Shijiazhuang
Hebei Medical University
Wong, Siu Ling
Hong Kong, Hong Kong
Chinese University of Hong Kong
Lau, Chi Wai
Hong Kong, Hong Kong
Chinese University of Hong Kong
Lee, Hung Kay
Hong Kong, Hong Kong
Chinese University of Hong Kong
Ng, Chi Fai
Hong Kong, Hong Kong
Chinese University of Hong Kong
Zhang, Lihong
Hong Kong, Hong Kong
Chinese University of Hong Kong
Yao, Xiaoqiang
Hong Kong, Hong Kong
Chinese University of Hong Kong
Chen, Zhen Yu
Hong Kong, Hong Kong
Chinese University of Hong Kong
Vanhoutte, Paul M.
Hong Kong
The University of Hong Kong Li ka Shing Faculty of Medicine
Saudi Arabia, Riyadh
King Saud University
Huang, Yu
Hong Kong, Hong Kong
Chinese University of Hong Kong
Statistics
Citations: 171
Authors: 10
Affiliations: 4
Identifiers
Doi:
10.1093/eurheartj/ehr459
ISSN:
0195668X
e-ISSN:
15229645
Research Areas
Noncommunicable Diseases