Beneficial effect of T-type calcium channel blockers on endothelial function in patients with essential hypertension.

Abstract

Endothelial function is impaired in essential hypertension. T-type but not L-type voltage-gated Ca2+ channels were detected in the vascular endothelium. The purpose of the present study was to clarify the role of T-type Ca2+ channels in endothelial function. We studied flow-mediated vasodilation (FMD) and sublingual nitroglycerin (NTG)-induced vasodilation in the brachial artery. Forty patients with essential hypertension were randomly assigned to treatment with efonidipine, a T- and L-type Ca2+ channel blocker, or with nifedipine, an L-type Ca2+ channel blocker. Twenty healthy normotensive individuals were included as a control group. In patients with essential hypertension, FMD was attenuated and NTG was similar that of compared to healthy controls. After 12 weeks, the decrease in mean blood pressure in the efonidipine and nifedipine groups were similar. The endothelial function index, a ratio of FMD/NTG, was significantly increased by efonidipine (73 +/- 24 to 94 +/- 20%) but unchanged by nifedipine. Urinary excretion 8-hydroxy-2'-deoxyguanosine (8-OHdG) and serum malondialdehyde-modified low-density lipoprotein (LDL) were decreased by efonidipine but unchanged by nifedipine. These results suggest that a T-type Ca2+ channel blocker, but not an L-type Ca2+ channel blocker, may improve vascular endothelial dysfunction in patients with essential hypertension via a reduction in oxidative stress.

• Authors: Tetsuya Oshima, Ryoji Ozono, Yoko Yano, Yukihito Higashi, Hiroki Teragawa, Narimasa Miho, Takafumi Ishida, Mari Ishida, Masao Yoshizumi, Masayuki Kambe
• Journal: Hypertension research : official journal of the Japanese Society of Hypertension (Hypertens Res) Vol. 28 Issue 11 Pg. 889-94 (Nov 2005) ISSN: 0916-9636 [Print] England
• PMID: 16555577 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium Channel Blockers
• Dihydropyridines
• Nitrophenols
• Organophosphorus Compounds
• efonidipine
• Nifedipine

Topics

• Adult
• Aged
• Blood Flow Velocity (drug effects)
• Brachial Artery (drug effects)
• Calcium Channel Blockers (pharmacology, therapeutic use)
• Case-Control Studies
• Dihydropyridines (pharmacology, therapeutic use)
• Endothelial Cells (drug effects)
• Endothelium, Vascular (drug effects)
• Female
• Humans
• Hypertension (drug therapy, physiopathology)
• Male
• Middle Aged
• Nifedipine (pharmacology, therapeutic use)
• Nitrophenols (pharmacology, therapeutic use)
• Organophosphorus Compounds (pharmacology, therapeutic use)
• Vasodilation (drug effects)