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

Tetsuya Oshima1, Ryoji Ozono, Yoko Yano

  • 1Department of Clinical Laboratory Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan. teto@hiroshima-u.ac.jp

Hypertension Research : Official Journal of the Japanese Society of Hypertension
|March 25, 2006
PubMed

Insights

T-type calcium channel blockers, unlike L-type blockers, significantly improved endothelial function in essential hypertension patients. Efonidipine reduced oxidative stress markers, suggesting a novel therapeutic approach for hypertension-related vascular dysfunction.

Area of Science:

  • Cardiovascular Medicine
  • Vascular Biology
  • Pharmacology

Background:

  • Essential hypertension is characterized by impaired endothelial function.
  • Voltage-gated T-type Ca2+ channels, but not L-type, are present in the vascular endothelium.

Purpose of the Study:

  • To investigate the role of T-type Ca2+ channels in endothelial dysfunction in essential hypertension.
  • To compare the effects of a T- and L-type Ca2+ channel blocker (efonidipine) versus an L-type Ca2+ channel blocker (nifedipine) on endothelial function.

Main Methods:

  • Flow-mediated vasodilation (FMD) and nitroglycerin (NTG)-induced vasodilation were assessed in 40 hypertensive patients and 20 controls.
  • Patients received either efonidipine or nifedipine for 12 weeks.
  • Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and serum malondialdehyde-modified LDL were measured.

Main Results:

  • Hypertensive patients showed attenuated FMD compared to controls.
  • Both efonidipine and nifedipine similarly reduced mean blood pressure.
  • Efonidipine significantly improved the endothelial function index (FMD/NTG) and reduced oxidative stress markers (8-OHdG, modified LDL), while nifedipine did not.

Conclusions:

  • T-type Ca2+ channel blockade, exemplified by efonidipine, may improve endothelial dysfunction in essential hypertension.
  • The improvement in endothelial function by efonidipine appears linked to a reduction in oxidative stress.
  • L-type Ca2+ channel blockade alone may not be sufficient to restore endothelial function in this patient group.

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