gms | German Medical Science

27. Wissenschaftlicher Kongress der Deutschen Hochdruckliga

Deutsche Liga zur Bekämpfung des hohen Blutdrucks – Deutsche Hypertonie Gesellschaft e. V.

26. bis 29.11.2003, Bonn

Disparate Effects of Vitamin C and N-Acetylcysteine on Vascular Function in Subjects with Essential Hypertension

Unterschiedliche Effekte von Vitamin C und N-Acetylzystein auf die Gefäßfunktion von Patienten mit essentieller Hypertonie

Meeting Abstract (Hypertonie 2003)

  • M. Schneider - Universität Erlangen/Nürnberg (Nürnberg, D)
  • B. Schmidt - Universität Erlangen/Nürnberg (Nürnberg, D)
  • S. John - Universität Erlangen/Nürnberg (Nürnberg, D)
  • R.E. Schmieder - Universität Erlangen/Nürnberg (Nürnberg, D)
  • S. Oehmer - Universität Erlangen/Nürnberg (Nürnberg, D)
  • T. Schwarz - Universität Erlangen/Nürnberg (Nürnberg, D)

Hypertonie 2003. 27. Wissenschaftlicher Kongress der Deutschen Hochdruckliga. Bonn, 26.-29.11.2003. Düsseldorf, Köln: German Medical Science; 2004. Doc03hochP57

The electronic version of this article is the complete one and can be found online at:

Published: November 11, 2004

© 2004 Schneider et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Oxidative stress is increased in the vasculature of subjects with essential hypertension (EH). So far, the most effective agent for the in vivo detection of oxidative stress by intraarterial administration has not been determined. We compared the influence of the most commonly used antioxidants vitamin C (VITC) versus N-Acetylcystein (NAC) on endothelium-dependent (EDV) and -independent (EIV), nitric oxide mediated vasodilation in subjects with EH.


In a cross-over designed, randomized study, the effect of the acute intraarterial administration of VITC (18mg/min) or NAC (48mg/min) on vascular function in 15 subjects with EH and in 15 normotensive controls was examined. The other agent was used on a second examination date at least one week apart. Vascular function was determined as forearm blood flow (FBF) measured by plethysmography in response to the intraarterial administration of acetylcholine (ACH for EDV) and nitroprusside (NP for EIV) in doses of 12 and 48 mg/min and 32 and 128 mmol/min, respectively.


At baseline, subjects with EH had impaired EDV (D%FBF to ACH 48 mg/min: 319±132 vs 489±185 in controls; p=0.02) while EIV was similar to controls (D%FBF to NP 128 mmol/min: 383±162 vs 503±196 in controls; n.s.). Intraarterial administration of VITC improved EDV in EH (before 319±133 vs after 406±191, p=0.05). In contrast to VITC, treatment with intraarterial NAC did not affect EDV (before 325±146 vs after 338±112, n.s.).


VITC improves EDV in subjects with EH while NAC had no effect on vascular function. Thus, in future trials assessing oxidative stress in the forearm vasculature of subjects with essential hypertension, VITC should be used.