Dietary flaxseed protects against ventricular fibrillation induced by ischemia-reperfusion in normal and hypercholesterolemic rabbits

Bradley P. Ander, Anna R. Weber, Penelope P. Rampersad, James S.C. Gilchrist, Grant N. Pierce, Anton Lukas

Research output: Contribution to journalArticle

100 Scopus citations

Abstract

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the (n-3) PUFA found in fish oils, exert antiarrhythmic effects during ischemia. Flaxseed is the richest plant source of another (n-3) PUFA, α-linolenic acid (ALA), yet its effects remain largely unknown. Our objective was to determine whether a flaxseed-rich diet is antiarrhythmic in normal and hypercholesterolemic rabbits. Male New Zealand White (NZW) rabbits (n = 14-16) were fed as follows: regular diet (REG group); diet containing 10% flaxseed (FLX group); 0.5% cholesterol (CHL group); or 0.5% cholesterol + 10% flaxseed (CHL/FLX group) for up to 16 wk. Plasma cholesterol was significantly elevated in the CHL and CHL/FLX groups. Plasma triglycerides were unchanged. ALA levels increased significantly in plasma and hearts of the FLX and CHL/FLX groups. After the feeding period, rabbit hearts were isolated and subjected to global ischemia (30 min) and reperfusion (45 min). Ventricular fibrillation (VF) occurred during ischemia in 33% of REG but in none of FLX hearts, and 28% of CHL but only 6% of CHL/FLX hearts. VF incidence during reperfusion was 28% and 26% in REG and FLX hearts, respectively. The incidence significantly increased to 64% in CHL hearts, and was significantly attenuated (18%) in CHL/FLX hearts. CHL markedly prolonged the QT interval, whereas FLX significantly shortened the QT interval and reduced arrhythmias in the FLX and CHL/FLX hearts. In vitro application of (n-3) PUFA shortened the action potential duration, an effect consistent with the QT data. This study demonstrates that dietary flaxseed exerts antiarrhythmic effects during ischemia-reperfusion in rabbit hearts, possibly through shortening of the action potential.

Original languageEnglish (US)
Pages (from-to)3250-3256
Number of pages7
JournalJournal of Nutrition
Volume134
Issue number12
StatePublished - Dec 1 2004
Externally publishedYes

Keywords

  • α-linolenic acid
  • (n-3) PUFA
  • Action potentials
  • Arrhythmias
  • Ion channels

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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    Ander, B. P., Weber, A. R., Rampersad, P. P., Gilchrist, J. S. C., Pierce, G. N., & Lukas, A. (2004). Dietary flaxseed protects against ventricular fibrillation induced by ischemia-reperfusion in normal and hypercholesterolemic rabbits. Journal of Nutrition, 134(12), 3250-3256.