Dietary docosahexaenoic acid protects against N-methyl-N-nitrosourea-induced retinal degeneration in rats

Exp Eye Res. 2003 Aug;77(2):167-73. doi: 10.1016/s0014-4835(03)00114-3.


The effect of dietary intake of specific types of fatty acids on retinal degeneration due to N-methyl-N-nitrosourea (MNU)-induced photoreceptor cell apoptosis was evaluated. Fifty-day-old female Sprague-Dawley rats were given a single intraperitoneal injection of 50 mg kg(-1) body weight of MNU, and were then switched to one of five different diets containing the following fatty acids at the following weight percentages: 10% linoleic acid (LA); 9.5% palmitic acid (PA) and 0.5% LA; 9.5% eicosapentaenoic acid (EPA) and 0.5% LA; 4.75% EPA, 4.75% docosahexaenoic acid (DHA) and 0.5% LA; or 9.5% DHA and 0.5% LA. When rats developed MNU-induced mammary tumors with a diameter of > or =1 cm, or at the termination of the experiment (20 weeks after MNU injection), retinal tissue samples were obtained and examined. Incidence and severity of retinal damage were compared by histologic examination. MNU-induced retinal degeneration was prevented in rats fed the diet containing 9.5% DHA (4.75% DHA was less effective), whereas it was accelerated in rats fed the 10% LA diet. Over the course of the 20-week experimental period, the fatty acid composition of serum reflected differences in dietary fatty acids. The present results indicate that a diet containing 9.5% DHA can counteract MNU retinotoxicity in the rat retina. DHA may play a role in protection against MNU-induced photoreceptor cell apoptosis in the rat retina.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylating Agents / toxicity*
  • Animals
  • Apoptosis / drug effects
  • Cell Survival
  • Docosahexaenoic Acids / administration & dosage*
  • Female
  • Mammary Neoplasms, Animal / chemically induced
  • Mammary Neoplasms, Animal / pathology
  • Methylnitrosourea / toxicity*
  • Photoreceptor Cells, Vertebrate / cytology
  • Rats
  • Rats, Sprague-Dawley
  • Retinal Degeneration / chemically induced
  • Retinal Degeneration / diet therapy
  • Retinal Degeneration / prevention & control*


  • Alkylating Agents
  • Docosahexaenoic Acids
  • Methylnitrosourea