Effects of dietary supplementation with cod-liver oil on endothelium-dependent responses in porcine coronary arteries.

To study the effect of dietary supplementation with fish oil on endothelium-dependent responses, Yorkshire pigs were maintained on a normal diet or on a low (0.6 ml/kg/day) or a high (1.0 ml/kg/day) dose of cod-liver oil for 4 weeks. Endothelium-dependent responses were examined in vitro in rings of proximal left anterior descending coronary arteries taken from control and treated animals studied in parallel. Endothelium-dependent relaxations in response to bradykinin, serotonin, adenosine diphosphate, and thrombin were facilitated in arteries from treated but not in those from control animals, whereas the relaxations in response to A23187 were unaltered. The facilitated relaxations were not altered by indomethacin but significantly inhibited by methylene blue. Aggregating platelets from control and treated pigs induced comparable, facilitated endothelium-dependent relaxations in rings taken from treated pigs. The platelet-induced contractions were significantly reduced in rings with endothelium taken fro...