Dietary omega-3 fatty acids and endothelium-dependent responses in porcine cerebral arteries.
OBJECTIVE
We sought to determine the effect of dietary omega-3 polyunsaturated fatty acids on cerebrovascular endothelium-dependent responses in studies performed on isolated porcine basilar arteries.


METHODS
Male Yorkshire pigs (6-8 weeks old) were kept for 4 weeks on a standard diet (control group, n = 12) or on chow supplemented with polyunsaturated fatty acids (eicosapentaenoic acid, 3.5 g/day, or docosahexaenoic acid, 1.5 g/day; treated group, n = 12). Isometric tension recording of the basilar artery was carried out and responses were compared between the two groups.


RESULTS
The regimen resulted in a decrease in the plasma arachidonic acid level and an increase in eicosapentaenoic acid. Endothelium-dependent relaxations induced by bradykinin and adenosine diphosphate were augmented in the basilar arteries of the treated group. Incubation with indomethacin (10(-5) M) prevented the augmentation of the relaxations induced by bradykinin, but not those caused by adenosine diphosphate. The indomethacin-sensitive, endothelium-dependent contractions to arachidonic acid remained comparable in the two groups, indicating that the activity of cyclooxygenase was not affected by the diet.


CONCLUSIONS
Dietary supplementation with omega-3 polyunsaturated fatty acids enhances endothelium-dependent relaxations in the basilar artery by two mechanisms: 1) replacement of endogenous arachidonic acid and suppression of the concomitant release of vasoconstrictor prostaglandins from the endothelium, and 2) enhancement of the release of endothelium-derived relaxing factor.
Kim
P
P
Department of Physiology and Biophysics Mayo Clinic, Rochester, Minn.
Shimokawa
H
H
Vanhoutte
P M
PM
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001488:Basilar Artery / Q000187:drug effects* / Q000502:physiology; D001920:Bradykinin / Q000494:pharmacology; D004041:Dietary Fats / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D011189:Potassium Chloride / Q000494:pharmacology; D013552:Swine; D014661:Vasoconstriction
D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D000244:Adenosine Diphosphate; D011189:Potassium Chloride; D001920:Bradykinin; D007213:Indomethacin