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EFFECT OF FISH OIL FEEDING ON BLOOD PRESSURE AND VASCULAR REACTIVITY IN SPONTANEOUSLY HYPERTENSIVE RATS
Author(s) -
Yin K.,
Chu Z. M.,
Beilin L. J.
Publication year - 1990
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1990.tb01313.x
Subject(s) - fish oil , blood pressure , medicine , aorta , endocrinology , thromboxane , thromboxane b2 , chemistry , thromboxane a2 , acetylcholine , fish <actinopterygii> , biology , platelet , fishery
SUMMARY 1. To examine possible antihypertensive mechanisms of fish oil feeding, we have studied vascular reactivity of aortic rings and blood pressure of spontaneously hypertensive rats (SHR). 2. SHR were fed a synthetic diet supplemented with either (10% by weight) ‘Max EPA’ fish oil or hydrogenated coconut oil (saturated fat) for 4 weeks. 3. Mean systolic blood pressure of fish oil fed rats was 9 mmHg lower than saturated fat fed controls. 4. Aortic rings of control SHR had a biphasic response to acetylcholine (ACh), relaxing at lower concentrations but contracting at concentrations higher than 3X10 ‐7 mol/L. No such contractions were seen in tissues of fish oil fed rats. The contractions were abolished by indomethacin, suggesting that they were caused by a cyclo‐oxygenase product. 5. Tissue analysis showed that both aortic and serum generation of thromboxane B 2 (TxB 2 ) was approximately three times less in fish oil fed rats than in control tissues. 6. These results indicate that the lowering of blood pressure in fish oil fed SHR could in part be due to decrease in production of thromboxane (TxA 2 ), a potent vasoconstrictor, hence influencing vascular tone and compliance of the aorta.