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Vasorelaxant properties of n-3 polyunsaturated fatty acids in aortas from spontaneously hypertensive and normotensive rats.
J Cardiovasc Risk. 1994 Jun; 1(1):75-80.JC

Abstract

BACKGROUND

Dietary consumption of fish, rich in n-3 polyunsaturated fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), has been shown to reduce blood pressure in both animal studies and clinical trials. Although the antihypertensive mechanisms are not known, the blood-pressure-lowering effect of n-3 polyunsaturated fatty acids may be partially attributed to their vasorelaxant properties.

METHODS

Aortic rings with and without endothelium, from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR), 16-17 weeks old, were suspended in tissue baths and isometric tension was measured. Concentration-response curves were generated for DHA and EPA (1-100 mu mol/l) in norepinephrine-contracted rings. Blood pressure was measured using the tail-cuff method and aortic media thickness was determined.

RESULTS

Blood pressure was significantly increased in SHR (n=10; 194 +/- 4.4 mmHg) compared with WKY (n=10; 124 +/- 1.2 mmHg, P < or = 0.0001). DHA (1-100 mu mol/l) relaxed aortic rings f rom WKY (-3.3 +/- 0.7 to -13 +/- 2.3%, P < or = 0.001) and from SHR (-6.5 +/- 1.8 to -22.9 +/- 4%, P < or = 0.01) in a concentration-dependent manner. EPA (1-100 mu mol/l) evoked greater relaxation in SHR (-10.1 +/- 2.0 to -33 +/- 3.9%, P < 0.01) than in WKY (-2.9 +/- 1.1 to -18.3 +/- 2.1%, P < 0.01) aortic rings. The relaxant effect of DHA in both WKY and SHR and of EPA in WKY were not dependent on an intact endothelium. However, EPA (1-10 mu mol/l) induced greater responses in intact SHR rings (-10.1 +/- 2.0 to -14.5 +/- 3.1%) than in de-endothelialized SHR rings (0 to -2.1 +/- 1.7%, P = 0.001).

CONCLUSION

The direct relaxant effects of n-3 fatty acids as seen in WKY and SHR may contribute, in part, toward the blood-pressure-lowering effect of dietary fish and fish-oil supplementation.

Authors+Show Affiliations

University of California, Department of Physiological Nursing, San Francisco, 94143-0610, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

7614421

Citation

Engler, M B., et al. "Vasorelaxant Properties of N-3 Polyunsaturated Fatty Acids in Aortas From Spontaneously Hypertensive and Normotensive Rats." Journal of Cardiovascular Risk, vol. 1, no. 1, 1994, pp. 75-80.
Engler MB, Engler MM, Ursell PC. Vasorelaxant properties of n-3 polyunsaturated fatty acids in aortas from spontaneously hypertensive and normotensive rats. J Cardiovasc Risk. 1994;1(1):75-80.
Engler, M. B., Engler, M. M., & Ursell, P. C. (1994). Vasorelaxant properties of n-3 polyunsaturated fatty acids in aortas from spontaneously hypertensive and normotensive rats. Journal of Cardiovascular Risk, 1(1), 75-80.
Engler MB, Engler MM, Ursell PC. Vasorelaxant Properties of N-3 Polyunsaturated Fatty Acids in Aortas From Spontaneously Hypertensive and Normotensive Rats. J Cardiovasc Risk. 1994;1(1):75-80. PubMed PMID: 7614421.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Vasorelaxant properties of n-3 polyunsaturated fatty acids in aortas from spontaneously hypertensive and normotensive rats. AU - Engler,M B, AU - Engler,M M, AU - Ursell,P C, PY - 1994/6/1/pubmed PY - 1994/6/1/medline PY - 1994/6/1/entrez SP - 75 EP - 80 JF - Journal of cardiovascular risk JO - J Cardiovasc Risk VL - 1 IS - 1 N2 - BACKGROUND: Dietary consumption of fish, rich in n-3 polyunsaturated fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), has been shown to reduce blood pressure in both animal studies and clinical trials. Although the antihypertensive mechanisms are not known, the blood-pressure-lowering effect of n-3 polyunsaturated fatty acids may be partially attributed to their vasorelaxant properties. METHODS: Aortic rings with and without endothelium, from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR), 16-17 weeks old, were suspended in tissue baths and isometric tension was measured. Concentration-response curves were generated for DHA and EPA (1-100 mu mol/l) in norepinephrine-contracted rings. Blood pressure was measured using the tail-cuff method and aortic media thickness was determined. RESULTS: Blood pressure was significantly increased in SHR (n=10; 194 +/- 4.4 mmHg) compared with WKY (n=10; 124 +/- 1.2 mmHg, P < or = 0.0001). DHA (1-100 mu mol/l) relaxed aortic rings f rom WKY (-3.3 +/- 0.7 to -13 +/- 2.3%, P < or = 0.001) and from SHR (-6.5 +/- 1.8 to -22.9 +/- 4%, P < or = 0.01) in a concentration-dependent manner. EPA (1-100 mu mol/l) evoked greater relaxation in SHR (-10.1 +/- 2.0 to -33 +/- 3.9%, P < 0.01) than in WKY (-2.9 +/- 1.1 to -18.3 +/- 2.1%, P < 0.01) aortic rings. The relaxant effect of DHA in both WKY and SHR and of EPA in WKY were not dependent on an intact endothelium. However, EPA (1-10 mu mol/l) induced greater responses in intact SHR rings (-10.1 +/- 2.0 to -14.5 +/- 3.1%) than in de-endothelialized SHR rings (0 to -2.1 +/- 1.7%, P = 0.001). CONCLUSION: The direct relaxant effects of n-3 fatty acids as seen in WKY and SHR may contribute, in part, toward the blood-pressure-lowering effect of dietary fish and fish-oil supplementation. SN - 1350-6277 UR - https://www.unboundmedicine.com/medline/citation/7614421/Vasorelaxant_properties_of_n_3_polyunsaturated_fatty_acids_in_aortas_from_spontaneously_hypertensive_and_normotensive_rats_ L2 - http://ovidsp.ovid.com/ovidweb.cgi?T=JS&amp;PAGE=linkout&amp;SEARCH=7614421.ui DB - PRIME DP - Unbound Medicine ER -