Abstract
1. To investigate possible mechanisms of increased systolic blood pressure after 1 weeks treatment with dexamethasone and its amelioration by fish oil feeding, we have examined the reactivity of aortic rings and perfused mesenteric resistance vessels. 2. Thirty six Sprague-Dawley rats were initially divided into two groups and fed a semisynthetic diet containing either (10% by weight) hydrogenated coconut oil and safflower oil mixture (HCO/S) (24 rats) or fish oil (12 rats) for 5 weeks. From the end of the fourth week, dexamethasone (1.25 mg ml-1) in drinking water, was given to half the rats on hydrogenated coconut oil (HCO/S+Dex) and to the fish oil-fed group (fish oil+Dex). 3. One week of dexamethasone treatment raised systolic blood pressure in the HCO/S+Dex rats but not in the fish oil+Dex group. 4. Endothelium-dependent relaxation to acetylcholine (ACh) was decreased in aortic rings taken from HCO/S+Dex rats compared to rats on HCO/S alone. Relaxant responses to ACh of aortic rings from rats given fish oil+Dex were intermediate between the three groups. Aortic endothelium-independent responses to sodium nitroprusside (SNP) were unchanged between the groups, while aortic contractile responses to noradrenaline were similar in all the groups. 5. In the perfused mesenteric resistance artery, sensitivity to noradrenaline was decreased in rats given fish oil and dexamethasone compared to the other two groups. There were no differences in resistance vessel relaxation to ACh or SNP between groups. 6. Serum corticosterone levels, used as a marker of dexamethasone absorption, were substantially suppressed in dexamethasone-treated rats but levels were higher in rats on fish oil than on HCO/S diets.(ABSTRACT TRUNCATED AT 250 WORDS)
Full text
PDF







Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Boulanger C., Schini V. B., Hendrickson H., Vanhoutte P. M. Chronic exposure of cultured endothelial cells to eicosapentaenoic acid potentiates the release of endothelium-derived relaxing factor(s). Br J Pharmacol. 1990 Jan;99(1):176–180. doi: 10.1111/j.1476-5381.1990.tb14673.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bullock G. R., Taylor S. G., Weston A. H. Influence of the vascular endothelium on agonist-induced contractions and relaxations in rat aorta. Br J Pharmacol. 1986 Dec;89(4):819–830. doi: 10.1111/j.1476-5381.1986.tb11187.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chu Z. M., Yin K., Beilin L. J. Fish oil feeding selectively attenuates contractile responses to noradrenaline and electrical stimulation in the perfused mesenteric resistance vessels of spontaneously hypertensive rats. Clin Exp Pharmacol Physiol. 1992 Mar;19(3):177–181. doi: 10.1111/j.1440-1681.1992.tb00435.x. [DOI] [PubMed] [Google Scholar]
- Cocks T. M., Angus J. A. Endothelium-dependent relaxation of coronary arteries by noradrenaline and serotonin. Nature. 1983 Oct 13;305(5935):627–630. doi: 10.1038/305627a0. [DOI] [PubMed] [Google Scholar]
- Codde J. P., Beilin L. J., Croft K. D. Dissociation of effects of dietary fatty acids on blood pressure and prostanoid metabolism in Goldblatt hypertensive rats. J Hypertens. 1984 Feb;2(1):65–71. doi: 10.1097/00004872-198402000-00012. [DOI] [PubMed] [Google Scholar]
- Codde J. P., Beilin L. J. Dietary fish oil prevents dexamethasone induced hypertension in the rat. Clin Sci (Lond) 1985 Dec;69(6):691–699. doi: 10.1042/cs0690691. [DOI] [PubMed] [Google Scholar]
- Erman A., Hassid A., Baer P. G., Nasjletti A. Treatment with dexamethasone increases glomerular prostaglandin synthesis in rats. J Pharmacol Exp Ther. 1986 Oct;239(1):296–301. [PubMed] [Google Scholar]
- Furchgott R. F., Jothianandan D., Cherry P. D. Endothelium-dependent responses: the last three years. Bibl Cardiol. 1984;(38):1–15. [PubMed] [Google Scholar]
- Handa M., Kondo K., Suzuki H., Saruta T. Dexamethasone hypertension in rats: role of prostaglandins and pressor sensitivity to norepinephrine. Hypertension. 1984 Mar-Apr;6(2 Pt 1):236–241. [PubMed] [Google Scholar]
- Iijima F., Malik K. U. Mesenteric vascular reactivity in dexamethasone-treated hypertensive rats. Hypertension. 1985 Sep-Oct;7(5):783–790. doi: 10.1161/01.hyp.7.5.783. [DOI] [PubMed] [Google Scholar]
- Kalsner S. Mechanism of hydrocortisone potentiation of responses to epinephrine and norepinephrine in rabbit aorta. Circ Res. 1969 Mar;24(3):383–395. doi: 10.1161/01.res.24.3.383. [DOI] [PubMed] [Google Scholar]
- Kato T., Iwama Y., Okumura K., Hashimoto H., Ito T., Satake T. Prostaglandin H2 may be the endothelium-derived contracting factor released by acetylcholine in the aorta of the rat. Hypertension. 1990 May;15(5):475–481. doi: 10.1161/01.hyp.15.5.475. [DOI] [PubMed] [Google Scholar]
- Koga T., Takata Y., Kobayashi K., Takishita S., Yamashita Y., Fujishima M. Age and hypertension promote endothelium-dependent contractions to acetylcholine in the aorta of the rat. Hypertension. 1989 Nov;14(5):542–548. doi: 10.1161/01.hyp.14.5.542. [DOI] [PubMed] [Google Scholar]
- Konishi M., Su C. Role of endothelium in dilator responses of spontaneously hypertensive rat arteries. Hypertension. 1983 Nov-Dec;5(6):881–886. doi: 10.1161/01.hyp.5.6.881. [DOI] [PubMed] [Google Scholar]
- Lüscher T. F., Raij L., Vanhoutte P. M. Endothelium-dependent vascular responses in normotensive and hypertensive Dahl rats. Hypertension. 1987 Feb;9(2):157–163. doi: 10.1161/01.hyp.9.2.157. [DOI] [PubMed] [Google Scholar]
- Lüscher T. F., Vanhoutte P. M. Endothelium-dependent contractions to acetylcholine in the aorta of the spontaneously hypertensive rat. Hypertension. 1986 Apr;8(4):344–348. doi: 10.1161/01.hyp.8.4.344. [DOI] [PubMed] [Google Scholar]
- Matthews J. N., Altman D. G., Campbell M. J., Royston P. Analysis of serial measurements in medical research. BMJ. 1990 Jan 27;300(6719):230–235. doi: 10.1136/bmj.300.6719.230. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nasjletti A., Erman A., Cagen L. M., Baer P. G. Plasma concentrations, renal excretion, and tissue release of prostaglandins in the rat with dexamethasone-induced hypertension. Endocrinology. 1984 Mar;114(3):1033–1040. doi: 10.1210/endo-114-3-1033. [DOI] [PubMed] [Google Scholar]
- Palmer R. M., Ferrige A. G., Moncada S. Nitric oxide release accounts for the biological activity of endothelium-derived relaxing factor. Nature. 1987 Jun 11;327(6122):524–526. doi: 10.1038/327524a0. [DOI] [PubMed] [Google Scholar]
- Rees D. D., Cellek S., Palmer R. M., Moncada S. Dexamethasone prevents the induction by endotoxin of a nitric oxide synthase and the associated effects on vascular tone: an insight into endotoxin shock. Biochem Biophys Res Commun. 1990 Dec 14;173(2):541–547. doi: 10.1016/s0006-291x(05)80068-3. [DOI] [PubMed] [Google Scholar]
- Russo D., Fraser R., Kenyon C. J. Dexamethasone therapy selectively increases the sensitivity to noradrenaline of the rat mesenteric circulation. J Hypertens Suppl. 1989 Dec;7(6):S126–S127. doi: 10.1097/00004872-198900076-00059. [DOI] [PubMed] [Google Scholar]
- Schoene N. W., Fiore D. Effect of a diet containing fish oil on blood pressure in spontaneously hypertensive rats. Prog Lipid Res. 1981;20:569–570. doi: 10.1016/0163-7827(81)90102-8. [DOI] [PubMed] [Google Scholar]
- Sessa W. C., Halushka P. V., Okwu A., Nasjletti A. Characterization of the vascular thromboxane A2/prostaglandin endoperoxide receptor in rabbit aorta. Regulation by dexamethasone. Circ Res. 1990 Dec;67(6):1562–1569. doi: 10.1161/01.res.67.6.1562. [DOI] [PubMed] [Google Scholar]
- Sessa W. C., Nasjletti A. Dexamethasone selectively attenuates prostanoid-induced vasoconstrictor responses in vitro. Circ Res. 1990 Feb;66(2):383–388. doi: 10.1161/01.res.66.2.383. [DOI] [PubMed] [Google Scholar]
- Shimokawa H., Aarhus L. L., Vanhoutte P. M. Dietary omega 3 polyunsaturated fatty acids augment endothelium-dependent relaxation to bradykinin in coronary microvessels of the pig. Br J Pharmacol. 1988 Dec;95(4):1191–1196. doi: 10.1111/j.1476-5381.1988.tb11755.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shimokawa H., Lam J. Y., Chesebro J. H., Bowie E. J., Vanhoutte P. M. Effects of dietary supplementation with cod-liver oil on endothelium-dependent responses in porcine coronary arteries. Circulation. 1987 Oct;76(4):898–905. doi: 10.1161/01.cir.76.4.898. [DOI] [PubMed] [Google Scholar]
- Shimokawa H., Vanhoutte P. M. Dietary omega 3 fatty acids and endothelium-dependent relaxations in porcine coronary arteries. Am J Physiol. 1989 Apr;256(4 Pt 2):H968–H973. doi: 10.1152/ajpheart.1989.256.4.H968. [DOI] [PubMed] [Google Scholar]
- Tonolo G., Fraser R., Connell J. M., Kenyon C. J. Chronic low-dose infusions of dexamethasone in rats: effects on blood pressure, body weight and plasma atrial natriuretic peptide. J Hypertens. 1988 Jan;6(1):25–31. [PubMed] [Google Scholar]
- Van de Voorde J., Leusen I. Endothelium-dependent and independent relaxation of aortic rings from hypertensive rats. Am J Physiol. 1986 May;250(5 Pt 2):H711–H717. doi: 10.1152/ajpheart.1986.250.5.H711. [DOI] [PubMed] [Google Scholar]
- Waeber B., Gavras H., Bresnahan M. R., Gavras I., Brunner H. R. Role of vasoconstrictor systems in experimental glucocorticoid-hypertension in rats. Clin Sci (Lond) 1983 Sep;65(3):255–261. doi: 10.1042/cs0650255. [DOI] [PubMed] [Google Scholar]
- Watt P. A., Thurston H. Endothelium-dependent relaxation in resistance vessels from the spontaneously hypertensive rats. J Hypertens. 1989 Aug;7(8):661–666. doi: 10.1097/00004872-198908000-00010. [DOI] [PubMed] [Google Scholar]
- Yin K., Chu Z. M., Beilin L. J. Blood pressure and vascular reactivity changes in spontaneously hypertensive rats fed fish oil. Br J Pharmacol. 1991 Apr;102(4):991–997. doi: 10.1111/j.1476-5381.1991.tb12289.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yin K., Chu Z. M., Beilin L. J. Effect of fish oil feeding on blood pressure and vascular reactivity in spontaneously hypertensive rats. Clin Exp Pharmacol Physiol. 1990 Mar;17(3):235–239. doi: 10.1111/j.1440-1681.1990.tb01313.x. [DOI] [PubMed] [Google Scholar]
