Antihypertensive effects of a dietary unsaturated FA mixture in spontaneously hypertensive rats

Abstract

The aim of the present study was to investigate whether a mixture of dietary n-6 and n-3 PUFA could lower blood pressure in spontaneously hypertensive rats (SHR) of different ages. In addition, we studied how such a treatment could normalize the FA composition of plasma TAG and cholesterol esters (CE), and of red blood cell (RBC) total lipids. SHR (ages 4, 19, and 50 wk) were fed a normal diet (control groups) or a semisynthetic diet containing a mixture of gamma-linolenic acid (GLA), EPA, and DHA (experimental groups). Systolic blood pressure was measured at regular intervals. After 11 wk of consuming this diet, plasma TAG and CE were separated by TLC and analyzed for their FA composition. Total FA composition of RBC was also determined. The degree to which blood pressure was elevated was reduced in SHR after 11 wk of diet. The largest decrease was obtained with the oldest animals. In RBC, EPA and DHA contents increased. In plasma TAG and CE, EPA, DHA, and GLA increased whereas arachidonic acid decreased. The n-6 and n-3 unsaturated FA mix slowed the development of hypertension in young SHR and decreased blood pressure in adult and aged SHR. In addition, the present treatment altered the n-3 and n-6 PUFA content of SHR lipids to that seen in normotensive rats.

Dietary fish oil improves endothelial function and lowers blood pressure via suppression of sphingolipid-mediated contractions in spontaneously hypertensive rats

“…A diet rich in n-3 LCPUFA lowers the membrane arachidonic acid content and consequently the production of arachidonic acid-derived eicosanoids [43,44]. Indeed, in SHR erythrocyte membranes, we demonstrated arachidonic acid as one of the predominant fatty acids, which was reduced by the fish oil diet, as demonstrated by others [33]. This substitution likely affects vascular substrate availability for COX to generate the contractile factor thromboxane in our experiments and it is feasible that a similar mechanism may improve endothelial cell function in the human situation as well.…”

Distinct regulation of stearoyl-CoA desaturase 1 gene expression by cis and trans C18:1 fatty acids in human aortic smooth muscle cells

“…Lipid extraction was performed by a Folch modified method (Bellenger-Germain et al 2002) and followed by saponification/methylation. Methyl esters were analysed by gas chromatography (GC) on Clarus 500 (Perkin-Elmer) chromatograph equipped with on-column injector and FID detector.…”

The Role of Dietary Fats in Hypertension, Obesity and Insulin Resistance: A Comparative Study of Animals and Humans in Fetal and Adult Life

“…After 6 weeks of feeding DHA to SHR, these animals had SBP measurements averaging 34 mmHg less than the control animals. Antihypertensive properties of unsaturated fats have also been found in SHR at various ages [14]. A diet enriched with GLA, EPA, and DHA, produced a decrease in the development of hypertension in both younger and adult SHRs.…”

“…The basis for the hypotensive properties of the n-3 fatty acids, specifically EPA and DHA has been provided by earlier work [7][8][9][10], while more recent literature has certainly confirmed the beneficial effects of n-3 fatty acids on hypertension in animal models [11][12][13][14][15][16][17]. Diets rich in gammalinoleic acid (GLA), EPA and DHA were shown to significantly decrease blood pressure by -20 mmHg in SHR, while no effect was seen on the normotensive Wistar Kyoto rats (WKY) on the PUFA diet [13].…”