promega and Hypertension

Topics: Aged; Blood Pressure; Docosahexaenoic Acids; Double-Blind Method; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Female; Fish Oils; Humans; Hypertension; Male; Middle Aged

We investigated the effects of dietary MaxEPA (a major source of eicosapentaenoic acid in fish oil) supplementation on blood pressure (BP) responses and heart rate (HR) of Dahl salt-sensitive (SS) rats fed low (0.4% NaCl) and high (8.0% NaCl) sodium diets. During a four week treatment period, BP remained normotensive in rats on low salt diet but was significantly elevated in those on high salt diet, causing 50% mortality. MaxEPA diminished the BP elevation and prevented the high salt-induced mortality. HR was not affected by either salt diet alone but was reduced in the presence of MaxEPA. At the end of the treatment period, the distribution of [3H]nitrobenzylthioinosine ([3H]NBMPR) binding, a putative marker of adenosine transport and metabolism, was estimated in selected rat tissues in order to evaluate the role of the purinergic system in the BP lowering effect of MaxEPA. Maximal [3H]NBMPR binding capacity (Bmax) in the kidney and platelets were 39% and 82% lower, respectively, in rats on high salt diet than in those on low salt diet. MaxEPA significantly blunted the decrease in Bmax in the kidney but not in platelets and increased Bmax in heart (48%) of low salt group. There were no changes in dissociation constants (Kd). The results suggest that MaxEPA can attenuate salt-induced hypertension, reduce salt-induced mortality and protect the integrity of kidney NBMPR binding sites in salt-induced hypertension.

Topics: Affinity Labels; Animals; Binding Sites; Blood Platelets; Blood Pressure; Body Weight; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Heart Rate; Hypertension; Kidney; Male; Rats; Rats, Sprague-Dawley; Sodium Chloride, Dietary; Thioinosine

The effect of dietary fish oils on development of hypertension and vascular response in vitro were studied in rats and a primate. Dietary fish oils (MaxEPA and an n-3 ethyl ester concentrate of higher EPA and DHA content) were administered to spontaneously hypertensive (SHR), stroke-prone spontaneously hypertensive (SHR-SP) and a backcross of SHR and Wistar Kyoto (SHR/WKY) rats from 4-16 weeks of age. Blood pressure was monitored during the feeding period and vascular responses measured in the aorta and mesenteric vascular bed in vitro. Depending on the strain of rat used and the composition of the fish oil the attenuation in blood pressure was 10-26 mmHg. Fish oils attenuated the response mediated by sympathetic nerve stimulation or intralumenal norepinephrine in the perfused mesenteric vascular bed preparation from the SHR. This attenuation was more pronounced for fish oils enriched with eicosapentaenoic acid and docosahexaenoic acid and was more prominent in the SHR and SHR/WKY backcross than it was in the SHR-SP. Prostanoid synthesis or nitric oxide modulation of alpha-adrenoceptor responses were shown not to be involved in the attenuation of vascular responses produced by fish oil. The maximum contraction of aortic ring preparations in response to norepinephrine (NE) was significantly smaller in SHR than WKY rats fed olive oil and for SHR rats maintained on fish oils the contraction was close to WKY olive oil values. Evidence was obtained also for a modulation of vasoconstrictor responses by dietary fish oils in the perfused mesenteric bed of the marmoset monkey.

Topics: Animals; Blood Pressure; Callithrix; Cerebrovascular Disorders; Crosses, Genetic; Dietary Fats, Unsaturated; Disease Susceptibility; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Fish Oils; Hypertension; Male; Nitric Oxide; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Species Specificity; Vasoconstriction

Topics: Aspirin; Blood Pressure; Creatinine; Diabetic Nephropathies; Dipyridamole; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Female; Fish Oils; Glomerular Filtration Rate; Hemostasis; Humans; Hypertension; Kidney Failure, Chronic; Male; Platelet Aggregation Inhibitors; Proteinuria

Topics: Animals; Blood Pressure; Docosahexaenoic Acids; Drug Combinations; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Fish Oils; Hypertension; Male; Prostaglandins; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Sodium Chloride