scholarly journals Role of oxidative stress in elevated blood pressure induced by high free fatty acids

2009 ◽  
Vol 32 (2) ◽  
pp. 152-158 ◽  
Author(s):  
Hui Wang ◽  
Hongliang Li ◽  
Zhiqiang Hou ◽  
Lin Pan ◽  
Xiaoxia Shen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Elevated Blood Pressure ◽  
Elevated Blood

Bezafibrate, an anti-hypertriglyceridemic drug, attenuates vascular hyperresponsiveness and elevated blood pressure in fructose-induced hypertensive rats

1999 ◽  
Vol 77 (10) ◽  
pp. 755-762 ◽  
Author(s):  
Xiaochen Si ◽  
R Clinton Webb ◽  
Joyce M Richey
Keyword(s):  
Blood Pressure ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Lipid Profile ◽  
Vascular Reactivity ◽  
Bay K 8644 ◽  
Elevated Blood Pressure ◽  
Male Rats ◽  
Elevated Blood ◽  
Lipid Abnormalities

A high fructose diet induces hypertension, hyperinsulinemia - insulin resistance, and hypertriglyceridemia (syndrome X). In this study, we investigated the role of an abnormal lipid profile in mediating fructose-induced hypertension. We hypothesized that bezafibrate, a lipid-lowering drug, would reduce elevated blood pressure and inhibit increased vascular reactivity in fructose-fed rats. Male rats were placed on four different diets: group 1 was fed standard chow (n = 6); group 2 was fed 60% fructose (n = 5); group 3 was fed fructose plus bezafibrate (30 mg·kg-1·day-1; drinking water; n = 5); and group 4 was fed standard chow plus bezafibrate (n = 6). In addition, the direct effects of very low density lipoprotein (VLDL) on vascular reactivity were examined. Bezafibrate treatment lowered blood pressure, free fatty acids, and triglycerides in the fructose-fed group, suggesting that lipid abnormalities play a role in the elevation of blood pressure in the fructose-induced hypertensive rat. Aortae from fructose-fed rats were hyperresponsive to the calcium channel agonist Bay K 8644, which was normalized with bezafibrate treatment. Incubation of aortae in a VLDL medium resulted in increased responsiveness to Bay K 8644, lending further support to lipid abnormalities altering vascular reactivity. An altered lipid profile evidenced by elevated triglycerides and free fatty acids is causally related to the development of high blood pressure and increased vascular reactivity in the fructose-induced hypertensive rat.Key words: Sprague-Dawley rats, hypertriglyceridemia, free fatty acids, vascular reactivity, aortae.

Changes in calcium metabolic indices during long-term treatment of patients with essential hypertension

1988 ◽  
Vol 75 (5) ◽  
pp. 543-549 ◽  
Author(s):  
Andreas Hvarfner ◽  
Reinhold Bergström ◽  
Hans Lithell ◽  
Claes Mörlin ◽  
Leif Wide ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Fatty Acids ◽  
Essential Hypertension ◽  
Parathyroid Hormone ◽  
Free Fatty Acids ◽  
Calcium Metabolism ◽  
Elevated Blood Pressure ◽  
Ionized Calcium ◽  
Elevated Blood ◽  
Metabolic Indices

1. Disturbances of calcium metabolism, mimicking mild, compensated secondary hyperparathyroidism, accompany essential hypertension, but it is not known whether these alterations are primary or only secondary to the elevated blood pressure. 2. Indices of systemic calcium metabolism were followed prospectively during 6 months' treatment with either propranolol, bendroflumethiazide or verapamil in 35 patients with essential hypertension. Multivariate statistical methods were employed to study the effects of blood pressure reduction upon the metabolic indices with adjustment for the effects of the different antihypertensive agents. 3. Propranolol treatment increased the plasma ionized calcium and serum phosphate concentrations, and reduced the serum levels of parathyroid hormone, free fatty acids and glycerol. Neither the total nor the total albumin-modified serum calcium concentration was significantly affected. Thus, presumably the decrease in free fatty acids reduced the calcium complex and the calcium binding to albumin, and consequently increased the plasma ionized calcium, thereby suppressing the secretion of parathyroid hormone. 4. Bendroflumethiazide caused a reduction of the fasting renal calcium excretion to half the pretreatment level, but produced no other significant changes in the various indices of calcium metabolism. 5. During verapamil treatment, the fasting renal excretion of calcium and magnesium increased, whereas the free fatty acids and glycerol concentrations in serum were reduced. These two changes presumably balanced each other, as the plasma ionized calcium and serum parathyroid hormone concentrations were not significantly altered. 6. There were no consistent relationships between the decrease in blood pressure and the changes in the metabolic indices, either in the total sample or within any subgroup. These findings indicate that disturbances of calcium metabolism in essential hypertension are primary to, and not induced by, the elevated blood pressure per se.

ROLE OF THE THYROID GLAND IN DEVELOPMENT AND MAINTENANCE OF RENAL HYPERTENSION IN RATS

1960 ◽  
Vol XXXIV (III) ◽  
pp. 411-429 ◽  
Author(s):  
Melvin J. Fregly ◽  
Kenneth M. Cook
Keyword(s):  
Blood Pressure ◽  
Rate Increase ◽  
Renal Hypertension ◽  
The Other ◽  
Elevated Blood Pressure ◽  
Unit Weight ◽  
Elevated Blood ◽  
Inhibition Of Growth ◽  
Testicular Size

ABSTRACT The anti-thyroid drugs, thiouracil, propylthiouracil, and methimazole, prevented both development of elevated blood pressure and cardiac hypertrophy usually accompanying kidney encapsulation with latex envelopes. These drugs also reduced elevated blood pressure of rats with hypertension of 13 to 40 weeks' duration prior to drug administration. Addition of desiccated thyroid powder to diet containing an anti-thyroid drug overcame the anti-hypertensive effect of the latter. Withdrawal of thyroid powder only was followed by return of blood pressure to previous low level within 3 weeks. The results suggest that the anti-hypertensive effect of these drugs is related directly to the hypothyroidism produced rather than to extrathyroidal effects of the drugs. Comparison of potencies of the 3 drugs in terms of anti-hypertensive effect, inhibition of growth rate, increase in testicular size, and increase in thyroid size suggests that propylthiouracil and methimazole are equally potent per unit weight of drug. Thiouracil has approximately half the potency of the other two.

scholarly journals Role of community health volunteers in identifying people with elevated blood pressure for diagnosis and monitoring of hypertension in Malawi: a qualitative study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elvis Safary ◽  
Micrina Mwandeti ◽  
Beatrice Matanje ◽  
Claudia Beiersmann ◽  
Caroline Mtaita ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Community Health ◽  
Communicable Diseases ◽  
Health Facilities ◽  
Elevated Blood Pressure ◽  
Elevated Blood ◽  
Structured Interviews ◽  
Community Health Volunteers ◽  
Provision Of Services

Abstract Background In recent years, there has been greater recognition of the important role of community health volunteers in many countries and their important role informs many health programs. This include health education, provision of services such as screening, monitoring and referral to health facilities. Their roles are better understood in the areas of communicable diseases like HIV infection, Tuberculosis and Malaria however little is known about their role in non-communicable diseases. This study seeks to explore perception of CHVs’ functions, tasks, and their fulfilment in identifying people with elevated blood pressure for diagnosis and monitoring of hypertension in Lilongwe, Malawi. Methods This was a qualitative naturalistic research design utilizing observation and semi-structured interviews with community health volunteers working in Lilongwe, Malawi. Interviews were carried out with the researcher. Participants were recruited from the ZaMaC project. An interview guide was developed with a category-guided deductive approach. The interviews were recorded through note taking. Data analysis was performed using content analysis approach. Results Community health volunteers have multiple roles in prevention and monitoring of hypertension. They act as health educators and provide lifestyle counselling. They screened for hypertension and monitored blood pressure and assisted community members to navigate the health system such as linkage to health facilities. These roles were shaped in response to community needs. Conclusion This study indicates the complexities of the roles of community health volunteer in identifying people with elevated BP for diagnosis and monitoring of hypertension. Understanding community health volunteers’ roles provides insight into their required competencies in provision of their daily activities as well as required training to fill in their knowledge gaps.

scholarly journals Nitric oxide synthase-mediated blood pressure regulation in obese melanocortin-4 receptor-deficient pregnant rats

2016 ◽  
Vol 311 (5) ◽  
pp. R851-R857 ◽  
Author(s):  
Frank T. Spradley ◽  
Jennifer M. Sasser ◽  
Jacqueline B. Musall ◽  
Jennifer C. Sullivan ◽  
Joey P. Granger
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Mesenteric Arteries ◽  
Elevated Blood Pressure ◽  
Pressure Regulation ◽  
Elevated Blood ◽  
Pregnant Rats ◽  
Melanocortin 4 Receptor ◽  
Regulation Of Blood Pressure

Although obesity increases the risk for hypertension in pregnancy, the mechanisms responsible are unknown. Increased nitric oxide (NO) production results in vasodilation and reduced blood pressure during normal pregnancy in lean rats; however, the role of NO is less clear during obese pregnancies. We examined the impact of obesity on NO synthase (NOS)-mediated regulation of blood pressure during pregnancy by testing the hypothesis that NOS activity, expression, and regulation of vascular tone and blood pressure are reduced in obese pregnant rats. At gestational day 19, melanocortin-4 receptor (MC4R)-deficient obese rats (MC4R) had greater body weight and fat mass with elevated blood pressure and circulating sFlt-1 levels compared with MC4R pregnant rats. MC4R pregnant rats also had less circulating cGMP levels and reduced total NOS enzymatic activity and expression in mesenteric arteries. Despite decreased biochemical measures of NO/NOS in MC4R rats, NOS inhibition enhanced vasoconstriction only in mesenteric arteries from MC4R rats, suggesting greater NOS-mediated tone. To examine the role of NOS on blood pressure regulation in obese pregnant rats, MC4R and MC4R pregnant rats were administered the nonselective NOS inhibitor NG-nitro-l-arginine methyl ester (l-NAME, 100 mg/l) from gestational day 14 to 19 in drinking water. The degree by which l-NAME raised blood pressure was similar between obese and lean pregnant rats. Although MC4R obese pregnant rats had elevated blood pressure associated with reduced total NOS activity and expression, they had enhanced NOS-mediated attenuation of vasoconstriction, with no evidence of alterations in NOS-mediated regulation of blood pressure.

Abstract P040: Role of 20-HETE in Elevated Blood Pressure in Hyperandrogenemic Female Rats, a Model of Polycystic Ovarian Syndrome

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Chetan N Patil ◽  
Carolina Dalmasso ◽  
Rodrigo O Maranon ◽  
Huimin Zhang ◽  
Richard J Roman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Polycystic Ovary ◽  
Premenopausal Women ◽  
Female Rats ◽  
Elevated Blood Pressure ◽  
Female Rat ◽  
Elevated Blood ◽  
Reproductive Disorder ◽  
Consomic Strain

Polycystic ovary syndrome (PCOS) is the most common reproductive disorder in premenopausal women, is characterized by hyperandrogenemia, metabolic syndrome and inflammation. They also exhibit elevated blood pressure (BP) but may not be treated since they do not meet the criteria for hypertension (BP>130/90 mm Hg). We have characterized a female rat model of hyperandrogenemia (HAF) using dihydrotestosterone (DHT) that mimics many characteristics of women with PCOS. In the present study we tested the hypothesis that androgen-induced upregulation of the cytochrome P450 4A2 isoform (CYP4A2) and the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) in renal microvasculature contributes to the elevated BP in HAF rats. Female rats of SS.5BN consomic strain (wild type) rats and CYP4A2-/- rats on this same background were implanted with DHT (7.5mg/90d) or placebo pellets (n=5-8/grp) beginning at 6 wks of age; pellets were changed every 85 d. At 14 wks of age, rats were implanted with radiotelemetry transmitters, and mean arterial pressure (MAP) was measured for 10 days. Endogenous 20-HETE levels were measured using LC-MS in renal microvessels isolated using an Evans Blue sieving technique. DHT-treated HAF-SS.5BN rats had significantly higher MAP compared to placebo-SS.5BN (128±6 vs. 104±1 mmHg, p<0.004). In contrast, HAF-CYP4A2-/- rats had no change in MAP compared to placebo-CYP4A2-/- controls (120±4 vs 118±3 mmHg, p=NS). Endogenous 20-HETE levels in renal microvessels of HAF-SS.5BN rats were significantly increased compared to Placebo-SS.5BN (2.27±0.91 vs. 0.32±0.037 pmol/mg, p<0.01). The 20-HETE levels were lower in CYP4A2-/- than SS.5BN but DHT in HAF-CYP4A2-/- had no effect on 20-HETE levels compared to Placebo- CYP4A2-/-. These results suggest that androgen-mediated upregulation of the expression of CYP4A2 and the production of 20-HETE in renal microvessels contribute to elevated BP in HAF rats. These data also suggest that methods to attenuate 20-HETE may provide a novel therapeutic to reduce BP in women with PCOS. Work supported by NIH RO1HL66072 and PO1HL51971.

scholarly journals Response to Fujisawa: Elevated blood pressure in different populations: the role of dietary salt consumption

2012 ◽  
Vol 35 (9) ◽  
pp. 961-962
Author(s):  
Huynh Long Quan ◽  
Christopher Leigh Blizzard ◽  
Alison Jane Venn ◽  
James Edward Sharman
Keyword(s):  
Blood Pressure ◽  
Elevated Blood Pressure ◽  
Elevated Blood ◽  
Dietary Salt ◽  
Salt Consumption ◽  
Different Populations

Abstract P545: Insufficient Sleep and Nitric Oxide-Mediated Endothelium-Dependent Vasodilation in Adults With Elevated Blood Pressure

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Kelly A Stockelman ◽  
Anthony R Bain ◽  
Dana M Withrow ◽  
Tracey A Larson ◽  
Elizabeth M Boland ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Blood Pressure ◽  
Sleep Duration ◽  
Elevated Blood Pressure ◽  
Elevated Blood ◽  
Short Sleep Duration ◽  
Insufficient Sleep ◽  
Short Sleep ◽  
Normal Sleep

Elevated blood pressure (BP ≥130/80 mmHg) is associated with increased risk for myocardial infarction, heart failure, stroke and vascular disease. Insufficient nightly sleep (<7 h/night) has been linked not only to the etiology of elevated blood pressure but is a prevalent, often ignored, comorbidity. Indeed, short sleep duration is now considered to be a plausible risk factor for elevated blood pressure and a harbinger of increased cardiovascular risk. A high prevalence of insufficient nightly sleep has been reported in adults with elevated blood pressure. The influence of insufficient sleep on endothelial vasodilator function in adults with elevated blood pressure is unknown. We tested the hypotheses that chronic insufficient sleep is associated with diminished nitric oxide (NO)-mediated endothelium-dependent vasodilation in adults with elevated blood pressure. Moreover, the insufficient sleep-related reduction in endothelial vasodilator function is due, at least in part to increased oxidative stress. Thirty-five middle-aged and older adults with elevated blood pressure were studied: 15 with normal nightly sleep duration (11M/4F; age: 58±2 yr; BP: 136/82±1/2 mmHg; sleep: 7.6±0.2 h/night) and 20 with short nightly sleep duration (14M/6F; 58±1 yr; BP: 138/84±1/1 mmHg; sleep: 6.0±0.1 h/night). Forearm blood flow (FBF) responses to intra-arterial infusion of acetylcholine (ACh), in the absence and presence of the endothelial NO synthase inhibitor N G -monomethyl-L-arginine (L-NMMA) and the antioxidant vitamin C were determined by venous occlusion plethysmography. The FBF response to ACh was significantly lower (~20%) in the short sleep (from 3.8±0.2 to 11.0±0.6 ml/100 ml tissue/min) compared with the normal sleep duration group (from 4.2±0.2 to 13.6±0.6 ml/100 ml tissue/min). L-NMMA significantly reduced (~25%) the FBF response to ACh in the normal sleep but not the short sleep group. Vitamin C markedly increased (~35%; P<0.05) the vasodilator response to ACh in short sleepers only. In summary, habitual short sleep duration worsens NO-mediated endothelium-dependent vasodilation in adults with elevated blood pressure. Furthermore, the sleep-related diminishment in endothelial vasodilator function is due, in part, to increased oxidative stress.

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