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Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil.

Leong XF, Mustafa MR, Das S, Jaarin K - Lipids Health Dis (2010)

Bottom Line: Blood pressure increased significantly (p<0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups.Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration.As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.

ABSTRACT

Background: Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil.

Methods: Forty-two male Sprague-Dawley rats were equally divided into six groups: Group I (control)--normal rat chow, Group II--fresh soy oil, Group III--soy oil heated once, Group IV--soy oil heated twice, Group V--soy oil heated five times, Group VI--soy oil heated ten times. Blood pressure was measured at the baseline level and at a monthly interval for six months. Plasma nitric oxide, heme oxygenase and angiotensin-converting enzyme levels were measured prior to treatment, at month-three and month-six later. At the end of treatment, the rats were sacrificed and thoracic aortas were taken for measurement of vascular reactivity.

Results: Blood pressure increased significantly (p<0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups. Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration. Reheated soy oil groups exhibited attenuated relaxation in response to acetylcholine or sodium nitroprusside, and greater contraction to phenylephrine.

Conclusion: As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure.

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Related in: MedlinePlus

Effects of fresh and heated soy oil on vascular contraction in aortic rings. Shown are the contraction induced by phenylephrine (PE) in aortic rings isolated from rats fed with basal diet (control), fresh soy oil (FSO), soy oil heated once (1HSO), soy oil heated twice (2HSO), soy oil heated five times (5HSO) or soy oil heated ten times (10HSO) at different concentrations. Values are expressed as means ± S.E.M. (n = 7), p < 0.05 indicates significant difference compared to acontrol, bFSO group, c1HSO group, d2HSO group, e5HSO group.
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Figure 5: Effects of fresh and heated soy oil on vascular contraction in aortic rings. Shown are the contraction induced by phenylephrine (PE) in aortic rings isolated from rats fed with basal diet (control), fresh soy oil (FSO), soy oil heated once (1HSO), soy oil heated twice (2HSO), soy oil heated five times (5HSO) or soy oil heated ten times (10HSO) at different concentrations. Values are expressed as means ± S.E.M. (n = 7), p < 0.05 indicates significant difference compared to acontrol, bFSO group, c1HSO group, d2HSO group, e5HSO group.

Mentions: We also observed aortic ring contractions in response to increasing concentration of selective α1-adrenergic agonist PE. All aortic rings showed a concentration-dependent contraction (Fig. 5). Aortic rings of heated oil groups were susceptible to PE (p < 0.05). When tested at PE 10-5 M, a maximum contractile response of 120%, 131%, 145% and 172% of high K+ induced contraction for 1HSO, 2HSO, 5HSO and 10HSO groups, respectively, was recorded. Contraction effects remained similar for both the control (101%) and FSO (91%) groups.


Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil.

Leong XF, Mustafa MR, Das S, Jaarin K - Lipids Health Dis (2010)

Effects of fresh and heated soy oil on vascular contraction in aortic rings. Shown are the contraction induced by phenylephrine (PE) in aortic rings isolated from rats fed with basal diet (control), fresh soy oil (FSO), soy oil heated once (1HSO), soy oil heated twice (2HSO), soy oil heated five times (5HSO) or soy oil heated ten times (10HSO) at different concentrations. Values are expressed as means ± S.E.M. (n = 7), p < 0.05 indicates significant difference compared to acontrol, bFSO group, c1HSO group, d2HSO group, e5HSO group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2914008&req=5

Figure 5: Effects of fresh and heated soy oil on vascular contraction in aortic rings. Shown are the contraction induced by phenylephrine (PE) in aortic rings isolated from rats fed with basal diet (control), fresh soy oil (FSO), soy oil heated once (1HSO), soy oil heated twice (2HSO), soy oil heated five times (5HSO) or soy oil heated ten times (10HSO) at different concentrations. Values are expressed as means ± S.E.M. (n = 7), p < 0.05 indicates significant difference compared to acontrol, bFSO group, c1HSO group, d2HSO group, e5HSO group.
Mentions: We also observed aortic ring contractions in response to increasing concentration of selective α1-adrenergic agonist PE. All aortic rings showed a concentration-dependent contraction (Fig. 5). Aortic rings of heated oil groups were susceptible to PE (p < 0.05). When tested at PE 10-5 M, a maximum contractile response of 120%, 131%, 145% and 172% of high K+ induced contraction for 1HSO, 2HSO, 5HSO and 10HSO groups, respectively, was recorded. Contraction effects remained similar for both the control (101%) and FSO (91%) groups.

Bottom Line: Blood pressure increased significantly (p<0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups.Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration.As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.

ABSTRACT

Background: Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil.

Methods: Forty-two male Sprague-Dawley rats were equally divided into six groups: Group I (control)--normal rat chow, Group II--fresh soy oil, Group III--soy oil heated once, Group IV--soy oil heated twice, Group V--soy oil heated five times, Group VI--soy oil heated ten times. Blood pressure was measured at the baseline level and at a monthly interval for six months. Plasma nitric oxide, heme oxygenase and angiotensin-converting enzyme levels were measured prior to treatment, at month-three and month-six later. At the end of treatment, the rats were sacrificed and thoracic aortas were taken for measurement of vascular reactivity.

Results: Blood pressure increased significantly (p<0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups. Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration. Reheated soy oil groups exhibited attenuated relaxation in response to acetylcholine or sodium nitroprusside, and greater contraction to phenylephrine.

Conclusion: As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure.

Show MeSH
Related in: MedlinePlus