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Pulmonary exposure to carbon black nanoparticles and vascular effects.

Vesterdal LK, Folkmann JK, Jacobsen NR, Sheykhzade M, Wallin H, Loft S, Møller P - Part Fibre Toxicol (2010)

Bottom Line: Exposure to small size particulates is regarded as a risk factor for cardiovascular diseases.Exposure to nano-sized carbon black particles is associated with modest vasomotor impairment, which is associated neither with nitrosative stress nor with any obvious increases in the expression of cell adhesion proteins on endothelial cells or in plaque progression.Evidence of pulmonary inflammation was observed, but only in animals exposed to higher doses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark.

ABSTRACT

Background: Exposure to small size particulates is regarded as a risk factor for cardiovascular diseases.

Methods: We exposed young and aged apolipoprotein E knockout mice (apoE-/-) to carbon black (Printex 90, 14 nm) by intratracheal instillation, with different dosing and timing, and measured vasomotor function, progression of atherosclerotic plaques, and VCAM-1, ICAM-1, and 3-nitrotyrosine in blood vessels. The mRNA expression of VCAM-1, ICAM-1, HO-1, and MCP-1 was examined in lung tissue.

Results: Young apoE-/- mice exposed to two consecutive 0.5 mg/kg doses of carbon black exhibited lower acetylcholine-induced vasorelaxation in aorta segments mounted in myographs, whereas single doses of 0.05-2.7 mg/kg produced no such effects. The phenylephrine-dependent vasocontraction response was shifted toward a lower responsiveness in the mice exposed once to a low dose for 24 hours. No effects were seen on the progression of atherosclerotic plaques in the aged apoE-/- mice or on the expression of VCAM-1 and ICAM-1 and the presence of 3-nitrotyrosine in the vascular tissue of either young or aged apoE-/- mice. The expression of MCP-1 mRNA was increased in the lungs of young apoE-/- mice exposed to 0.9-2.7 mg/kg carbon black for 24 hours and of aged apoE-/- mice exposed to two consecutive 0.5 mg/kg doses of carbon black seven and five weeks prior to sacrifice.

Conclusion: Exposure to nano-sized carbon black particles is associated with modest vasomotor impairment, which is associated neither with nitrosative stress nor with any obvious increases in the expression of cell adhesion proteins on endothelial cells or in plaque progression. Evidence of pulmonary inflammation was observed, but only in animals exposed to higher doses.

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Progression of atherosclerotic plaques in a) aorta or b) brachiocephalic arteries (BCA) from 48-49 weeks old apoE-/- mice exposed to carbon black by i.t. instillation. In a) plaque area is expressed as % of intimal surface of aorta covered in plaques (left). The means are represented by horizontal lines (n = 11); each symbol represent the result from one animal. On the right, images are shown of the intimal surface of the aorta from the ascending aorta to the femoral arteries representative of the mean plaque areas in the control group (upper) and the exposed group (lower). The atherosclerotic plaques are discernible as white areas on the light grey background of normal aorta. In b) plaque area is expressed as % of lumen of BCA occupied by plaques (left). The means are represented by horizontal lines (n = 7); each symbol represent the result from one animal. On the right, images are shown of BCA sections representative of the means in the control group (left) and the exposed group (right).
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Figure 4: Progression of atherosclerotic plaques in a) aorta or b) brachiocephalic arteries (BCA) from 48-49 weeks old apoE-/- mice exposed to carbon black by i.t. instillation. In a) plaque area is expressed as % of intimal surface of aorta covered in plaques (left). The means are represented by horizontal lines (n = 11); each symbol represent the result from one animal. On the right, images are shown of the intimal surface of the aorta from the ascending aorta to the femoral arteries representative of the mean plaque areas in the control group (upper) and the exposed group (lower). The atherosclerotic plaques are discernible as white areas on the light grey background of normal aorta. In b) plaque area is expressed as % of lumen of BCA occupied by plaques (left). The means are represented by horizontal lines (n = 7); each symbol represent the result from one animal. On the right, images are shown of BCA sections representative of the means in the control group (left) and the exposed group (right).

Mentions: Plaque area was determined on the intimal surface of whole aorta of aged mice which received two doses of 0.5 mg/kg CB or vehicle 7 and 5 weeks prior to sacrifice. There was no significant difference in plaque area between the CB exposed group and the control group (Figure 4a). Correspondingly, the plaque area determined in the cross sections of the BCA from the same mice did not show any difference between the CB exposed group and the control group (Figure 4b).


Pulmonary exposure to carbon black nanoparticles and vascular effects.

Vesterdal LK, Folkmann JK, Jacobsen NR, Sheykhzade M, Wallin H, Loft S, Møller P - Part Fibre Toxicol (2010)

Progression of atherosclerotic plaques in a) aorta or b) brachiocephalic arteries (BCA) from 48-49 weeks old apoE-/- mice exposed to carbon black by i.t. instillation. In a) plaque area is expressed as % of intimal surface of aorta covered in plaques (left). The means are represented by horizontal lines (n = 11); each symbol represent the result from one animal. On the right, images are shown of the intimal surface of the aorta from the ascending aorta to the femoral arteries representative of the mean plaque areas in the control group (upper) and the exposed group (lower). The atherosclerotic plaques are discernible as white areas on the light grey background of normal aorta. In b) plaque area is expressed as % of lumen of BCA occupied by plaques (left). The means are represented by horizontal lines (n = 7); each symbol represent the result from one animal. On the right, images are shown of BCA sections representative of the means in the control group (left) and the exposed group (right).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2991279&req=5

Figure 4: Progression of atherosclerotic plaques in a) aorta or b) brachiocephalic arteries (BCA) from 48-49 weeks old apoE-/- mice exposed to carbon black by i.t. instillation. In a) plaque area is expressed as % of intimal surface of aorta covered in plaques (left). The means are represented by horizontal lines (n = 11); each symbol represent the result from one animal. On the right, images are shown of the intimal surface of the aorta from the ascending aorta to the femoral arteries representative of the mean plaque areas in the control group (upper) and the exposed group (lower). The atherosclerotic plaques are discernible as white areas on the light grey background of normal aorta. In b) plaque area is expressed as % of lumen of BCA occupied by plaques (left). The means are represented by horizontal lines (n = 7); each symbol represent the result from one animal. On the right, images are shown of BCA sections representative of the means in the control group (left) and the exposed group (right).
Mentions: Plaque area was determined on the intimal surface of whole aorta of aged mice which received two doses of 0.5 mg/kg CB or vehicle 7 and 5 weeks prior to sacrifice. There was no significant difference in plaque area between the CB exposed group and the control group (Figure 4a). Correspondingly, the plaque area determined in the cross sections of the BCA from the same mice did not show any difference between the CB exposed group and the control group (Figure 4b).

Bottom Line: Exposure to small size particulates is regarded as a risk factor for cardiovascular diseases.Exposure to nano-sized carbon black particles is associated with modest vasomotor impairment, which is associated neither with nitrosative stress nor with any obvious increases in the expression of cell adhesion proteins on endothelial cells or in plaque progression.Evidence of pulmonary inflammation was observed, but only in animals exposed to higher doses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark.

ABSTRACT

Background: Exposure to small size particulates is regarded as a risk factor for cardiovascular diseases.

Methods: We exposed young and aged apolipoprotein E knockout mice (apoE-/-) to carbon black (Printex 90, 14 nm) by intratracheal instillation, with different dosing and timing, and measured vasomotor function, progression of atherosclerotic plaques, and VCAM-1, ICAM-1, and 3-nitrotyrosine in blood vessels. The mRNA expression of VCAM-1, ICAM-1, HO-1, and MCP-1 was examined in lung tissue.

Results: Young apoE-/- mice exposed to two consecutive 0.5 mg/kg doses of carbon black exhibited lower acetylcholine-induced vasorelaxation in aorta segments mounted in myographs, whereas single doses of 0.05-2.7 mg/kg produced no such effects. The phenylephrine-dependent vasocontraction response was shifted toward a lower responsiveness in the mice exposed once to a low dose for 24 hours. No effects were seen on the progression of atherosclerotic plaques in the aged apoE-/- mice or on the expression of VCAM-1 and ICAM-1 and the presence of 3-nitrotyrosine in the vascular tissue of either young or aged apoE-/- mice. The expression of MCP-1 mRNA was increased in the lungs of young apoE-/- mice exposed to 0.9-2.7 mg/kg carbon black for 24 hours and of aged apoE-/- mice exposed to two consecutive 0.5 mg/kg doses of carbon black seven and five weeks prior to sacrifice.

Conclusion: Exposure to nano-sized carbon black particles is associated with modest vasomotor impairment, which is associated neither with nitrosative stress nor with any obvious increases in the expression of cell adhesion proteins on endothelial cells or in plaque progression. Evidence of pulmonary inflammation was observed, but only in animals exposed to higher doses.

Show MeSH
Related in: MedlinePlus