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Aorta remodeling responses to distinct atherogenic stimuli: hypertension, hypercholesterolemia and turbulent flow/low wall shear stress.

Prado CM, Rossi MA - Open Cardiovasc Med J (2008)

Bottom Line: This review is based on recently published data from our laboratory.We investigated the role of hypertension and laminar flow, hypercholesterolemia and laminar flow and turbulent blood flow/low wall shear stress, and turbulent blood flow/low wall shear stress associated with hypercholesterolemia on aorta remodeling of rats feeding normal diet or hypercholesterolemic diet.Our findings suggest that increased circumferential wall tension due to hypertension plays a key role in the remodeling through biomechanical effects on oxidative stress and increased TGF-beta expression; the remodeling observed in the presence of hypercholesterolemia could be initiated by oxidative stress that is involved in several processes of atherogenesis and this remodeling is more pronounced in the presence of turbulent blood flow/low wall shear stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, S.P., Brazil.

ABSTRACT
This review is based on recently published data from our laboratory. We investigated the role of hypertension and laminar flow, hypercholesterolemia and laminar flow and turbulent blood flow/low wall shear stress, and turbulent blood flow/low wall shear stress associated with hypercholesterolemia on aorta remodeling of rats feeding normal diet or hypercholesterolemic diet. Our findings suggest that increased circumferential wall tension due to hypertension plays a key role in the remodeling through biomechanical effects on oxidative stress and increased TGF-beta expression; the remodeling observed in the presence of hypercholesterolemia could be initiated by oxidative stress that is involved in several processes of atherogenesis and this remodeling is more pronounced in the presence of turbulent blood flow/low wall shear stress.

No MeSH data available.


Related in: MedlinePlus

High resolution light microscopy. Representative views of the aortas from sham-operated (A), prestenosis (C), poststenosis (E), sham-operated+HD (B), prestenosis+HD (D) and poststenosis+HD (F). Panel C. Intimal thickening with enlarged endothelial cells and diffusely distributed neointimal plaques composed of smooth muscle cells and occasional mononuclear cells with collagen and elastic fibers surrounding them and medial thickening can be seen, contrasting with the delicate structure of the intima in the sham-operated group (A). Panel E. Intima appeared delicate quite similar to the intima in the sham-operated, except for focally distributed neointimal plaques similar to those observed in the prestenotic segment but many of them larger in size. Aortas from sham-operated+HD (Panel B) and operated+HD (Panel D) revealed diffusely distributed foci of small flat lesions corresponding microscopically to fatty streaks characterized by intimal foam cells accumulation, contrasting with the delicate structure of the intima in the sham-operated group. Panel F. Focally distributed incipient atherosclerotic lesions characterized by raised focal lesions within the intima composed of smooth muscle cells, mononuclear cells and extracellular matrix were seen in this segment. When the percentile frequency distribution of intima thickness in the prestenotic segment of all groups was plotted, it can be clearly seen the shift to the right of the values of operated group and in comparison with the values in corresponding segment in sham-operated animals (G). The percentile frequency distribution of intimal thickness in the poststenotic segment of sham-operated+HD, operated group and operated+HD was quite similar to that observed in corresponding areas of sham-operated group, except for the clear demonstrations of the occurrence of marked intimal thickening in the operated group and operated+HD (H). Scale bars, 40 µ m.
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Figure 3: High resolution light microscopy. Representative views of the aortas from sham-operated (A), prestenosis (C), poststenosis (E), sham-operated+HD (B), prestenosis+HD (D) and poststenosis+HD (F). Panel C. Intimal thickening with enlarged endothelial cells and diffusely distributed neointimal plaques composed of smooth muscle cells and occasional mononuclear cells with collagen and elastic fibers surrounding them and medial thickening can be seen, contrasting with the delicate structure of the intima in the sham-operated group (A). Panel E. Intima appeared delicate quite similar to the intima in the sham-operated, except for focally distributed neointimal plaques similar to those observed in the prestenotic segment but many of them larger in size. Aortas from sham-operated+HD (Panel B) and operated+HD (Panel D) revealed diffusely distributed foci of small flat lesions corresponding microscopically to fatty streaks characterized by intimal foam cells accumulation, contrasting with the delicate structure of the intima in the sham-operated group. Panel F. Focally distributed incipient atherosclerotic lesions characterized by raised focal lesions within the intima composed of smooth muscle cells, mononuclear cells and extracellular matrix were seen in this segment. When the percentile frequency distribution of intima thickness in the prestenotic segment of all groups was plotted, it can be clearly seen the shift to the right of the values of operated group and in comparison with the values in corresponding segment in sham-operated animals (G). The percentile frequency distribution of intimal thickness in the poststenotic segment of sham-operated+HD, operated group and operated+HD was quite similar to that observed in corresponding areas of sham-operated group, except for the clear demonstrations of the occurrence of marked intimal thickening in the operated group and operated+HD (H). Scale bars, 40 µ m.

Mentions: Aortas from operated group demonstrated in the hypertensive prestenotic segment changes characterized by intimal thickening with enlarged endothelial cells and diffusely distributed neointimal plaques composed of smooth muscle cells and occasional mononuclear cells with collagen and elastic fibers surrounding them and medial thickening (Fig. 3C), contrasting with the delicate structure of the intima in the sham-operated group (Fig. 3A). Aortas from sham-operated+HD (Fig. 3B) and operated+HD (Fig. 3D) revealed diffusely distributed foci of small flat lesions corresponding microscopically to fatty streaks characterized by intimal foam cells accumulation, contrasting with the delicate structure of the intima in the sham-operated group. When the percentile frequency distribution of intima thickness in the prestenotic segment of all groups was plotted, it can be clearly seen the shift to the right of the values of operated group and in comparison with the values in corresponding segment in sham-operated animals. The diffuse intimal thickening and diffusely neointimal plaques observed in the operated group and the small flat lesions observed in sham-operated+HD and operated+HD can be evidenced (Fig. 3G).


Aorta remodeling responses to distinct atherogenic stimuli: hypertension, hypercholesterolemia and turbulent flow/low wall shear stress.

Prado CM, Rossi MA - Open Cardiovasc Med J (2008)

High resolution light microscopy. Representative views of the aortas from sham-operated (A), prestenosis (C), poststenosis (E), sham-operated+HD (B), prestenosis+HD (D) and poststenosis+HD (F). Panel C. Intimal thickening with enlarged endothelial cells and diffusely distributed neointimal plaques composed of smooth muscle cells and occasional mononuclear cells with collagen and elastic fibers surrounding them and medial thickening can be seen, contrasting with the delicate structure of the intima in the sham-operated group (A). Panel E. Intima appeared delicate quite similar to the intima in the sham-operated, except for focally distributed neointimal plaques similar to those observed in the prestenotic segment but many of them larger in size. Aortas from sham-operated+HD (Panel B) and operated+HD (Panel D) revealed diffusely distributed foci of small flat lesions corresponding microscopically to fatty streaks characterized by intimal foam cells accumulation, contrasting with the delicate structure of the intima in the sham-operated group. Panel F. Focally distributed incipient atherosclerotic lesions characterized by raised focal lesions within the intima composed of smooth muscle cells, mononuclear cells and extracellular matrix were seen in this segment. When the percentile frequency distribution of intima thickness in the prestenotic segment of all groups was plotted, it can be clearly seen the shift to the right of the values of operated group and in comparison with the values in corresponding segment in sham-operated animals (G). The percentile frequency distribution of intimal thickness in the poststenotic segment of sham-operated+HD, operated group and operated+HD was quite similar to that observed in corresponding areas of sham-operated group, except for the clear demonstrations of the occurrence of marked intimal thickening in the operated group and operated+HD (H). Scale bars, 40 µ m.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
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Figure 3: High resolution light microscopy. Representative views of the aortas from sham-operated (A), prestenosis (C), poststenosis (E), sham-operated+HD (B), prestenosis+HD (D) and poststenosis+HD (F). Panel C. Intimal thickening with enlarged endothelial cells and diffusely distributed neointimal plaques composed of smooth muscle cells and occasional mononuclear cells with collagen and elastic fibers surrounding them and medial thickening can be seen, contrasting with the delicate structure of the intima in the sham-operated group (A). Panel E. Intima appeared delicate quite similar to the intima in the sham-operated, except for focally distributed neointimal plaques similar to those observed in the prestenotic segment but many of them larger in size. Aortas from sham-operated+HD (Panel B) and operated+HD (Panel D) revealed diffusely distributed foci of small flat lesions corresponding microscopically to fatty streaks characterized by intimal foam cells accumulation, contrasting with the delicate structure of the intima in the sham-operated group. Panel F. Focally distributed incipient atherosclerotic lesions characterized by raised focal lesions within the intima composed of smooth muscle cells, mononuclear cells and extracellular matrix were seen in this segment. When the percentile frequency distribution of intima thickness in the prestenotic segment of all groups was plotted, it can be clearly seen the shift to the right of the values of operated group and in comparison with the values in corresponding segment in sham-operated animals (G). The percentile frequency distribution of intimal thickness in the poststenotic segment of sham-operated+HD, operated group and operated+HD was quite similar to that observed in corresponding areas of sham-operated group, except for the clear demonstrations of the occurrence of marked intimal thickening in the operated group and operated+HD (H). Scale bars, 40 µ m.
Mentions: Aortas from operated group demonstrated in the hypertensive prestenotic segment changes characterized by intimal thickening with enlarged endothelial cells and diffusely distributed neointimal plaques composed of smooth muscle cells and occasional mononuclear cells with collagen and elastic fibers surrounding them and medial thickening (Fig. 3C), contrasting with the delicate structure of the intima in the sham-operated group (Fig. 3A). Aortas from sham-operated+HD (Fig. 3B) and operated+HD (Fig. 3D) revealed diffusely distributed foci of small flat lesions corresponding microscopically to fatty streaks characterized by intimal foam cells accumulation, contrasting with the delicate structure of the intima in the sham-operated group. When the percentile frequency distribution of intima thickness in the prestenotic segment of all groups was plotted, it can be clearly seen the shift to the right of the values of operated group and in comparison with the values in corresponding segment in sham-operated animals. The diffuse intimal thickening and diffusely neointimal plaques observed in the operated group and the small flat lesions observed in sham-operated+HD and operated+HD can be evidenced (Fig. 3G).

Bottom Line: This review is based on recently published data from our laboratory.We investigated the role of hypertension and laminar flow, hypercholesterolemia and laminar flow and turbulent blood flow/low wall shear stress, and turbulent blood flow/low wall shear stress associated with hypercholesterolemia on aorta remodeling of rats feeding normal diet or hypercholesterolemic diet.Our findings suggest that increased circumferential wall tension due to hypertension plays a key role in the remodeling through biomechanical effects on oxidative stress and increased TGF-beta expression; the remodeling observed in the presence of hypercholesterolemia could be initiated by oxidative stress that is involved in several processes of atherogenesis and this remodeling is more pronounced in the presence of turbulent blood flow/low wall shear stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, S.P., Brazil.

ABSTRACT
This review is based on recently published data from our laboratory. We investigated the role of hypertension and laminar flow, hypercholesterolemia and laminar flow and turbulent blood flow/low wall shear stress, and turbulent blood flow/low wall shear stress associated with hypercholesterolemia on aorta remodeling of rats feeding normal diet or hypercholesterolemic diet. Our findings suggest that increased circumferential wall tension due to hypertension plays a key role in the remodeling through biomechanical effects on oxidative stress and increased TGF-beta expression; the remodeling observed in the presence of hypercholesterolemia could be initiated by oxidative stress that is involved in several processes of atherogenesis and this remodeling is more pronounced in the presence of turbulent blood flow/low wall shear stress.

No MeSH data available.


Related in: MedlinePlus