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Lymphangiogenesis in myocardial remodelling after infarction.

Ishikawa Y, Akishima-Fukasawa Y, Ito K, Akasaka Y, Tanaka M, Shimokawa R, Kimura-Matsumoto M, Morita H, Sato S, Kamata I, Ishii T - Histopathology (2007)

Bottom Line: BD decreased with advance of myocardial necrosis, subsequently increased at the early stage of granulation and thereafter decreased with the progression of scar formation.Vascular endothelial growth factor-C was consistently expressed in viable cardiomyocytes around the lesion in all of these stages.In myocardial remodelling after MI, lymphangiogenesis lags behind blood vessel angiogenesis; newly formed lymphatics may be involved mainly in the maturation of fibrosis and scar formation through the drainage of excessive proteins and fluid.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Toho University School of Medicine, Tokyo, Japan. yukio@med.toho-u.ac.jp

ABSTRACT

Aims: The lymphatic system is involved in fluid homeostasis of the cardiac interstitium, but lymphangiogenesis in myocardial remodelling has not previously been examined histopathologically. The aim was to investigate by D2-40 immunohistochemistry the sequential changes in lymphatic distribution in the process of myocardial remodelling after myocardial infarction (MI).

Methods and results: Myocardial tissues in various phases of healing after MI were obtained from 40 autopsied hearts. D2-40+ lymphatic vessel density (LD) and CD34+ blood vessel density (BD) in the lesion were determined. BD decreased with advance of myocardial necrosis, subsequently increased at the early stage of granulation and thereafter decreased with the progression of scar formation. In contrast, lymphatic vessels were not detected in lesions with coagulation necrosis, and newly formed lymphatics first appeared in the early stages of granulation. A subsequent increase in LD was demonstrated in the late stages of granulation, and lymphatics remained up to the scar phase. Vascular endothelial growth factor-C was consistently expressed in viable cardiomyocytes around the lesion in all of these stages.

Conclusion: In myocardial remodelling after MI, lymphangiogenesis lags behind blood vessel angiogenesis; newly formed lymphatics may be involved mainly in the maturation of fibrosis and scar formation through the drainage of excessive proteins and fluid.

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Related in: MedlinePlus

Immunohistochemistry in Stages I (a,b), IV (c) and V (d) a, A D2-40+ lymphatic vessel is recognized in the interstitium of the lesion with wavy myocardial fibres (Stage I). b, The upper half of the figure shows wavy myocardial fibres which are strongly positive for vascular endothelial growth factor-C (VEGF-C). Cardiomyocytes around the lesion (the lower half of the figure) are also weakly immunopositive for VEGF-C. c, In Stage IV, showing the early change of granulation, a small D2-40+ lymphatic vessel (arrow) is shown in the vicinity of the viable cardiomyocytes (the left upper area of the figure). d, In Stage V, showing the mature granulation phase with infiltration of macrophages and lymphocytes, D2-40+ lymphatics (arrows) are scattered. A lymphatic vessel in the centre of the figure contains lymphocytes in the lumen. Arrowheads indicate muscular blood vessels.
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fig02: Immunohistochemistry in Stages I (a,b), IV (c) and V (d) a, A D2-40+ lymphatic vessel is recognized in the interstitium of the lesion with wavy myocardial fibres (Stage I). b, The upper half of the figure shows wavy myocardial fibres which are strongly positive for vascular endothelial growth factor-C (VEGF-C). Cardiomyocytes around the lesion (the lower half of the figure) are also weakly immunopositive for VEGF-C. c, In Stage IV, showing the early change of granulation, a small D2-40+ lymphatic vessel (arrow) is shown in the vicinity of the viable cardiomyocytes (the left upper area of the figure). d, In Stage V, showing the mature granulation phase with infiltration of macrophages and lymphocytes, D2-40+ lymphatics (arrows) are scattered. A lymphatic vessel in the centre of the figure contains lymphocytes in the lumen. Arrowheads indicate muscular blood vessels.

Mentions: The interstitium in this lesion was oedematous and included a few D2-40+ lymphatic capillaries (Figure 2a), but the number of lymphatics seemed to be decreased compared with that in the normal myocardium. VEGF-C was weakly expressed in the viable cardiomyocytes around the lesion as well as being strongly expressed in the affected cardiomyocytes (Figure 2b).


Lymphangiogenesis in myocardial remodelling after infarction.

Ishikawa Y, Akishima-Fukasawa Y, Ito K, Akasaka Y, Tanaka M, Shimokawa R, Kimura-Matsumoto M, Morita H, Sato S, Kamata I, Ishii T - Histopathology (2007)

Immunohistochemistry in Stages I (a,b), IV (c) and V (d) a, A D2-40+ lymphatic vessel is recognized in the interstitium of the lesion with wavy myocardial fibres (Stage I). b, The upper half of the figure shows wavy myocardial fibres which are strongly positive for vascular endothelial growth factor-C (VEGF-C). Cardiomyocytes around the lesion (the lower half of the figure) are also weakly immunopositive for VEGF-C. c, In Stage IV, showing the early change of granulation, a small D2-40+ lymphatic vessel (arrow) is shown in the vicinity of the viable cardiomyocytes (the left upper area of the figure). d, In Stage V, showing the mature granulation phase with infiltration of macrophages and lymphocytes, D2-40+ lymphatics (arrows) are scattered. A lymphatic vessel in the centre of the figure contains lymphocytes in the lumen. Arrowheads indicate muscular blood vessels.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2366023&req=5

fig02: Immunohistochemistry in Stages I (a,b), IV (c) and V (d) a, A D2-40+ lymphatic vessel is recognized in the interstitium of the lesion with wavy myocardial fibres (Stage I). b, The upper half of the figure shows wavy myocardial fibres which are strongly positive for vascular endothelial growth factor-C (VEGF-C). Cardiomyocytes around the lesion (the lower half of the figure) are also weakly immunopositive for VEGF-C. c, In Stage IV, showing the early change of granulation, a small D2-40+ lymphatic vessel (arrow) is shown in the vicinity of the viable cardiomyocytes (the left upper area of the figure). d, In Stage V, showing the mature granulation phase with infiltration of macrophages and lymphocytes, D2-40+ lymphatics (arrows) are scattered. A lymphatic vessel in the centre of the figure contains lymphocytes in the lumen. Arrowheads indicate muscular blood vessels.
Mentions: The interstitium in this lesion was oedematous and included a few D2-40+ lymphatic capillaries (Figure 2a), but the number of lymphatics seemed to be decreased compared with that in the normal myocardium. VEGF-C was weakly expressed in the viable cardiomyocytes around the lesion as well as being strongly expressed in the affected cardiomyocytes (Figure 2b).

Bottom Line: BD decreased with advance of myocardial necrosis, subsequently increased at the early stage of granulation and thereafter decreased with the progression of scar formation.Vascular endothelial growth factor-C was consistently expressed in viable cardiomyocytes around the lesion in all of these stages.In myocardial remodelling after MI, lymphangiogenesis lags behind blood vessel angiogenesis; newly formed lymphatics may be involved mainly in the maturation of fibrosis and scar formation through the drainage of excessive proteins and fluid.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Toho University School of Medicine, Tokyo, Japan. yukio@med.toho-u.ac.jp

ABSTRACT

Aims: The lymphatic system is involved in fluid homeostasis of the cardiac interstitium, but lymphangiogenesis in myocardial remodelling has not previously been examined histopathologically. The aim was to investigate by D2-40 immunohistochemistry the sequential changes in lymphatic distribution in the process of myocardial remodelling after myocardial infarction (MI).

Methods and results: Myocardial tissues in various phases of healing after MI were obtained from 40 autopsied hearts. D2-40+ lymphatic vessel density (LD) and CD34+ blood vessel density (BD) in the lesion were determined. BD decreased with advance of myocardial necrosis, subsequently increased at the early stage of granulation and thereafter decreased with the progression of scar formation. In contrast, lymphatic vessels were not detected in lesions with coagulation necrosis, and newly formed lymphatics first appeared in the early stages of granulation. A subsequent increase in LD was demonstrated in the late stages of granulation, and lymphatics remained up to the scar phase. Vascular endothelial growth factor-C was consistently expressed in viable cardiomyocytes around the lesion in all of these stages.

Conclusion: In myocardial remodelling after MI, lymphangiogenesis lags behind blood vessel angiogenesis; newly formed lymphatics may be involved mainly in the maturation of fibrosis and scar formation through the drainage of excessive proteins and fluid.

Show MeSH
Related in: MedlinePlus