ISSN:
1432-0878
Keywords:
Key words: Mitosis
;
Gene expression
;
Histone H3
;
PCNA (proliferating cell nuclear antigen)
;
Microembolization
;
Angiogenesis
;
Pig (Landrace)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract. In ischaemic porcine myocardium, the growth of collateral vessels by angiogenesis is observed in clusters in the vicinity of focal necroses. Because mitosis of endothelial cells is a prerequisite for angiogenesis, the purpose of this study has been to evaluate the time course of mitosis as an indicator of vascular growth in a porcine model of coronary microembolization. Ischaemia was induced by injection of 25-µm microspheres in the left circumflex artery, followed by tissue collection from non-ischaemic and ischaemic areas of the same heart after 24, 72 or 168 h microembolization. Tissue was studied by histone H3 in-situ hybridization, PCNA/cyclin immunohistochemistry and electron microscopy. The number of blood vessels in ischaemic myocardium was compared with that in normal control tissue. Capillary growth started as early as 24 h after microembolization, as indicated by increasing numbers of proliferating, histone H3- and PCNA/cyclin-positive cells in the necrotic inflammatory foci of the ischaemic area. At 72 h and 168 h, the number of blood vessels was significantly higher in ischaemic than in normal myocardium, whereas at 168 h, mitosis of cells was, as in normal myocardium, a rare event. Coronary microembolization of porcine myocardium thus leads to an increased cellular proliferation rate between 24 h and less than 7 days after the onset of microembolization, followed by enhanced capillary growth. In-situ hybridization with histone H3 and PCNA/cyclin immunohistochemistry seem to be reliable markers for proliferation and vascular growth in non-cancerogenic tissue.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004410050781
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