TUMOR-NECROSIS-FACTOR-ALPHA IS EXPRESSED BY MONOCYTES MACROPHAGES FOLLOWING CARDIAC MICROEMBOLIZATION AND IS ANTAGONIZED BY CYCLOSPORINE/

Citation
M. Arras et al., TUMOR-NECROSIS-FACTOR-ALPHA IS EXPRESSED BY MONOCYTES MACROPHAGES FOLLOWING CARDIAC MICROEMBOLIZATION AND IS ANTAGONIZED BY CYCLOSPORINE/, Basic research in cardiology, 93(2), 1998, pp. 97-107
Citations number
60
Categorie Soggetti
Cardiac & Cardiovascular System
ISSN journal
03008428
Volume
93
Issue
2
Year of publication
1998
Pages
97 - 107
Database
ISI
SICI code
0300-8428(1998)93:2<97:TIEBMM>2.0.ZU;2-O
Abstract
The time course of expression of TNF-alpha in myocardial wound healing following ischemic injury was investigated in the porcine heart. Micr oembolization was used to induce focal ischemia and necrosis in hearts of 39 adult pigs. The animals were sacrified after 3, 6, 12, 24 h, 3 and 7 days, and after 4 weeks, and the myocardial tissue was studied b y immunofluorescence using specific antibodies. TNF-alpha containing c ells were identified as monocytes/macrophages by double staining with a muramidase antibody. Monocytes/macrophages were the only source of T NF-alpha. Microembolization caused multiple necrotic foci with loss of myocytes in the left ventricular myocardium. These foci contained num erous monocytes/macrophages and showed an inflammatory reaction typica l of wound healing followed by replacement with scar tissue. The numbe r of TNF-alpha positive cells increased after 24 h, peaked between 3-7 days and slowly decreased thereafter. Expression of TNF-alpha in mono cytes/macrophages was significantly reduced after pretreatment of pigs with cyclosporine or dexamethasone. It is concluded that 1.) in myoca rdial tissue monocytes/macrophages are the only cell type expressing T NF-alpha, 2.) TNF-alpha is involved in wound healing after ischemia, a nd 3.) synthesis of TNF-alpha and inflammatory angiogenesis can be inh ibited be treatment with either cyclosporine or dexamethasone.