title: Immunohistochemical demonstration of 15-lipoxygenase in transplant coronary artery disease.
abstract: 15-Lipoxygenase (15-LO) catalyzes the oxygenation of arachidonic and linoleic acids and has been implicated in the oxidative modification of low-density lipoproteins (LDL). 15-LO mRNA and protein have previously been demonstrated in macrophages of rabbit and human atherosclerotic lesions. The purpose of this study was to investigate whether 15-LO is also present in the accelerated form of coronary artery disease that can complicate cardiac transplantation (TCAD). Immunohistochemical analysis of coronary arteries with TCAD was carried out by using a rabbit polyclonal antibody raised against human recombinant 15-LO and an avidin-biotin-immunoperoxidase system. Normal coronary and pulmonary arteries showed no immunostaining for 15-LO. Two different types of TCAD were observed. One type consisted of concentric intimal proliferation of smooth muscle cells, without lipid or calcium deposits. No immunoreactivity for 15-LO was present in these lesions. The second type of graft arteriosclerosis consisted of complex atheromatous lesions, containing myointimal cells, lipid-laden foam cells, fragmented internal elastic laminae, and calcifications. 15-LO immunostaining of myointimal cells, lipid-laden foam cells, and endothelial cells was consistently present in these atheromatous lesions. The majority of the myointimal and foam cells positive for 15-LO were recognized by antisera to alpha-smooth muscle actin; the others were identified as macrophages. The results indicate that 15-LO expression is present in endothelial, myointimal, and foam cells in complex atheromatous lesions of TCAD, and suggest that 15-LO may play a role in the pathogenesis of this form of the disease.
authors.affiliation: Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ravalli
authors.forename: C C
authors.initials: CC
authors.lastname: Marboe
authors.forename: V D
authors.initials: VD
authors.lastname: D'Agati
authors.forename: R E
authors.initials: RE
authors.lastname: Michler
authors.forename: E
authors.initials: E
authors.lastname: Sigal
authors.forename: P J
authors.initials: PJ
authors.lastname: Cannon
mesh_terms: D000328:Adult; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000201:enzymology* / Q000209:etiology* / Q000473:pathology; D003331:Coronary Vessels / Q000201:enzymology* / Q000473:pathology; D016027:Heart Transplantation; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011183:Postoperative Complications; D012016:Reference Values
chemical_list: D001093:Arachidonate 15-Lipoxygenase