Expression of vascular endothelial growth factor in canine myocardium

Objective To observe the expression of vascular endothelial growth factor (VEGF) and VEGF mRNA in canine myocardium.Methods A progressive occlusion of the left anterior descending artery was produced in three weeks by surgical placement of an ameriod constrictor in a dog model.VEGF mRNA expression was examined using reverse transcriptase polymerase chain reaction (RT PCR) and positive cells of VEGF was assessed by immunohistochemical staining with polyclonal anti VEGF antibodies.Results The expression of mRNA coding the three isoforms VEGF 188 ,VEGF 164 and VEGF 120 was detectable in ischemic and non ischemic myocardium.The major isoforms were VEGF 188 and VEGF 164 (53% and 44% respectively),and the minor isoform was VEGF 120 .Positive VEGF expression was localized primarily in vascular smooth muscle cells.Conclusions Three isoforms of VEGF mRNA are expressed in the myocardium of dogs and the splicing patttern of VEGF mRNA will not be changed by ischmia.VEGF regulates function of the endothelial cells by a paracrine mechanism.