OBJECTIVETo study the growth and differentiation of adult canine autologous skeletal myoblasts after being transplanted into acute myocardial infarction (AMI) region by intramyocardium injection (IMI) and intracoronary infusion (ICI).

METHODSAutologous skeletal myoblasts were procured by a modified method. AMI model of adult canine was obtained through left anterior descending branch ligation and was divided into 4 groups (n = 5 for each group). Autologous skeletal myoblasts (1.0 - 1.4 x 10(8) cells) were injected locally into AMI region or infused into infarction-related coronary artery. Specimens were harvested 4 weeks after cellular transplantation for histological study including HE, PTH, immunochemical stain and transmission electronmicroscope.

RESULTSIn both two transplantation groups, newborn muscle-derived cells, striated muscle tissue and mature skeletal myofibril were demonstrated existing in MI region by electronmicroscope, PTH stain or anti-skeletal myosin heavy chain (slow) immunochemical stain, respectively. Newborn striated muscle tissues arranged in order of consistency with host myocardial fibers in two treatment groups. Newborn striated muscle tissue was more inclined to gather in MI region in the local injection group but distracted from each other in the intracoronary infusion group.

CONCLUSIONAutologous skeletal myoblasts appears to live and differentiate into mature striated muscle tissue after transplanting into AMI region by IMI or ICI routes.