Age-related Changes of MHC Class II Positive Dendritic Cells in Cardiac Muscle of Rat / 체질인류학회지

ABSTRACT

Cardiac dendritic cells are considered to play an important role in the immunoresponse of the heart. However, It is unknown that changes of shapes and numbers of these cells in the heart. The aim of this study is to reveal age-related changes of MHC class II positive dendritic cells in cardiac muscle of rat. Male Sprague-Dawley rats (1 month, 12 months, and 24 months old) were used in this study. Animals were deeply anesthetized with 3.5% chloral hydrate (1 mL/100 g) and hearts removed. Immunostaining was done according to standard methods used routinely. In brief, tissue sections were incubated with primary antibodies generated in mouse anti-rat MHC class II antibody for single immunostains. Tissue sections were observed by using light microscope and dendritic cells were counted. Average numbers of MHC class II-positive dendritic cells were 1.4 cells per unit area (0.2 mm2) at 1 month old rat, 2.8 cells at 12 months old rat, and 4.6 cells at 24 months old rat, and then numbers of dendritic cells were increased according to ages. According as age increases, cytoplasmic processes of MHC class II-immunoreactive dendritic cells became longer and more complex and aggregated together. It's suggested that age-related changes of MHC class II positive dendritic cells in the cardiac muscle would be related to immunity.