Objective:This study was to investigate the interrelations between the acetylase activity and specialization rate of the differentiation of MSCs to the cardiac cells when histon deacetylase enzyme inhibitor trichostatin A (TSA)interferes in the cardiac cells. Method: MSCs of ratswere separated

The already labeled MSCs and cardiac muscle cells were put respectively into the MSCs interfered by different concentrations of TSA cultivated in mix tune with cardiac muscles. Adding TSA into the conventional culture of MSCs for the negative group.One week later

with the help of immunofluorescence

detecting the expression of the function proteinum

ie. myosin heavy chain (MHC)and Connexin43 (Cx43)

of the cardiac muscle constitution in MSCs was detected. Results: ① There appeared sample differentiation of the cardiac muscle cells after the coculture of the MSCs and the pulsating cardiac muscle cells for one week

and the expression of the function proteinum of the cardiac muscle constitution;② In the positive group

in the mix culture of the cardiac muscle cells and the MSCs in which the TSA interfered for 48 h

there appeard sample differentiation of the cardiac muscle cells;③ In the negative group

part of the MSCs could express the function proteinum of the cardiac muscle constitution. During the 7 days of coculture

with the induction of TSA

MSCs was double-labeled by Brdu-DAPI. The differentiation rate of the fluorescent manifestation of the MHC and Cx43 in the MSCs was notably different expression that in the positive group

Conclusion: MSCs in which HDAC

the enzyme inhibitor

interferes are in the microenvironment of the cardiac muscle cells. HDAC

the enzyme inhibitor

functions as a promotion factor in the specialization of MSCs

suggesting the interrelation between the acetylase activity and the cell specialization rates.