SUSPENSION-CULTURE OF DIFFERENTIATED RAT-HEART MYOCYTES ON NONADHESIVE SURFACES

Cardiac myocytes isolated from adult rat ventricles have been maintain ed in a stable, differentiated state for prolonged periods by the use of suspension culture on hydrophobic tissue culture inserts or agarose -coated plates. The success of this procedure depends on the use of lo w-serum media to prevent myocyte-myocyte interaction and proliferation of any residual endothelial cells. Myocytes cultured in this manner r etain many of their structural characteristics, suggesting that mainte nance of their elongated irregular shape is not dependent on interacti on with extracellular matrix. They also exclude trypan blue, can be vi tally stained by the uptake and reduction of the tetrazolium dye MTT 4 ,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide], synthesize myosin and when returned to adhesive surfaces are capable of attachme nt and attendant dedifferentiation. Stability of the myocytes in suspe nsion permits their use in co-culture experiments; specifically, myocy tes separated from endothelial cells by the hydrophobic membrane of th e tissue culture insert stimulated proliferation of the latter cells, suggesting this to be a useful system for studying myocyte-endothelial cell interaction. (C) 1996 Academic Press Limited