Abstract:

Objective To study the impact of nonmyocytes conditioned media(NMCM) on the expression of α-and β-myosin heavy chain(MHC) mRNA of myocytes.Methods One to three-day-old SD rats were used.Cells were separated to myocytes and nonmyocytes(NMC) and the suspension of NMC was used as nonmyocyte conditioned media(NMCM).After 96 hours' culture,the myocytes were divided into 8 groups: group M: MC+new media;group C: MC+70% new media+30% NMCM;group L: MC+new media +Losartan(10^-6mol/L);group CL: MC+70% new media +30% NMCM+Losartan;group P: MC+ new media+ PD123319(10^-6mol/L);group CP: MC+ 70% new media +30% NMCM +PD123319;group LP: MC+new media+Losartan+PD123319;group CLP: MC+ 70% new media+30%NMCM+ Losartan+ PD123319.After 24 hours treatment,The expression of α-and β-myosin heavy chain(MHC) mRNA of myocytes were measured.Results The expression of α-MHC were lower in group C and CP than that in other groups.Losartan can inhibit the changing from α-to β-myosin heavy chain(MHC) mRNA.Conclusion NMCM can cause α-MHC changing to β-MHC.The changes could be inhibited by Losartan.

Key words: myocyte, nonmyocyte, angiotensin, myosin heavy chain