CARDIAC MYOCYTES AND FIBROBLASTS CONTAIN FUNCTIONAL ESTROGEN-RECEPTORS

Gender-based differences found in cardiovascular diseases raise the po ssibility that estrogen may have direct effects on cardiac tissue, The refore we investigated whether cardiac myocytes and fibroblasts expres s functional estrogen receptors, Immunofluorescence demonstrated estro gen receptor protein expression in both female and male rat cardiac my ocytes and fibroblasts, Nuclear translocation of the estrogen receptor protein was observed after stimulation of cardiomyocytes with 17 beta -estradiol (E-2). Cells transfected with an estrogen-responsive report er plasmid showed that treatment with E-2 induced a significant increa se in reporter activity, Furthermore, E-2 induced a significant increa se in expression of the estrogen receptors alpha and beta, progesteron e receptor and connexin 43 in cardiac myocytes, Cardiac myocytes and f ibroblasts contain functional estrogen receptors and estrogen regulate s expression of specific cardiac genes, These data suggest that gender -based differences in cardiac diseases may in part be due to direct ef fects of estrogen on the heart, (C) 1997 Federation of European Bioche mical Societies.