Estrogen is known to have cardio protective effects in women. However, there are contradictory data about the cardiovascular effects of estrogen in men in the literature. The aim of this study is to investigate the effects of castration and estrogen treatment after castration on the heart tissues of male rats by immunohistochemically detecting various molecules (growth factors and receptors, chemokine’s and sex hormone receptors) that play a role in cardiovascular diseases. For this purpose, three experimental groups consisting of 21 male rats were formed in the study: control (C), castrated (M -) and post - castration 17 - beta estradiol (E2) treatment (MX) groups. The heart tissues obtained from all groups stained immunohistochemically with primer antibodies for transforming growth factor - β1 (TGF β1), transforming growth factor - β receptor I (TGF βRI), transforming growth factor - β receptor II (TGFβRII), platelet derived growth factor (PDGF), platelet derived growth factor receptor - α (PDGFR - α), platelet derived growth factor receptor - β (PDGFR - β), insulin - like growth factor - I (IGF - I), insulin - like growth factor - I receptor (IGF - IR), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), endothelial Nitric Oxide Synthetase (eNOS), endothelia - I (ET - I), estrogen receptors (ER - α, ER - β) and Androgen Receptor (AR). The results of the study showed that E2 treatment decreased the expressions of PDGF, PDGFR - β, IGF - I, bFGF and AR, and increased the expressions of TGFβRII, eNOS and ER - α. In conclusion, present study proposes a protective role for estrogens in male cardiovascular system and reveals possible molecular mechanisms for this role.