Objectives To study the effects of oestrogen on the mitochondrial structure and function damage induced by furazolidone in neonatal rat cardiomyocytes.
Methods Neonatal rat cardiomyocytes (NRCMs) were prepared from 1 to 2 days old Sprague-Dawley rats, and were randomly divided into normal control group, furazolidone treated groups, and the group treated with oestrogen and furazolidone. The cardiac mitochondrial structure was observed under electron microscopy, and the mitochondrial function was assessed through detecting the mitochondrial membrane potential (MMP) level and enzyme activities of succinate dehydrogenase (SDH) and cytochrome c oxidase (COX). The mitochondrial stereological parameters including surface density (Sv), volume density (Vv) and specific surface (Rsv, surface-to-volume ratio) were further studied.
Results The MMP level and enzyme activities of SDH and COX were all significantly decreased in a dose-dependent manner when NRCMs were exposed to 6.25-100 μM furazolidone for 48h (P < 0.05). The pretreatment of oestrogen could significantly improve MMP level and enzyme activities of SDH and COX when NRCMs were exposed to 50 μM furazolidone (P < 0.05). Morphometric analysis showed significant mitochondrial swelling with fractured or dissolved cristae when the NRCMs were stimulated with furazolidone for 48h, and the mitochondrial morphological damage was significantly attenuated by the pretreatment of oestrogen. Stereological analysis of cardiomyocyte mitochondria further revealed notable increase in Vv, and significant decreases in Sv and Rsv in a dose-dependent manner when NRCMs were exposed to 6.25-100 μM furazolidone for 48h (P < 0.05). The pretreatment of oestrogen could significantly improve mitochondrial stereological parameters including Vv, Sv and Rsv when NRCMs were exposed to 50μM furazolidone (P < 0.05).
Conclusions Estrogen could attenuate cardiomyocyte mitochondrial injury induced by furazolidone.