Effects of oestrogen and Cimicifuga racemosa on the cardiac noradrenaline pathway of ovariectomized rats

The aim of this study was to investigate the effects of oestrogen and Cimicifuga racemosa on the stellate ganglion, cardiac noradrenaline (NA) pathway and Ca2+-calmodulin-dependent protein kinase II (CaMK II). Forty adult female Sprague-Dawley rats were randomly divided into the following four groups: sham operated (SHAM); ovariectomized (OVX); ovariectomized with oestrogen treatment (E2); and ovariectomized with C. racemosa treatment (iCR). After 4weeks of treatment, the NA content was determined by high-performance liquid chromatography, and dopamine beta-hydroxylase (DBH) and noradrenaline transporter (NET) expression were detected by immunohistochemistry. Western blotting was used to determine NET, beta(1)-adrenergic receptor (beta(1)-AR) and CaMKII expression. Compared with the SHAM group, body weights, DBH and NET expression in the right stellate ganglia, and NET, beta(1)-AR and CaMK II expression in the left ventricles of the OVX group were increased, whereas left ventricular NA content was decreased; DBH and NET expression in the left stellate ganglion was not significantly different. The indexes of the E2 group were similar to those of the SHAM group. Moreover, in the iCR group, DBH, NET, beta(1)-AR and CaMK II expression was decreased; NET expression and NA content of the left ventricle remained unchanged. Our conclusions are as follows. First, the right stellate ganglion, but not the left, may be associated with decreased left ventricular NA content in OVX rats. Second, oestrogen increases the left ventricular NA content and adjusts the expression of DBH and NET in the right stellate ganglion and restores beta(1)-AR and CaMK II protein expression to normal levels. Third, C. racemosa does not affect left ventricular NA, but decreases the protein expression of beta(1)-AR and CaMK II.National Nature Science Foundation of China [81270666]SCI(E)ARTICLE8974-98410