Effects of the aqueous extract of Schizandra chinensis fruit on ethanol withdrawal-induced anxiety in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>We previously demonstrated that the aqueous extract of the Schizandra chinensis fruit (AESC) ameliorated Cd-induced depletion of monoamine neurotransmitters in the brain through antioxidant activity. In the present study, we investigated the effect of AESC on anxiety-like behavior and the levels of norepinephrine and 3-methoxy-4-hydroxy-phenylglycol (a metabolite of norepinephrine) in different brain regions during ethanol withdrawal in rats.</p><p><b>METHODS</b>Male Sprague-Dawley rats were treated with 3 g/kg of ethanol (20%, w/v) or saline by daily intraperitoneal injection for 28 days followed by three days of withdrawal. During withdrawal, rats were given AESC (100 mg × kg(-1)× d(-1) or 300 mg × kg(-1)× d(-1), P.O.) once a day for three days. Thirty minutes after the final dose of AESC, the anxiogenic response was evaluated using an elevated plus maze, and the plasma corticosterone levels were examined by radioimmunoassay. Meanwhile, the concentrations of norepinephrine and 3-methoxy-4-hydroxy-phenylglycol in the hypothalamic paraventricular nucleus and hippocampus were also measured by high performance liquid chromatography.</p><p><b>RESULTS</b>Rats undergoing ethanol withdrawal exhibited substantial anxiety-like behavior, which was characterized by both the decrease in time spent in the open arms of the elevated plus maze and the increased level of corticosterone secretion, which were greatly attenuated by doses of AESC in a dose-dependent manner. The high performance liquid chromatography analysis revealed that ethanol withdrawal significantly increased norepinephrine and 3-methoxy-4-hydroxy-phenylglycol levels in the hypothalamic paraventricular nucleus, while not significantly altering them in the hippocampus. Similar to the results from the elevated plus maze test, the AESC significantly inhibited the elevation of norepinephrine and its metabolite in the hypothalamic paraventricular nucleus in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>These results suggest that AESC attenuates anxiety-like behavior induced by ethanol withdrawal through modulation of the hypothalamic norepinephrine system in the brain.</p>

Evidence for a major role of Mg~(2+) in bFGF-mediated angiogenesis / 中国药理学通报

Aim The mechanism of basic fibroblast growth factor(bFGF)in mediating increase of intracellular free magnesium ([Mg2+]i) in human umbilical vein endothelial cells (HUVECs), and the relationship between Mg2+and angiogenesis were investigated in this study.Methods The change of[Mg2+]i in HUVECs were quantitatively detected in intracellular cation measurement system via loaded with the fluorescent magnesium indicator mag-fura-2. Endothelial cells were primarily acquired by infusion of collagen enzyme solutioninto the lumens of human umbilical veins and cultured in M199 with 0.2 fetal bovine serum. The role of bFGF in angiogenesis was observed in presence of 0,1 mmol?L-1 or 2 mmol?L-1 of extracellular Mg2+.Results bFGF dose-dependently increased [Mg2+]i, and there was not any significant difference among the groups of 0,1 mmol?L-1and 2 mmol?L-1 of extracellular Mg2+;similar results were obtained in groups done with Na+ and Ca2+. Pretreatment with bFGF receptor-2 (KDR) inhibitor (SU1498) blocked the increase of [Mg2+]i induced by bFGF.Unlike in the group of 0 mmol?L-1extracellular Mg2+,the apparent angiogeneses were observed in the groups of 1 mmol?L-1 and 2 mmol?L-1 extracellular Mg2+ in the presence of bFGF.bFGF-induced angiogenesis was significantly blocked with SU1498 in the presence of 1 mmol?L-1 extracelluar Mg2+.Conclusions These results suggest that the increase of [Mg2+]i by bFGF come from intracellular Mg2+ pools mediated by KDR-dependent signaling pathways,thereby resulting in the bFGF-induced angiogenesis.