Received 2001-12-25 Accepted 2002-03-27

*Corresponding author. Tel: +86-311-6064121-5560; E-mail: syho@hebmu.edu.cn

生理学报, Aug. 2002, 54 (4): 354~358

Acta Physiologica Sinica

研究论文

植物雌激素三羟异黄酮抑制麻醉大鼠颈动脉窦压力感受器反射

王义和1, 王 升2, 何瑞荣2,*

1武警医学院生理教研室, 天津 300162; 2河北医科大学基础医学研究所生理室, 石家庄 050017

摘 要: 采用隔离灌流麻醉雄性大鼠颈动脉窦技术, 观察了植物雌激素三羟异黄酮(genistein, GST)对颈动脉窦压力感受器反射的影响。其结果如下: (1)以GST (50 µmol/L)隔离灌流颈动脉窦区时, 压力感受器机能曲线向右上方移位, 曲线最大斜率(peak slope, PS)由0.36±0.01降至0.23±0.01 (P<0.001), 反射性血压下降幅度(reflex decrease, RD)由39.75±1.58 降至27.00±0.60 mmHg (P<0.001), 阈压(TP)和饱和压(SP)分别从65.63±2.10和192.23±3.90升至82.05±1.95 mmHg (P<0.001)和215.76±3.75 mmHg (P<0.001)。其中RD、PS和TP呈明显的剂量依赖性; (2)用Ca2+通道激动剂Bay K 8644 (500 nmol/L)预处理后, 能取消GST(50 µmol/L)对压力感受器反射的抑制作用; (3)预先灌流NO合酶阻断剂(L-NAME, 100 µmol/L), 不能阻断GST (50 µmol/L)对压力感受器反射的抑制效应。以上结果提示, GST可能通过阻断Ca2+通道途径而抑制大鼠颈动脉窦压力感受器反射, 并非由血管内皮细胞释放NO所致。

关键词: 三羟异黄酮; Bay K 8644; 压力感受器反射; 平均动脉压

学科分类号: Q463

Phytoestrogen genistein inhibits carotid sinus baroreflex

in anesthetized male rats

WANG Yi-He1, WANG Sheng2, HE Rui-Rong2,*

1Department of Physiology, Medical College of Chinese People's Armed Police Forces, Tianjin 300162; 2Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017

Abstract: The purpose of this study was to determine the effect of phytoestrogen genistein (GST) on carotid sinus baroreflex in 30 anesthetized male rats by perfusing the isolated carotid sinus in vivo. The results obtained are as follows. (1) By perfusion with GST (50 µmol/L), the functional curve of baroreflex was shifted to the right and upward, with a peak slope (PS) decrease from 0.36±0.01 to 0.23±0.01 (P<0.001) and a reflex decrease (RD) in mean arterial pressure from 39.75±1.58 to 27.00±0.60 mmHg (P<0.001), while the threshold pressure (TP) and saturation pressure (SP) were significantly increased from 65.63±2.1 to 82.05±1.95 mmHg (P<0.001) and from 192.23±3.90 to 215.76±3.75 mmHg (P<0.001), respectively. Among the functional parameters of carotid baroreflex, the changes in RD, PS and TP were dose-dependent. (2) Pretreatment with Bay K 8644 (500 nmol/L), an agonist of calcium channels, could completely abolish the inhibitory effect of GST on carotid baroreflex. (3) Preperfusion with an inhibitor of NO synthase, L-NAME (100 µmol/L), did not affect the inhibitory effect of GST. It is proposed that the inhibitory action of GST on carotid baroreflex may be mediated by the inhibition of Ca2+ channel of vascular smooth muscle, but not by NO release from endothelium.

Key words: genistein; Bay K 8644; baroreflex; mean arterial pressure