目的探讨选择性仅1受体激动剂盐酸米多君对体位性心动过速综合征（POTS）的治疗效果。方法本组55例，为2000年5月-2007年9月在北京大学第一医院就诊或住院的POTS患儿，其中男23例，女32例；年龄5—19岁，平均（12．3±3．1）岁，随机分为治疗组（应用盐酸米多君及口服补液盐治疗）22例和对照组（应用口服补液盐治疗）33例，对两组儿童进行临床研究及直立试验、基础直立倾斜试验（BHUT）或硝酸甘油激发直立倾斜试验（SNHUT）研究，比较治疗前后患者的好转率、HUT转阴率以及随访终点时的临床痊愈率和有效率。采用SPSS10．0软件进行统计。结果治疗3周和6周后治疗组的好转率均明显高于对照组（100．0％ vs 42．4％，P〈0．001；100．0％ vs 42．4％，X^2=19．352，P〈0．001），随访终点时治疗组的临床痊愈率明显高于对照组（77．3％ vs 27．3％，X^2=13．239，P〈0．001），有效率也明显高于对照组（100．0％ vs 36．4％，X^2=22．647，P〈0．001）。治疗3周后治疗组和对照组HUT转阴率相比差异无统计学意义（31．8％ vs 12．1％，P〉0．05）；治疗6周后治疗组的HUT转阴率明显高于对照组（81．0％ vs 48．5％，P〈0．05）。结论选择性α1受体激动剂盐酸米多君对POTS患儿的治疗有效。
Objective To explore the effect of L-arginine on hypoxic pulmonary vascular structural remodeling and its possible mechanisms.Methods Eighteen Wistar rats were randomly divided into three groups: the hypoxia group, the hypoxia with L-arginine group and the control group. Pulmonary artery mean pressure was evaluated with right cardiac catheterization. Pulmonary vascular structural changes were also observed. Plasma concentration of nitric oxide (NO) was measured via spectrophotometry, and endothelin-1 (ET-1) mRNA expression in pulmonary artery endothelial cells was detected using in situ hybridization.Results The pulmonary artery mean pressure was significantly high in hypoxic rats than in normal controls (20.33±2.18?mm?Hg vs 15.38±1.05?mm?Hg, P<0.05). Microstructural and ultrastructural analysis revealed the development of hypoxic pulmonary vascular structural remodeling in the hypoxic rats. Meanwhile, the plasma NO concentration was markedly lower in the hypoxic rats than in controls (P<0.05). The expression signals of ET-1 mRNA by pulmonary artery endothelial cells of hypoxic rats strengthened obviously. L-arginine ameliorated pulmonary hypertension (16.73±1.35?mm?Hg vs 20.33±2.18?mm?Hg, P<0.05) as well as pulmonary vascular structural remodeling in the hypoxic rats in association with an increase in plasma NO concentration (P<0.05) and inhibited ET-1 mRNA expression by the endothelial cells of pulmonary arteries.Conclusion L-arginine might play an important role in the regulation of hypoxic pulmonary vascular structural remodeling and hypoxic pulmonary hypertension. The mechanism is probably related to promoting NO production and, as a result, inhibiting ET-1 mRNA expression by pulmonary artery endothelial cells in hypoxic rats.
