Isoprenaline-like effects of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine on mechanical,biochemical and electrophysiological parameters in the mammalian heart

Summary The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) mimicked the effects of isoprenaline on the force of contraction, the cAMP content and the slow Ca⁺⁺ inward current (I_si) in isolated guinea pig papillary muscles. The results support the hypothesis that phosphodiesterase inhibitors and -adrenoceptor agonists exert their positive inotropic effects by increasing I_si via the common mediator cAMP.Acknowledgment. This work was supported by the Deutsche Forschungsgemeinschaft.     

飞龙掌血水提物对异丙肾上腺素致大鼠心肌缺血的保护作用

通过用异丙肾上腺素造成的大鼠心肌缺血模型,观察飞龙掌血（Ｔｏｄｄａｌｉａａｓｉａｔｉｃａｌａｍ）水提物（飞龙一号,Ｆ０１）对心肌过度兴奋所致心肌缺血的保护作用。结果显示：Ｆ０１（５２５ｍｇ·ｋｇ１）能明显缓解心电图Ｔ波改变,其作用与维拉帕米及普萘洛尔相似,但对心率的影响与上述两药明显不同。表明Ｆ０１对心脏过度兴奋所致心肌缺血有保护作用,此作用可能与其抑制Ｃａ２＋转运导致的心肌细胞内Ｃａ２＋减少有关。     

流动注射化学发光法测定异丙基肾上腺素

采用流动注射技术,研究了酸性条件下高锰酸钾与异丙基肾上腺素的化学发光行为,对影响化学发光强度的诸因素进行了实验和探讨,建立了流动注射化学发光法测定异丙基肾上腺素的新方法.方法的检出限为6×10-9g/mL,线性范围为2.0×10-8～1 0×10-5g/mL对4.0×10-7g/mL异丙基肾上腺素进行11次平行测定,相对标准偏差为1 5%.方法用于测定盐酸异丙基肾上腺素的含量,结果与药典标准方法相一致.     

毛细管电泳法分离检测三种肾上腺素类化合物

采用毛细管电泳法对去甲肾上腺素、去氧肾上腺素和异丙肾上腺素三种肾上腺素类化合物进行分离检测.在电泳运行缓冲液为100mmol/L NaH2PO4(pH=5.2)中,当分离电压为22kV时,三种肾上腺素类化合物在12min内达到基线分离.在最优的条件下,各组分的峰面积与待测物浓度在0.02-50μg/mL范围内呈良好的线性关系,检测限均为0.01μg/mL.将该方法用于加标尿样中上述三种分析物的测定,回收率为94.89%-105.9%.     

流动注射化学发光检测药物制剂中异丙肾上腺素及机理研究

基于异丙肾上腺素(IP)对luminol-KIO4化学发光体系信号的增强作用,发展了一种流动注射化学发光灵敏检测异丙肾上腺素的新方法.对影响化学发光强度和重现性的参数进行了系统优化.在优化条件下,该方法对IP检测的线性范围为5.0×10-9~1.5×10-6 mol/L,检出限为5.8×10-10 mol/L.对5.0×10-7mol/L的IP溶液平行测定12次的相对标准偏差为1.7%,分析通量为130个/h.将该方法应用于药物制剂盐酸异丙肾上腺素注射液分析,加标回收率为99.2%~103.2%.利用化学发光光谱和紫外光谱对该化学发光反应的增强机理进行了探讨.     

Effects of receptor agonists on polyamine concentrations and spermidine/spermine N1-acetyltransferase activity in rat parotid gland

The polyamine putrescine might be formed via a degradation (catalyzed by spermidine/spermine N¹-acetyltransferase, SSAT) of the higher polyamines spermidine and spermine to putrescine. The involvement of different intracellular signal pathways in the regulation of putrescine formation was studied in explants and in cultured cells of rat parotid glands by using receptor agonists that activate separate second messenger systems, and measuring their effects on the concentrations of putrescine, spermidine and spermine and on the SSAT activity. The -adrenoceptor agonist isoprenaline, which is an activator of cAMP formation, increased the putrescine concentration and stimulated the SSAT activity. Pilocarpine, a drug that activates the muscarinic receptors and thereby enhances the phosphoinositide turnover, had no effect on either the polyamine concentrations or on the SSAT activity. Epidermal growth factor (EGF), which induces activation of a protein tyrosine kinase, had no effect on the polyamine concentrations or on the SSAT activity. The adenylate cyclase activator forskolin increased the glandular levels of putrescine. Taken together, these findings suggest that increases in putrescine concentration in cultured rat parotid gland cells are accompanied by accumulation of cAMP.     

盐酸异丙肾上腺素的电化学测定

将羧基化的多壁碳纳米管(MWCNT)修饰在裸玻碳电极表面,制得碳纳米管修饰电极,实验发现该电极对盐酸异丙肾上腺素有明显的电催化作用,峰电流显著增加,并对pH、底液、MWCNT修饰量、伏安测定方法进行选择以及对所选定方法的仪器参数进行优化.实验表明最佳条件为pH 6.0的tris-HCl缓冲溶液,MWCNT修饰量为14μL,采用方波脉冲伏安法,其振幅为0.055V.在最佳条件下,盐酸异丙肾上腺素浓度在4.0×10-5～1.2×10-4 mol/L范围内,其峰电流与浓度呈良好的线性关系,检测下限为1.12×10-7 mol/L,其峰电流的相对标准偏差(RSD)为0.49%.一些常用的离子如NO3-、Cl-、NH4+、K+、Na+对其无干扰.