Inhibition of bile salt-induced apoptosis by cyclic AMP involves serine/threonine phosphorylation of CD95

BACKGROUND AND AIMS: Cyclic AMP (cAMP) inhibits bile salt-induced hepatocyte apoptosis; the underlying mechanisms are unclear. METHODS: The effects of cAMP on taurolithocholate-3-sulfate-(TLCS)- or glycochenodesoxycholate (GCDC)-induced CD95 (Fas/APO-1) activation and apoptosis were studied in 24-hour cultured rat hepatocytes and in perfused rat liver. RESULTS: TLCS induced a rapid oxidative stress response, c-Jun-N-terminal kinase (JNK) and epidermal growth factor (EGF) receptor (EGF-R) activation, subsequent EGF-R/CD95 association and CD95 tyrosine phosphorylation, CD95 membrane targeting, death-inducing signal complex (DISC) formation and hepatocyte apoptosis. None of these responses was triggered by cAMP; however, cAMP induced H89-sensitive serine/threonine phosphorylation of CD95. Similar data were obtained with GCDC, another proapoptotic bile acid. cAMP did not prevent the TLCS-induced oxidative stress response, JNK activation and EGF-R/CD95 association, however abolished EGF-R activation and subsequent CD95 tyrosine phosphorylation, CD95 membrane trafficking, and DISC formation in a H89-sensitive way. Also in presence of TLCS, cAMP induced rapid Ser/Thr phosphorylation of CD95 within 10 min. The effects of cAMP on the various steps of CD95 activation were also found in the intact perfused rat liver. Evidence is given that a cAMP-induced Ser/Thr phosphorylation favors internalization of CD95. CONCLUSIONS: Inhibition of bile salt-induced apoptosis by cAMP involves both PKA-dependent Ser/Thr phosphorylation of the CD95 and inhibition of EGF-R activation, which results in an inhibition of CD95 tyrosine phosphorylation, CD95 membrane targeting, and DISC formation. CD95 regulation involves complex phosphorylations with CD95-tyrosine phosphorylation favoring CD95 membrane trafficking and DISC formation, whereas CD95 Ser/Thr phosphorylation inhibits these processes.     

薄层扫描法测定鸦胆子油中油酸的含量

目的：研究鸦胆子油中油酸的定量方法。方法：采用双波长薄层扫描法对油酸进行含量测定,λ为４００ｎｍ,λＲ＝为６５０ｎｍ。结果：平均回收率达９８．７％,ＲＳＤ为２．２％。结论：该方法为评价和控制鸦胆子的质量提供了依据。     

中药复方洁肤净洗剂中粉防己碱的含量测定

目的建立复方洁肤净洗剂中粉防己碱的含量测定方法。方法采用薄层扫描法,薄层板:硅胶G薄层板,展开剂:氯仿-甲苯-乙醇-浓氨水(10∶5∶2∶0.5),显色方法:稀碘化铋钾溶液显色。结果粉防己碱在1.0～4.0μg范围内呈现良好的线性关系。平均回收率为102.1%,RSD为1.0%。结论此方法准确、可靠,可用于复方洁肤净洗剂中粉防己碱的含量测定。     

重楼皂苷类成分分析方法的研究进展

重楼是目前临床常用传统中药,皂苷类成分是其主要有效成分,其在抗肿瘤、止血、止痛、抗菌、抗炎、抗氧化、提高免疫力等方面均有较好的治疗作用,在中医药界备受关注。通过查阅文献和相关资料,对近年来有关重楼及其制剂中皂苷类成分的含量测定方法进行归纳整理,并分析其各自的特点和优势,为重楼的深入研究提供依据,同时为其药材及制剂的质量评价提供参考。     

育英颗粒剂的质量标准研究

目的：为了控制育英颗粒剂的质量。方法：采薄层色谱法对其中的白芍、甘草和积壳进行了鉴别,并建立薄层扫描法对其中主药黄芪中的黄芪甲苷进行定量。结果：显示鉴别项下的阴性对照品无干扰,专属性强,含量测定黄芪甲苷在1－6μg间有良好的线性关系（r=0.9997),回收率98．32％,RSD为1．38％,结论：本质量标准可有效地控制育英颗粒剂的质量。     

薄层扫描法测定人体血液中牛磺酸的含量

目的：对人血中牛磺酸的含量测定研究,方法：用薄层扫描法,结果：方法简便、精密度高、重视性好,灵敏度可达40ng,平均回收率为98．97％,结论：适合大批量样品分析,可用作体内药代动力学研究中牛磺酸的检测。     

薄层扫描法测定脾胃健口服液中黄芪甲苷的含量

目的：建立脾胃健口服液的含量测定方法。方法：采用薄层扫描法测定其中黄芪甲苷的含量。结果：平均回收率为96．55％,RSD＝3．53％（n=5),结论：方法简便,结果准确,可用于该产品的质量控制。     

薄层扫描法测定藏药威隆风湿壮骨酒中异亮氨酸的含量

目的：建立藏药威隆风湿壮骨酒中异亮氨酸含量测定方法。方法：应用薄层扫描法硅胶G薄层板,展开剂为正醇-冰醋酸-水（3：1：1）,喷以1%茚三酮乙醇溶液,105℃加热至显色,测定波长为500nm。结果：异亮氨酸在0.908-4.54ug范围内线性关系良好,r=0.9999;平均回收率为99.08%,RSD=1.8%,(n=5);结论：本法简便,结果准确,稳定。     

薄层扫描法测定坤元通乳口服液中人参皂苷Re的含量

目的研究坤元通乳口服液的质量控制指标.方法采用薄层扫描法对人参中主要有效成分人参皂苷Re的含量进行了测定.结果该方法的线性范围为0.28～2.27 μg,平均回收率为96.90%,RSD为2.37%.结论方法可行,专属性强,重复性好,能有效地控制该制剂的质量.     

薄层扫描法测定抗感冒片中绿原酸的含量

目的：测定抗感冒中绿原酸的含量,方法：用乙醇提取并制成供试品,以薄层扫描法测定,λs＝333nm,λR=220nm,结果：平均回收率98．7％,RSD＝1．87％,三批样品中绿原酸的含量分别为2．455mg/片,2．368mg/片,2．262mg/片。结论：本法简便,准确,灵敏,可作为该制剂的质量控制方法。