树脂吸附对慢性肾功能衰竭维持性血液透析患者血清瘦素水平的影响

[目的]观察树脂吸附对慢肾衰维持性血液透析患者血清瘦素水平的影响.[方法]60例慢性肾功能衰竭维持性血液透析患者随机分为2组,树脂吸附组接受瘦素吸附器联合血液透析治疗,对照组接受血液透析治疗,记录治疗前后患者血细胞、白蛋白、球蛋白、肌酐、尿素氮和瘦素的改变,同时记录生命体征和不良反应.[结果]树脂吸附组患者血清瘦素从(15.6±13.3)ng/mL降至(9.7±10.1)ng/mL,差异有统计学意义(P＜0.05),平均单次清除率为39.9%;对照组患者血清瘦素从(16.1±12.1)ng/mL降至(15.6±11.2)ng/mL,差异无统计学意义(P＞0.05),单次清除率为0.3%.[结论]树脂吸附能安全有效地清除瘦素,而血液透析不能清除瘦素.     

单扫描示波极谱法测定麻黄碱

麻黄碱在强碱性条件下与Cu^2 形成络合物，并在滴汞电极上还原产生灵敏的极谱波。麻黄碱浓度为1～50μg／ml时，峰电流与浓度呈线性，检出限为0．5μg/ml，加标回收率为96．7％～113．8％，相对标准偏差RSD=3．22％～5.39％。本法可用于麻黄制剂中麻黄碱含量的测定。极谱波性质实验的结果表明该极谱波为络合吸附波。     

九分散中士的宁的胃肠吸收动力学研究

采用薄层扫描法测定了九分散灌胃后小鼠胃肠中士的宁的残留量,研究了九分散中士的宁的胃肠吸收动力学规律。结果表明,士的宁在小鼠体内的胃肠吸收符合一室药动学模型,并求出该制剂的主要动力学参数。     

吸收促进剂对三七总皂苷小肠吸收的影响

目的:研究三七总皂苷(panax notoginseng saponins,PNS)的小肠吸收动力学及吸收促进剂对PNS在小肠吸收速率和表观渗透系数的影响。方法:以紫外分光光度法、高效液相色谱法分别测定酚红和PNS的质量浓度,采用大鼠在体肠灌注实验考察吸收过程。结果:当药物质量浓度为40.084～400.840μg.mL-1时,大鼠小肠吸收速率常数和表观渗透系数无显著性差异(P>0.05);部分吸收促进剂能提高PNS在小肠的吸收水平,促吸收强弱顺序为:冰片>卡波姆>聚山梨酯-80,牛胆盐促吸收效果不明显,壳聚糖在一定程度上会延缓PNS的吸收。结论:PNS在大鼠小肠吸收较差,部分吸收促进剂对其吸收有一定的促进作用。     

Effect of α-methylnorepinephrine,an α2-adrenergic agonist,on jejunal absorption in neurally intact conscious dog

Although ₂-adrenergic agonists stimulate absorption in the mammalian small and large intestinein vitro, the possibility of central neural effects have confounded interpretation ofin vivo studies. Our aim was to assess the effects of intravenous administration of -methylnorepinephrine (MNE), and ₂-adrenergic agonist that does not cross the blood-brain barrier, on net jejunal absorption of water and electrolytes in the neurally intact, conscious dog. Absorption from a 30-cm proximal jejunal segment was studied using a triple-lumen perfusion technique in seven dogs. A warmed, isosmolar, balanced electrolyte solution containing [¹⁴C]polyethylene glycol was infused at 5 ml/min. Net jejunal fluxes of water and electrolytes were determined before, during, and after a 1.5-hr infusion of MNE (900 nmol/kg/hr). MNE increased net jejunal water absorption (from 12.9±1.8 to 22.5±1.5 l/cm/min,P<0.05). Peripheral ₂-adrenergic receptors mediate a net proabsorptive response in the neurally intact canine jejunumin vivo independent of direct central neural effects.Parts of this work were published as an abstract inGastroenterology (100:A689, 1991). Supported in part by the United States Surgical Corporation, a grant provided by Harry S. Tan, and USPHS NIH grant DK39337 (M.G.S.).     

Absorptive Clearance of Carbamazepine and Selected Metabolites in Rabbit Intestine

The intestinal permeability of carbamazepine, an antiepileptic drug, was examined as a function of intestinal site (duodenojejunum vs colon). A through-and-through in situ intestinal perfusion technique was adopted using the rabbit as an animal model. Coperfusion of the 10,11-epoxide and the 10,11-transdihydrodiol metabolites along with carbamazepine allowed for an examination of the effect of lipophilicity on intestinal permeability when molecular weight differences are negligible. Our results showed that carbamazepine is absorbed from rabbit duodenojejunum as well as the colon, which may explain the prolonged absorption behavior observed in humans. Also, the absorptive clearance of compounds having similar molecular weights is dependent not only on the lipophilicity but also on the extent of solvent drag during the course of the perfusion.     

基于“伴随标志物”在线控制技术的绞股蓝总皂苷纯化工艺及成分鉴定研究

基于"伴随标志物"紫外在线检测技术以绞股蓝总皂苷(GPS)为目标,优化绞股蓝中GPS的纯化工艺,采用UPLC-QTOF-MS技术对GPS进行定性。"伴随标志物"紫外在线检测研究表明,上样终点为流出液吸光度为原药液的1/2时,洗脱终点为洗脱流出液吸光度基本稳定。UPLC-QTOF-MS鉴定出GPS提取物中的16个皂苷,其中新皂苷3个。该研究优选出的纯化工艺简单、检测方便、易于在线测定、实时记录,能较好的运用到大生产或生产的自动化中。质谱定性鉴定结果表明,基于"伴随标志物"紫外在线检测技术能很好地保留药材中的主要药效成分,为过程控制和质量溯源提供了分析工具。     

Endocytosis by absorptive cells in the middle segment of the suckling rat small intestine

In neonatal suckling rats, the absorptive cells of the duodenum, jejunum and ileum endocytose maternal milk macromolecules, including antibodies from the lumen. To determine whether the absorptive cells from the middle segment of small intestine have an apical endocytic membrane system that is the same as that of the duodenum, jejunum or ileum, we applied horseradish peroxidase by intraluminal injection, and examined the absorptive cells using light and transmission electron microscopy. In the middle segment of the small intestine, the absorptive cells had an apical endocytic membrane system including apical coated pits, apical invaginations, coated vesicles, vesicles, tubules, early endosomes, late endosomes and a large homogeneous electron-dense lysosome at the supranuclear region. This would suggest that the endocytic membrane system in the absorptive cells from the middle segment of the small intestine is specialized for quick and active intracellular digestion. The apical endocytic membrane system of the absorptive cells varied according to the segment of the small intestine, and the absorptive cells made their transition gradually from jejunal type to middle type, and then from middle type to ileal type at the suckling stage. The jejunal and ileal type of absorptive cells increased with growth, in contrast to the middle type.     

药物口腔黏膜吸收机理的研究进展

口腔黏膜给药途径已成为目前药学研究领域的热点之一。笔者检索国内外文献,简要介绍口腔黏膜的屏障结构和药物吸收途径,进而对口腔黏膜的吸收机理进行系统整理和分析。最终归纳出扩散理论、pH分配学说、黏膜结构变化理论、酶抑制理论、生物黏附理论、解聚理论和新型载药体系等七大理论,同时指出目前存在的问题和研究方向。主要包括:进一步完善药物口腔黏膜吸收机理的理论,使其系统化;研究和开发新型安全低毒有效的吸收促进剂以及新型载药体系;根据不同的吸收机理,改进促透剂、黏附剂、酶抑制剂等辅料筛选方法,建立合理的处方设计和评价方法。