Dietary intervention with vitamin D,calcium, and whey protein reduced fat mass and increased lean mass in rats

The aim of the current study was to determine the effects and the mechanisms of inclusion of dietary whey protein, high calcium, and high vitamin D intake with either a high-sucrose or high-fat base diets on body composition of rodents. Male Wistar rats were assigned to either no whey protein, suboptimal calcium (0.25%), and vitamin D (400 IU/kg) diet (LD), or a diet containing whey protein, high calcium (1.5%), and vitamin D (10 000 IU/kg) diet (HD), and either high-fat (40% of energy) or high-sucrose (60%) base diets for 13 weeks. Liver tissue homogenates were used to determine [¹⁴C]glucose and [¹⁴C]palmitate oxidation. mRNA expression of enzymes related to energy metabolism in liver, adipose, and muscle, as well as regulators of muscle mass and insulin receptor was assessed. The results demonstrated that there was reduced accumulation of body fat mass (P = .01) and greater lean mass (P = .03) for the HD- compared to LD-fed group regardless of the background diet. There were no consistent differences between the LD and HD groups across background diets in substrate oxidation and mRNA expression for enzymes measured that regulate energy metabolism, myostatin, or muscle vascular endothelial growth factor. However, there was an increase in insulin receptor mRNA expression in muscle in the HD compared to the LD groups. In conclusion, elevated whey protein, calcium, and vitamin D intake resulted in reduced accumulation of body fat mass and increased lean mass, with a commensurate increase in insulin receptor expression, regardless of the level of calories from fat or sucrose.     

吸烟、硝酸甘油对动脉粥样硬化家兔血管平滑肌细胞钙浓度的影响

目的研究吸烟、硝酸甘油对动脉粥样硬化血管平滑肌细胞胞内游离钙浓度([Ca2+]i)的影响,探讨吸烟对动脉粥样硬化形成及硝酸甘油的生物效应的作用。方法复制家兔动脉粥样硬化模型,分离血管平滑肌细胞。Fluo-3/AM负载细胞,应用流式细胞仪检测血管平滑肌细胞[Ca2+]i,激光扫描共聚焦显微系统测定单个血管平滑肌细胞内Ca2+的时空变化。结果各组动物主动脉壁均见到程度不同的动脉粥样硬化斑块形成。动脉粥样硬化家兔血管平滑肌细胞[Ca2+]i明显升高(48.45±5.31,与生理盐水对照组38.09±2.57比较,P<0.01);吸烟能增加动脉粥样硬化家兔血管平滑肌细胞[Ca2+]i(56.48±2.99,与单纯动脉粥样硬化组48.45±5.31比较,P<0.01);硝酸甘油则能明显降低动脉粥样硬化家兔血管平滑肌细胞[Ca2+]i(41.91±3.16,与单纯动脉粥样硬化组48.45±5.31比较,P<0.05);吸烟能明显抑制硝酸甘油降低血管平滑肌细胞[Ca2+]i的作用(47.99±5.10,与硝酸甘油组41.91±3.16比较,P<0.05)。结论吸烟能明显增加动脉粥样硬化血管平滑肌细胞[Ca2+]i,硝酸甘油则能明显降低动脉粥样硬化血管平滑肌细胞[Ca2+]i,吸烟能抑制硝酸甘油的生物学效应。     

牛奶及其制品与乳腺癌关系的研究进展

乳腺癌是西方女性最常见的肿瘤，我国女性乳腺癌患者也逐年上升。和所有的肿瘤一样，乳腺癌的病因复杂多样，其中包括饮食因素。众多考察乳腺癌的流行病学研究提及奶及其制品的影响，但没能得出一致的结论。著名的美国护士健康研究也没有发现奶和奶制品摄入与乳腺癌发生有明显关系。汇总观察这些流行病学资料发现，奶酪能微弱地增加患乳腺癌的危险。动物研究表明，现代牛奶中富含的雌激素和胰岛素样生长因子（IGF）-I有明显的促进二甲基苯并蒽（DMBA）诱导的大鼠乳腺肿瘤的生长。系统介绍流行病学研究和实验室研究的最新成果，同时讨论牛奶中存在的可能影响乳腺癌发生的诸多成分，其中起促进作用的有饱和脂肪、各类激素和污染物，起保护作用的有钙、维生素D和一些脂肪酸。     

人参皂苷Rg1抑制PGF_(2α)诱导心肌细胞肥大

目的观察人参皂苷Rg1(ginsenoside Rg1,Rg1)对前列腺素F2α(prostaglandin F2α,PGF2α)所致心肌肥大的影响。方法利用培养的新生大鼠心肌细胞,以细胞直径、蛋白含量?心房利钠因子(atrial natriuretic factor,ANF)mRNA的表达为心肌肥大标志,观察药物的抗心肌肥大效应。AN-FmRNA的表达用Real-time PCR检测;用Fura-2/AM负载的培养心肌细胞检测细胞内游离钙浓度([Ca2+]i);一氧化氮试剂盒测定细胞上清液中一氧化氮(nitric oxide,NO)代谢物的含量,以探讨Rg1可能的作用机制。结果PGF2α0.1μmol·L-1使心肌细胞直径明显增大,蛋白质含量明显增加,ANF mRNA的表达增强,并使[Ca2+]i明显升高。Rg115.6、31.2和62.4μmol·L-1使经PGF2α处理的心肌细胞的直径分别缩短18.4%、32.7%和43.8%;使心肌细胞蛋白含量分别减少8.2%、14.6%和17.7%;Rg1 62.4μmol·L-1还使ANF mRNA的表达降低;Rg1 15.6、31.2和62.4μmol·L-1呈剂量依赖地抑制PGF2α所致的[Ca2+]i升高;NO前体L-精氨酸(L-arg)1 mmol.L-1具有相似的作用。此外,NO合酶抑制剂L-NAME可取消L-arg的作用,并部分抑制Rg1的效应;Rg1还明显升高心肌细胞上清液NO代谢物的含量。结论Rg1可抑制PGF2α诱导的心肌细胞肥大,该作用可能与其促进心肌细胞NO的释放,降低由PGF2α所升高的心肌细胞[Ca2+]i有关。     

氨基酸鳌合钙联合骨化三醇治疗肾性骨病的临床观察

目的:探讨治疗继发性甲状旁腺功能亢进(SHPT)骨病的方法.方法:对48例长期血液透析的慢性肾功能衰竭患者分别给予骨化三醇及骨化三醇联合钙剂治疗,观察血清钙、磷、钙磷乘积、甲状旁腺激素(PTH)水平变化,并对两种治疗方法的结果进行比较.结果:两种治疗均可显著增加血清钙水平,降低血清磷水平,骨化三醇加钙剂治疗的疗效更为显著(P＜0.01).结论:钙荆加骨化三醇治疗SHPT骨病优于单用骨化三醇.     

Effects of the Chinese herb component phellopterin on the increase in cytosolic free calcium in PC12 cells

The present study investigated the effects of the Chinese Herb component, phellopterin on high K⁺ and glutamate‐induced extracellular calcium influx and caffeine or cyclopiazonic acid (CPA)‐induced calcium release from internal stores in attached PC12 cells. Attached cells were loaded with the calcium fluorescent indicator Fluo‐3/AM with the final concentration of 5 µM for 50 min at 37°C and cytosolic free Ca²⁺ measured as fluorescent intensity (FI) (excitation: 488 nm; emission: 535 nm). When PC12 cells were exposed to extracellular Ca²⁺([Ca²⁺]₀) 2.0 mM, the FI for resting [Ca²⁺]_i was 1,188±163, high K⁺ (75 mM) and glutamate (10 mM) induced an increase in [Ca²⁺]_i with peak values of 4,270±982 and 3,096±402, respectively. Phellopterin (0.1–100 µM) had no apparent effect on resting [Ca²⁺]_i, but inhibited high K⁺ and glutamate induced the increase in [Ca²⁺]_i in a dose‐dependent manner. When PC12 cells were exposed to Ca²⁺‐free solution, the FI for resting [Ca²⁺]_i was 804±77. Caffeine (40 mM) and CPA (30 µM) stimulated Ca²⁺ release from caffeine‐ryanodine and inositol 1,4,5‐tris‐phosphate (InsP₃₎‐sensitive internal calcium stores, inducing an increase in [Ca²⁺]_i to 2,938±362 and 1,816±291, respectively. Phellopterin (0.1–100 µmol/L) inhibited caffeine and CPA stimulated intracellular calcium release in a dose‐dependent manner. In summary, phellopterin, a novel component isolated from Changii radix, inhibited Ca²⁺ influx induced by stimulation of voltage‐gated and receptor‐dependent calcium channels with a greater inhibition of receptor‐dependent calcium channels. It also inhibited Ca²⁺ release from caffeine‐ryanodine and InsP₃‐sensitive internal stores, being more potent for caffeine stimulation. Phellopterin may be a promising candidate for the development of new classes of calcium antagonists. Drug Dev Res 68:79–83, 2007. © 2007 Wiley‐Liss, Inc.     

反相离子对高效液相色谱法测定人血浆中羟苯磺酸

目的:建立测定羟苯磺酸血浆浓度的反相离子对高效液相色谱法,并用于临床药物动力学研究。方法:0.5 mL 血浆样品经乙腈沉淀蛋白处理后,以0.05 mol·L~(-1)磷酸二氢钾缓冲液(pH 3.0)-乙腈(87:13,v/v)为流动相(流动相中含0.1%四丁基氢氧化铵),Diamonsil C_(18)柱分离,检测波长为300 nm,流速为1.0 mL·min~(-1)。结果:测定血浆中羟苯磺酸方法的线性范围为0.364～36.4 mg·L~(-1),定量下限为0.364 mg·L~(-1)。日内、日间精密度(RSD)均小于8.7%,准确度(RE)在±4.5%以内。羟苯磺酸和内标对氨基苯甲酸的平均血浆样品处理回收率分别为74.8%和94.8%。结论:该方法选择性强,操作简单,适用于羟苯磺酸钙的临床药物动力学研究。     

5-氨基水杨酸果胶钙微丸的制备及粉体学性质与释药特征的考察

目的考察含有5-氨基水杨酸的果胶钙骨架微丸的制备过程的影响因素以及微丸的粉体学性质与释药特征。方法采用挤出滚圆法制备5-ASA果胶钙微丸,通过考察含钙量不同的果胶钙微丸以及处方中果胶钙含量不同的微丸的粉体学性质和释药曲线,从而确定制备微丸的最佳处方。将果胶钙微丸与普通微丸(不含果胶钙)和含质量分数为3%的崩解剂的微丸在pH7.4 PBS中的释药曲线进行比较,并比较果胶钙微丸在pH7.4 PBS、含果胶酶及含大鼠盲肠内容物的pH7.4 PBS中的释药曲线,同时结合SEM法分析释药机理,从而评价果胶钙在微丸中的作用。结果当果胶钙的含钙量为15 mg.g-1,处方中果胶钙的含量质量分数为20%时,微丸成球性较好,且5-ASA果胶钙微丸在1 h内即可释放完全,其释药速度明显快于5-ASA普通微丸和含质量分数为3%崩解剂的5-ASA微丸,而在大鼠盲肠内容物存在的条件下,5-ASA果胶钙微丸0.5 h内便释放完全。结论果胶钙在微丸中能加快药物的释放,且具备一定的酶降解性能,可用于制备难溶性药物微丸及难溶性药物结肠定位制剂包衣微丸的丸芯。     

反相高效液相色谱-质谱法测定人血浆中阿坎酸钙浓度

目的反相高效液相色谱-质谱法测定人血浆中阿坎酸钙浓度.方法采用API 3 000 LC-MS/MS液质联用系统.Phenomenex Gemini C18分析柱(50 mm×3.0 mm,3 μm),流动相为10 mmol·L-1乙酸铵-甲醇(95∶5,氨水调pH至7.4),流速为0.2 mL·min-1.样品用乙腈沉淀蛋白,离心,定量取上清液挥干,二氯甲烷洗后进样,按外标法定量.结果标准曲线在2～2 048 μg·L-1范围内有良好线性,最低定量限为2.0 μg·L-1,阿坎酸钙的保留时间为2.4 min,日内RSD＜4.0%,日间RSD＜11.6%,方法回收率为80%～104%,预处理回收率为83.6%～94.4%.结论本法具有快速简便、灵敏准确等特点,适用于阿坎酸钙血药浓度测定及药动学、生物利用度研究.     

兴奋性神经毒性中的钙稳态失调及其在退行性病变中的作用

兴奋性氨基酸受体的过度活化会导致神经元的兴奋性死亡,该过程与细胞内钙离子([Ca2+]i)稳态失调密切相关。谷氨酸兴奋毒性参与许多急慢性神经病变的发病及病程进展,提示Ca2+信号传导阻滞剂的应用可能在疾病的早期阶段就阻断病变进程,达到有效治疗。