肉桂油对胰岛素抵抗小鼠糖脂代谢的影响

目的:研究肉桂油对胰岛素抵抗小鼠糖脂代谢的影响,探讨其作用机制.方法:采用高脂饲料喂养建立小鼠胰岛素抵抗模型,经肉桂油治疗后测定口服糖耐量及胰岛素耐受,观察体质量、血糖、血清胰岛素、甘油三酯、总胆固醇、瘦素、抵抗素、脂联素的变化.结果:肉桂油能降低胰岛素抵抗小鼠的体质量(30.3±3.6vs34.6±3.1,P<0.05)、血糖(7.6±2.2vs9.2±1.3,P<0.05)、血清胰岛素(1.3±0.1vs1.7±0.2,P<0.05)、甘油三酯(70.1±10.9vs65.4±19.5,P<0.05)、总胆固醇(93.2±13.8vs102.3±21.5,P<0.05)、瘦素、抵抗素水平,同时改善口服糖耐量,降低胰岛素抵抗.结论:肉桂油能有效改善胰岛素抵抗小鼠糖脂代谢,其作用与降低血清瘦素、抵抗素水平,增加胰岛素敏感性有关.     

Age-related changes in mitochondrial respiration and oxidative damage in the cerebral cortex of the Fischer 344 rat

This study probed possible age-related changes in mitochondrial bioenergetics in naïve Fischer 344 rats. Synaptic and extrasynaptic mitochondria were isolated from the cortex of one hemisphere of young (3-5 months), middle (12-14 months), or aged (22-24 months) rats. Respiration parameters were obtained using a Clarke-type electrode. Aged rats displayed no significant alterations in respiration, indicating mitochondria must be more resilient to the aging process than previously thought. Synaptic mitochondria displayed lower respiration capacities than the extrasynaptic fraction. Aged F344 rats appear capable of normal electron transport chain function without declines in ability to produce ATP. Markers of cortical oxidative damage (3-nitrotyrosine [3-NT], 4-hydroxynonenal [4-HNE], and protein carbonyls [PC]) were collected from the post-mitochondrial supernatant (PMS) from the contralateral hemisphere, and from mitochondrial samples following respiration analysis. Age-related increases in PC and 3-NT levels were found in synaptic mitochondria, whereas significant extrasynaptic elevations were only found in middle aged rats. These findings support an age-related increase in oxidative damage in the cortex, while proposing the two fractions of mitochondria are differentially affected by the aging process. Levels of oxidative damage that accumulates in the cortex with age does not appear to significantly impair cortical mitochondrial respiration of F344 rats.     

Mismatch negativity (MMN), the deviance-elicited auditory deflection, explained

The current review constitutes the first comprehensive look at the possibility that the mismatch negativity (MMN, the deflection of the auditory ERP/ERF elicited by stimulus change) might be generated by so-called fresh-afferent neuronal activity. This possibility has been repeatedly ruled out for the past 30 years, with the prevailing theoretical accounts relying on a memory-based explanation instead. We propose that the MMN is, in essence, a latency- and amplitude-modulated expression of the auditory N1 response, generated by fresh-afferent activity of cortical neurons that are under nonuniform levels of adaptation.     

Rodent models for compulsive alcohol intake

Continued seeking and drinking of alcohol despite adverse legal, health, economic, and societal consequences is a central hallmark of human alcohol use disorders. This compulsive drive for alcohol, defined by resistance to adverse and deleterious consequences, represents a major challenge when attempting to treat alcoholism clinically. Thus, there has long been interest in developing pre-clinical rodent models for the compulsive drug use that characterizes drug addiction. Here, we review recent studies that have attempted to model compulsive aspects of alcohol and cocaine intake in rodents, and consider technical and conceptual issues that need to be addressed when trying to recapitulate compulsive aspects of human addiction. Aversion-resistant alcohol intake has been examined by pairing intake or seeking with the bitter tastant quinine or with footshock, and exciting recent work has used these models to identify neuroadaptations in the amygdala, cortex, and striatal regions that promote compulsive intake. Thus, rodent models do seem to reflect important aspects of compulsive drives that sustain human addiction, and will likely provide critical insights into the molecular and circuit underpinnings of aversion-resistant intake as well as novel therapeutic interventions for compulsive aspects of addiction.     

肉桂、桂枝薄层鉴别方法之改进初探

目的：对2005版《中华人民共和国药典》（一部）中肉桂、桂枝的薄层鉴别方法进行了改进。方法：采用冷浸法提取，用石油醚（60—90℃）．乙酸乙酯（17：3）上行展开，以香草醛浓硫酸溶液显色。结果：采用改进后的方法对肉桂、桂枝进行薄层色谱，斑点较多且清晰。结论：改进后的方法能够初步区分肉桂和桂枝。     

HPLC法测定厚朴饮片含量的质量比较

对外观差异较大、炮制品、不同产地等厚朴饮片进行含量测定和分析比较,为医院临床用药、药厂生产投料提供参考依据。按《中国约典》2005年版一部厚朴项下,用高效液相色谱法进行含量测定。厚朴饮片含量与外观性状、产地、炮制方法均有一定关系。     

桑白皮提取物对糖尿病大鼠坐骨神经传导速度及生化功能的影响

目的探讨桑白皮提取物对糖尿病大鼠坐骨神经传导速度及功能的影响。方法采用四氧嘧啶复制糖尿病(DM)大鼠模型。将大鼠随机分为正常组、模型组、桑白皮提取物(高、低剂量)组、弥可保对照组,灌胃给药,1次.d-1,用药2wk后,观察各组大鼠坐骨神经突触素的变化。同时测定大鼠坐骨神经运动传导速度、感觉传导速度及感觉潜伏期,并进行感觉神经检测的摇尾实验。结果桑白皮提取物可明显增加坐骨神经突触素的含量(P<0.01或P<0.05),改善和增加糖尿病大鼠坐骨神经的感觉及运动传导速度(P<0.01或P<0.05),缩短其感觉潜伏期(P<0.01或P<0.05)。结论桑白皮提取物对实验性糖尿病大鼠坐骨神经损害有一定的治疗作用。     

木蝴蝶树皮中黄芩苷和白杨素的HPLC分析

目的:建立测定小蝴蝶树皮中黄芩苷和白杨素的反相液相色谱法。方法:采用 Phenomenex ODS 3(250 mm×4.6 mm,5μm)色谱柱;流动相:乙睛-0.2%磷酸溶液,梯度洗脱[0～10 min,乙腈-0.2%磷酸溶液比例(25:75);10～25 min 乙腈-0.2%磷酸溶液比例由(25:75)→(60:40)],流速:1.0 mL·min~(-1);检测波长:268 nm;柱温:30℃。结果:黄芩苷、白杨素线性范围分别为0.03～7.55 mg(r=0.9999)和0.01～2.21 mg(r=0.9999);黄芩苷、白杨素的平均回收率(n=9)分别为96.8%和97.2%。结论:该方法简便、准确,重复性好,为木蝴蝶树皮的进一步研究和质量控制提供科学依据。     

安徽不同产地牡丹皮质量分析

目的分析安徽主要牡丹皮产地四年生的牡丹皮质量。方法根据2005版《中华人民共和国药典》，从含水量、总灰分含量、酸不溶性灰分含量、浸出物含量、丹皮酚含量，考察了牡丹皮的质量。结果所选牡丹皮的丹皮酚含量最高为1.77％，最低为0．98％。结论南陵产牡丹皮在所选牡丹皮中质量最好。     

Cortex Lycii Radicis extracts improve insulin resistance and lipid metabolism in obese‐diabetic rats

Here we evaluate the effects of ethanol and aqueous extracts from Cortex Lycii Radicis (CLR) on insulin resistance and lipid metabolism in obese‐diabetic rats, which were induced by high fat feeding for 3 weeks after injection with streptozotocin (STZ). Diabetic rats treated with ethanol or aqueous extracts of CLR at 15 and 30 g/kg dosage for 7 weeks, had decreased body weights, concentration of serum glucose, triglyceride (TG), total cholesterol (TC), and low‐density lipoprotein‐cholesterol (LDL‐C), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), while the insulin‐sensitivity index (ISI) improved significantly compared with the control group. In addition, high contents of tumor necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6) and low adiponectin level were observed in the control group and levels of TNF‐α and IL‐6 in CLR groups showed obvious differences with the control group. Histopathologic examination also showed degrees of hepatocyte edema although hepatocyte ballooning degeneration was lessened in all CLR groups. Overall, ethanol extract from CLR seemed to be more effective than aqueous extracts in improving insulin resistance, resulted in elevating insulin sensitivity, adjusting glucose and lipid metabolism, correcting cytokines levels and ameliorating liver function, especially protecting the liver against lipoid degeneration. Copyright © 2008 John Wiley & Sons, Ltd.