A contribution to a new test method for dandruff-inhibiting and “keratolytic” action of drugs

Summary Free cholesterol in lipids from the scalp and hair is predominantly a constituent of epidermal lipids. Therefore, a reduction in cholesterol content induced by a drug indicates a reduction in cell turnover in the epidermis. As, according to the literature, increased cell turnover in the epidermis results in formation of dandruff, a reduction in the proportion of cholesterol should indicate inhibition of the formation of dandruff. Conversely, an increase in free cholesterol should generally indicate a keratolytic effect. So unequivocal an interpretation has not so far been possible in persons with dandruff, as it was not known whether free cholesterol was increased or decreased. In addition, this interpretation was not possible after use of antimicrobial substances, as in vitro investigations had failed to exclude microbial esterification of cholesterol on the scalp. The present investigation has shown that correlation of free cholesterol level with cell turnover is permissible in patients with dandruff, even if antimicrobial drugs are being tested.     

Antinociceptive action of quipazine: Relation to central serotonergic receptor stimulation

Quipazine, a serotonin receptor stimulant, inhibited the response of rats to painful stimuli in two methods currently used to measure antinociception in these animals: the hot plate and tail compression test. The antinociceptive action was observed with doses ranging from 5 to 20 mg/kg i.p. according to the test situation.The effect was significantly antagonized by a pretreatment with methergoline, a potent serotonin antagonist. An electrolytic lesion placed in the nucleus raphe medianus, which produced a marked decrease of serotonin in the forebrain did not, or only slightly, affected the effect of quipazine, depending on the method used to measure antinociception.It is suggested that quipazine can produce antinociceptive action in rats by interacting with a serotonergic mechanism. The action appears to be due mainly to a direct action on postsynaptic serotonin receptors, although a presynaptic component can also contribute to the effect of quipazine.Visiting scientist from Clinica Neurologica, UniversitàVisiting scientist from Clinica Neurologica, Università     

Norepinephrine regulation of growth hormone release from goldfish pituitary cells. II. Intracellular sites of action

Previous results suggest that norepinephrine decreases growth hormone (GH) release in goldfish by means of alpha-2 adrenoceptor activation. The intracellular mechanisms by which norepinephrine inhibits GH release were examined in the present study using dispersed goldfish pituitary cells. In 2-h static incubation experiments, norepinephrine and the alpha-2 agonist clonidine decreased basal GH release and the GH responses to stimulation by the dopamine D1 agonist SKF38393 and two native gonadotropin-releasing hormones (GnRH). Norepinephrine also reduced GH responses to the adenylate cyclase activator forskolin, two protein kinase C (PKC) activators (phorbol ester and synthetic diacylglycerol), and two Ca2+ ionophores (ionomycin and A23187). Similarly, norepinephrine applied as a 1-h pulse in cell column perifusion experiments reduced basal GH release and abolished the GH response to a 5-min pulse of arachidonic acid. In goldfish, D1-stimulated GH release is mediated by AC-, arachidonic acid-and Ca2+-dependent pathways, whereas GnRH action is coupled to PKC-and Ca2+-dependent mechanisms. These results suggest that norepinephrine activation of alpha-2 receptors inhibits ligand-induced GH secretion by actions subsequent to activation of these second messenger cascades. To further characterize norepinephrine mechanisms of action on unstimulated hormone release, the ability of norepinephrine and an alpha-2 agonist to affect activation of two second messenger cascades under basal conditions was also investigated. Static incubation with clonidine reduced cAMP production in a time-and dose-dependent manner, suggesting that norepinephrine inhibitory action can also be expressed at the level of cAMP production. Resting intracellular free calcium levels in single, identified goldfish somatotropes was unaffected by norepinephrine. However, the inhibitory effects of norepinephrine on basal GH secretion was not observed in the presence of a voltage-sensitive Ca2+ channel agonist. Whether these channels are targets for norepinephrine action on unstimulated GH release requires further investigation.     

板蓝根醇沉物的药理作用

目的：观察板蓝根醇沉物与板蓝根颗粒剂的差异。方法：对比研究板蓝根醇沉物与板蓝根颗粒剂前浸膏的药理作用。结果：板蓝根醇沉物的热解、抗炎及抗茵作用与同剂量板蓝根颗粒剂前浸膏相同，其靛蓝含量高于板蓝根颗粒剂前浸膏。结论：板蓝根醇沉物有明显的解热、抗炎作用，板蓝根制剂传统制备工艺有待改进。     

川芎嗪及其衍生物对羟自由基的清除作用

目的:探讨川芎嗪及其衍生物对羟自由基的清除作用。方法:应用Fenton反应检测并计算50％羟自由基被清除时的药物浓度(EC_(50))。结果:结果显示对羟自由基均有明显清除作用,且呈剂量依赖关系。川芎嗪及其衍生物与苯甲酸和甘露醇的清除作用差异有极显著性(P<0.01),而相互间作用无明显差异(P>0.05)。结论:川芎嗪及其衍生物对羟自由基有明显的清除作用。     

糖尿病对大鼠坐骨神经动作电位潜伏期影响的观察

目的：观察糖尿病对大鼠坐骨神经动作电位潜伏期的影响。方法：剥离大鼠坐骨神经,利用BL-310生物信号处理系统测量其动作电住的潜伏期。结果：糖尿病大鼠坐骨神经动作电位潜伏期约为0．92ms，比正常大鼠动作电位潜伏期延长。     

海地瓜中多糖的提取和药理作用研究

目的 :研究海地瓜中多糖的提取方法。方法 :分别用酶法和碱法消化海地瓜药材提取多糖 ,并对提取的多糖做小鼠游泳试验。结果 :实验组均优于对照组 ,并具有显著性差异 (P <0 .0 1) ,酶法提取多糖组和碱法提取多糖组也存在显著性差异 (P <0 .0 5 )。结论 :酶法提取的多糖药理作用优于碱法提取的多糖     

益母草的化学、药理和临床研究进展

查阅近20年有关文献，对益母草的化学成分、药理作用、临床应用研究进展进行综述。益母草主要含有生物碱类、黄酮类、二萜类、脂肪酸类、挥发油类等化合物；药理作用研究证明其具有调经止血、保护心肌缺血再灌注损伤、抗血小板聚集、降低血液黏度等作用；在临床上常用来治疗流产后出血、冠心病、心肌缺血、高黏血症、痛经等疾病。益母草具有广泛的药理活性，对其药效学物质基础进行深入研究和开发，将具有重要意义。     

大豆苷元抗心律失常作用的研究

目的 :研究大豆苷元抗心律失常作用。方法 :常规抗心律失常方法。结果 :大豆苷元 (3.0,5.0mg·kg^-1)对氯仿诱发的小鼠室颤有明显的预防作用 ,大豆苷元 (0.8,1.0mg·kg^-1)对乌头碱诱发的大鼠心律失常有明显的治疗效果。大豆苷元 (0.2,0.3mg·kg^-1)还能对抗肾上腺素诱发的家兔心律失常 ,大豆苷元 (0.03% ,0.05%)能明显降低蟾蜍离体坐骨神经动作电位振幅。大豆苷元 (0.8,1.0mg·kg^-1)对氯化钙诱发的大鼠室颤具有预防作用 ,且能明显的降低大鼠的死亡率。以上作用具有明显的剂量依赖性。结论 :大豆苷元有明显的抗心律失常作用。其抗心律失常作用可能与其抑制Na⁺内流或Ca²⁺ 内流及与阻断-β 肾上腺素受体有关。     

防治SARS中药的筛选

SARS在世界范围内流行 ,在紧急阶段 ,由于临床处治方案颇有争议 ,迅速的筛选出有效的中成药供临床急用尤为重要和迫切。利用 9个药理筛选模型交叉验证的方法 ,综合评价了 30个中成药的有效性。 19个药物作为有效的药物筛选出来 ,其中 8个最有效作为控制SARS不同阶段症状的药物由全国防治非典指挥部科技攻关组在 2003年5月22日对全国进行发布。本文就筛选的策略 ,顶层设计和主要研究思路做一介绍 ,具体试验结果将陆续发表。