用金鱼或鲫鱼做胰岛素休克实验

用金鱼或鲫鱼做胰岛素休克实验胰岛素休克（惊厥）实验是为了使学生了解胰岛素调节血糖水平的机能。目前通常采用的方法是给小白鼠腹腔注射胰岛素进行实验观察。若改用金鱼或鲫鱼作为实验动物进行胰岛素休克实验既简便、易行，又具有趣味性。方法如下：材料活的金鱼或鲫鱼...     

“解剖鲫鱼”实验操作考试探索

考试是教学工作的一个环节,是完成教学任务的一种手段。实验课是否可以进行考试?实验课考试效果如何?我就这些问题进行了探索。“解剖鲫鱼”是初二动物学的一个实验。该实验是在讲授教材内容“鲫鱼生活习性、外部形态和内部结构”以后开设的,要求学生认识鲫鱼的形态结构,学会解剖鲫鱼的技能。实验前,我先播放了《解剖鲫鱼》的电视录像片。实验开始时,又向学生说明实验目的和要求,解剖仪器名称及正确使用的方法,让学生在观察鲫鱼的外     

动物组织中转氨基作用的比较研究 Ⅱ.肝组织中甘氨酸与组氨酸对α-酮戊二酸的转氨基作用

前文的实验曾经阐明大白鼠与其他四种脊椎动物(家鸽、乌龟、蟾蜍和鲫鱼)不同,在肝匀浆中甘氨酸不能与α-酮戊二酸进行转氨基作用。该文实验结果也表示,鼠肝匀浆     

介绍一种观察鲫鱼呼吸的实验方法

初中《生物》课本“观察和解剖鲫鱼”一节课中,安排有观察鲫鱼呼吸的实验内容。笔者通过几年来的教学实践,摸索出一种实验方法,效果很好。现介绍如下：1材料准备实验前先将红色粉笔研成粉末,加水搅拌,混合均匀。2实验方法用滴管吸取上述液体,垂直插入水中。将管口接近于鲫鱼口的附近。轻轻挤捏橡胶囊,使红粉笔液体滴到鲫鱼口周围水中。此时,我们就会观察到鲫鱼口张开,红色液体被吸入水中。而当鳃盖张开的时候,红色液体又从鳃盖后的鳃孔排到水中。通过上述实验,学生可以直观地观察到水流由口进人再从鳃孔排出。对理解鲫鱼的呼吸很…     

解剖鲫鱼可用水维持其心率

在初中动物学解剖鲫鱼实验中,为便于观察鲫鱼心房和心室的颜色区别,可用在鱼鳃上滴自来水的方法保证实验顺利完成。具体疗法是:     

剪掉鳍的鲫鱼运动现象的观察

在“鲫鱼”一节的小实验中提到,剪掉胸鳍和腹鳍的鲫鱼及剪掉尾鳍的鲫鱼,与保留全部鳍的鲫鱼对比,它们的游泳姿态和速度有什么不同？对这一小实验,我们不仅按课本上的要求进行了操作,而且还对这个实验进行了改进,做了较深入的研究和观察。1剪掉不同奇鳍的情况1．1只剪去背鳍：鲫鱼能侧立水中;运动时速度和方向基本同于正常鱼,只是身体略微有点摆动。1．2只剪去臀鳍：鲫鱼的平衡和运动情况与正常鱼无明显差别。1．3只剪去尾鳍：鲫鱼能侧立水中,尾部明显上翘;运动时,速度明显减慢,尾部摆动幅度较大,转弯不灵活。2剪掉不同偶鳍的情…     

胰岛素对去甲肾上腺素的心脏肌力效应的影响

在离体灌流豚鼠心脏的实验中已证实胰岛素有正性肌力作用。在人和实验动物上,大剂量儿茶酚胺引起心肌病理性变化及心功能损害,胰岛素可保护心肌免受儿茶酚胺引起的损害,在β受体阻断剂的作用下,胰岛素的正性肌力作用明显增强。胰岛素缺乏(糖尿病)时,心脏对儿茶酚胺的敏感性显著提高。     

胰岛素和胰高血糖素

高中生物必修课本第一册85页讲胰岛素的作用,第86页讲胰岛素和胰高血糖素的相互作用--拮抗作用;选修课本第12页讲胰岛素和胰高血糖素在血糖平衡调节中的作用.我认为教材中多处内容不清楚,教师在处理教材时容易产生疑问.现说明如下:……     

用局部麻醉法观察鱼鳍的作用

观察鱼鳍作用的演示实验 ,笔者采用对鱼体的鳍进行局部麻醉的方法 ,使鱼体局部神经传导阻滞 ,被麻醉的鳍在短时间内停止摆动 ,观察鱼鳍的作用效果很好。1　材料用具　活鲫鱼 (或泥鳅 ) ,盛有 60 %～ 70 %水的容器 ,注射器 (5 m L以下 ) ,针头 ,盐酸利多卡因 5 m L、10 0 mg1支 (医用麻醉药 ) ,解剖盘 ,纱布 ,细铁丝 1根。2　方法步骤　 1)把活鲫鱼 (或泥鳅 )放入盛有 60 %～70 %水的容器中。仔细观察鲫鱼 (或泥鳅 )的胸鳍、腹鳍、背鳍、臀鳍和尾鳍的摆动与身体运动形式。然后用细铁丝分别触碰各鳍 ,观察鲫鱼 (或泥鳅 )的反应状态。2 )把要…     

机械生长因子E肽的功能及研究展望

机械生长因子(MGF)E肽是胰岛素样生长因子Ⅰ(IGF-Ⅰ)基因剪接后的一段长40个氨基酸残基的延伸肽,其编码基因由IGF-Ⅰ基因的外显子5、6及部分外显子4组成。近年来的实验证明,MGFE肽能独立发挥促进肌肉肥大、修复肌肉损伤、保护神经元、提高心脏功能等多种重要的生理作用,有望对肌肉萎缩、肌营养不良、神经退行性疾病及大脑局部缺血等相关病症的新型药物开发产生重大推动,引起了国内外学者的广泛关注。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism