电刺激束缚小鼠应激诱发胃溃疡及其机制的初步探讨

用电刺激躯体束缚的口唇部建立应生胃溃疡模型，以阿尔新兰－ＭｇＣｌ２洗脱法测定胃壁粘液量，研究安定、苯巴比妥钠、可的松、酚妥拉明、异丙上腺素、阿托品和乙醇对溃疡发生的影响，结果表明，安定、苯巴比妥负伤 异丙肾上腺素显著抑制溃疡发生；阿托品和乙醉可明显使溃疡加剧；酚托拉明和可的松对溃疡没有影响，模型动物胃壁粘液量与对照组比较以及所有药物对模型动物胃壁粘液量却没有明显变化，提示，电刺激束缚应激胃溃疡的发     

Evidence for two populations of excitatory receptors for noradrenaline on arteriolar smooth muscle

We have recorded the responses of arteriolar smooth muscle cells to iontophoretically applied noradrenaline. Records of both muscle movement and muscle membrane potential were made. We found that two distinct types of response could be detected, depending on the position of the noradrenaline micropipette. One type of response consisted of a localised constriction near the noradrenaline source: this effect could be abolished by the alpha-antagonist phentolamine and was not associated with a change in arteriolar membrane potential. The other type of response was a depolarisation similar to the excitatory junction potentials (e.j.ps) produced by sumpathetic nerve stimulation. These observations suggest that there are two populations of receptors for noradrenaline on arterioles, and could explain the paradoxical failure of alpha-antagonists to block neuromuscular transmission at some sutonomic end organs such as the vas deferens, arteries and arterioles.     

几种神经递质对蟾蜍离体胃电和胃内压的影响

本实验用缝合电极和插入气囊法,观察几种神经递质和阻断剂对蟾蜍离体胃电和胃内压活动的影响,结果如下:Ach使胃内压升高,此效应为阿托品所阻断;Ach使胃电慢波振幅降低,频率加快,此效应不能被阿托品阻断。NE和Ad均使胃内压降低,胃电振幅降低,频率减慢,心得安不能阻断这一效应,心得宁对胃内压的阻断作用大于regitina,而对胃电的作用小于regitina。单独使用阿托品、心得安、心得宁和regitina均影响胃电和胃内压活功,说明胃壁内神经丛参与胃运动的调节。     

Genetic hypertension in rats is accompanied by a defect in renal prostaglandin catabolism.

Noradrenaline releases prostaglandins in the kidney, and in rats these augment rather than reduce vasoconstriction produced by the amine. Homogenates of kidneys of New Zealand rats inbred for hypertension exhibit lower prostaglandin inactivation by 15-hydroxydehydrogenase than controls. At the same time, augmentation of noradrenaline vasoconstriction by the released prostaglandin is exaggerated. This biochemical defect could be the inherited abnormality primarily responsible for the development of hypertension in these animals.     

家兔胃消化性运动及收缩波分类

对 21 只带有胃瘘管(重2.5克)的兔,用气球法记录胃运动;另5只兔装有十二指肠再返瘘管(重2.3克/对),以检测进食前后胃排空量的动态变化。结果表明:兔胃呈持续性运动,但有低潮期(持续几分到十几分钟),表现为紧张度低平,收缩波幅明显减小并偶有高波出现。胃收缩波型分三类:快节律波(即20秒节律波)、慢节律波和长周期紧张性收缩。进食后胃排空量增多,各类波特别是慢节律波中三种波的数量比例分别出现明显增大或减小,这提示在促进胃排空方面,几种波分别起着不同的作用。本文对兔胃运动波型的分类,不是完全按照传统标准——单纯根据形态,而是掺进了“功能”这一因素。     

乙酰胆碱对人胃粘膜上皮细胞和胃腺癌细胞内钠、磷浓度的影响

采用OlympusAu640生化分析仪,检测了乙酰胆碱作用后培养的人胃粘膜上皮细胞和胃腺癌细胞内钠和磷的含量,以探讨乙酰胆碱对人胃粘膜上皮细胞和胃腺癌细胞内钠、磷浓度的影响。结果发现:与正常胃粘膜上皮细胞比较,胃腺癌细胞内钠浓度偏高(P<0 001),而磷浓度降低(P<0 01)。在乙酰胆碱作用下,胃腺癌细胞内钠和磷浓度均升高(P<0 05);正常胃粘膜细胞仅有钠浓度升高(P<0 001),磷浓度无变化。阿托品能阻断乙酰胆碱对磷浓度的升高作用(P<0 05),但对钠浓度无影响。     

蟾蜍消化道肥大细胞的观察

采用3种不同的固定方法、2种甲苯胺蓝染色方法,对蟾蜍胃和小肠的肥大细胞(mast cells,MC)进行了研究.结果表明,蟾蜍胃和小肠中均有MC分布;MC呈长梭形、圆形、卵圆形、不规则形,主要存在于粘膜固有层或粘膜下层内,并且有围绕血管、腺泡分布的趋向;胃的固有层内MC少于粘膜下层,小肠固有层内MC多于粘膜下层;胃和小肠肌层中的MC都较少.3种固定方法中,用Carnoy液固定效果最好.在快速甲苯胺蓝染色法中,组织结构清晰可辨,MC易定位,呈紫红色;在常规甲苯胺蓝染色法中,MC不易定位,被染成蓝色.     

高压电火花在治理油层伤害中的应用

高电压在液体中突然放电,产生具有巨大能量的高压电火花强烈冲击波可以有效地破坏并清除岩石孔隙中的堵塞物,还能使岩层中裂缝增加,扩大油气流动通道;孔隙的扩张和收缩也使油气流速加快.用水和20号机油作实验,岩样经高压电火花作用后,其渗透率提高25.8％～436％,被堵塞的岩样的渗透率亦能恢复到堵塞前的42.6％～97.1％.     

Noradrenaline contracts arteries by activating voltage-dependent calcium channels

Noradrenaline (NA) regulates arterial smooth muscle tone and hence blood vessel diameter and blood flow. NA apparently increases tone by causing a calcium influx through the cell membrane. Two calcium influx pathways have been proposed: voltage-activated calcium channels and NA-activated calcium-permeable channels that are voltage-insensitive. Although voltage-activated calcium channels have been identified in arterial smooth muscle, voltage-insensitive calcium channels activated by NA have not. We show here that NA contractions of rabbit mesenteric arteries increase with depolarization. The increase parallels the elevation of open-state probability (P0) of single, voltage-dependent calcium channels. The action of noradrenaline can be explained by NA-activating voltage-dependent calcium channels, rather than by opening a second type of channel. We show directly that NA increases the open-state probability of single calcium channels. Thus, in the presence of NA, calcium entry through voltage-dependent calcium channels can regulate smooth muscle tone at physiological membrane potentials. These results may have relevance to pathophysiological conditions such as hypertension.     

豚鼠离体小肠电活动与机械收缩

以小肠电活动和环肌张力、纵肌张力为指标，用同步记录的方法研究了豚鼠离体小肠电活动与环肌张力、纵肌张力之间的关系，结果表明：（１）豚鼠离体小肠的电活动包括慢波与峰波；（２）豚鼠离体小肠始终存在着节律性张力活动，其环肌收缩与纵肌收缩的关系表现为拮抗收缩、共同收缩、交互抑制等形式；（３）峰波可增加收缩力，峰波的个数、振幅与小肠张力呈正变关系，尤其与环肌收缩的对应关系更为显著．（４）慢波可触发收缩，尤其是纵肌收缩．在没有峰波仅有慢波时，亦可有收缩活动甚至活跃的收缩活动．