血浆NO和ET—1在内毒素休克进程中的动态变化及其与休克发病的关系

观察内毒休克进程中，家兔血浆ＮＯ的内皮素浓度的动态变化，探讨两者变化规律及可能的致病作用。方法采用离子色谱法及放射免疫法分别检测血浆ＮＯ、ＥＴ含量并记录血流动力学各项指标。     

Endothelin acts at the subfornical organ to influence the activity of putative vasopressin and oxytocin-secreting neurons

Systemic endothelin-1 (ET-1) enhances the activity of subfornical organ (SFO) neurons with identified projections to the paraventricular nucleus of the hypothalamus (PVN). The present electrophysiological experiments were undertaken to examine the mechanisms through which systemic ET influences vasopressin secretion. Systemic ET-1 (50-100 pmol) was found to influence the excitability of antidromically identified vasopressin and oxytocin-secreting neurons in the PVN or supraoptic nucleus (SON) of urethane-anaesthetized rats. Long-term stable recordings from 95 antidromically identified neurons showed 56% of putative vasopressin- (n = 41), and 37% of putative oxytocin- (n = 54) secreting neurons were activated by ET-1. Such effects normally demonstrated a short latency (less than 10 s), with a duration ranging between 10 and 300 s. In contrast, unidentified neurons in the vicinity of PVN and SON (n = 27) were unaffected by ET-1. The inability of peptides to cross the normal blood-brain barrier suggested that such effects of ET-1 result from actions of this peptide at the SFO which lacks this barrier and sends efferent neural projections to both SON and PVN. This hypothesis was tested by obtaining similar recordings from animals in which this structure was destroyed prior to experimentation. In these studies recordings from 15 putative vasopressin- and 29 putative oxytocin-secreting neurons showed that only 7% and 14%, respectively, were excited by systemic ET-1 in lesioned animals. These data show that increases in circulating levels of ET have predominantly excitatory effects on vasopressin- and oxytocin-secreting neurons in SON and PVN. The modified responsiveness of these neurons to ET-1 in SFO-lesioned animals suggests this as a likely CNS site at which this peptide acts within the central nervous system to elicit such effects.     

Endothelin Potentiates Growth Factor-stimulated DNA Synthesis in Swiss 3T3 Cells

A murine cell line, Swiss 3T3, is commonly used for the study of cellular growth. The present study revealed that this cell line possesses high-affinity receptors for endothelin, a vasoactive peptide derived from vascular endothelial cells. In this cell line, endothelin potentiated DNA synthesis stimulated by platelet-derived growth factor, basic fibroblast growth factor or insulin. The endothelin concentration required for potentiating DNA synthesis in this cell line is almost the same as that reported previously in endothelin-induced vasoconstriction. Since endothelin increased intracellular calcium levels, this ion may participate in the signal transduction pathways by which endothelin induces potentiation of DNA synthesis.     

Design of hydropathically complementary peptides for Big Endothelin affinity purification

Molecular recognition between Big Endothelin (Big ET) and a computer generated peptide hydropathically complementary to Big ET[16-29] sequence has been studied by analytical high performance liquid affinity chromatography (HPLAC), circular dichroism (CD) and nuclear magnetic resonance (NMR) experiments. Specific binding was observed between solid support immobilized complementary peptide and Big ET[1-38], [1-32], and [16-32], but not with Big ET fragments [1-21], [16-21], [22-32], and [22-38], obtained by chymotrypsin proteolytic degradation. Selectivity in the recognition process was clearly demonstrated by the ability of complementary peptide affinity column to purify the Big ET molecule from complex peptide mixtures, even when present in very low concentrations. Similar selectivity was evidenced with the Big ET fragment [16-32], [NH₂-HLDIIWVNTPEHIVPYG-COOH] containing the entire hydropathically complementary sequence. Binding was followed by marked spectroscopic changes, as monitored by circular dichroism and one- and two-dimensional nuclear magnetic resonance experiments. The NMR spectra of the complementary peptides 1:1 mixture showed variations in the chemical shifts of proton resonances in several residues, both in the main chain (amide protons) and in the side chains (aliphatic and aromatic protons). These data support the hypothesis of a multilocalized type of interaction between complementary peptides, where many residues along the peptide chains participate in co-operative stabilizing contacts in the forming complex.     

机械通气对危重症伴呼吸衰竭患者血浆内皮素水平的影响

目的　探讨呼吸功能不全等危重病患者接受机械通气治疗时血浆内皮素变化的临床意义。方法　 5 8例呼吸功能不全等危重病患者为观察组 ,38例健康体检者为对照组 ,机械通气治疗前后测定血浆内皮素浓度。结果　观察组机械通气前的血浆内皮素平均浓度为 (6 5 79± 2 1 78)pg/mL ,明显高于对照组的(4 8 87± 10 96 )pg/mL ,(P <0 0 1)。观察组机械通气治疗后第 3天 ,血浆内皮素平均浓度为 (36 39±16 39)pg/mL (P <0 0 1)。结论　机械通气是治疗呼吸功能不全、减少内皮素对机体的损害的有效措施。血浆内皮素浓度的变化 ,对危重症伴呼衰患者病情严重程度和转归的判断、疗效评价有一定参考价值。     

慢性肾病患者血液透析前后内皮素的变化

建立了内皮素的放射免疫分析法，并用以观察了２２例慢性肾炎患者和１１例慢性肾衰患者血液透析前后免疫活性内皮素（ｉｒ－ＥＴ）的动态变化。结果表明慢性肾炎及慢性肾衰患者血浆ＥＴ含量均明显著增高（Ｐ＜０．０１），但后者更明显；血透后血浆ＥＴ含量显著降低（Ｐ＜０．０５），但仍高于对照组；透析过程中，血液通过透析器前后ＥＴ含量不变，透析液中ＥＴ含量极低，表明血浆ＥＴ不能从透析液中滤出。结果提示ＥＴ可能是一种促     

消化系统疾病血浆内皮素的含量变化

内皮素（ET）是目前已知的内源性物质中具有最强作用的缩血管剂，消化系统可自行分泌ET，而且有大量ET受体，故ET与消化系统疾病有着相当密切的关系，而且与疾病的程度呈正相关。我们观测了262例已明确诊断的消化系统疾病病人，取血检测其血浆ET含量，并根据不同疾病分组，分别与正常对照组ET水平相比较，证实诸如肝硬化、肝癌、溃疡病、胃肠炎等疾病组血浆ET水平显著高于健康对照组。各组检测数据还提示了血浆ET在几种消化系统疾病中的存在情况。ET水平的高低直接与病变的程度相关。     

海水淹溺大鼠肺脏内皮素及降钙素基因相关肽含量的变化

目的　研究低温海水淹溺大鼠肺脏内皮素 (ET)及降钙素基因相关肽 (CGRP)含量变化规律 ,探讨二者对肺脏功能的影响。方法　将大鼠随机分为对照组和淹溺组。淹溺组大鼠分别置于 16～ 18℃海水中自由游动 ,于淹溺后 5 ,15 ,30 ,6 0 ,2 4 0 ,36 0 m in及死亡后测量肛温 ,自左心室取血 1ml行血气分析 ,处死动物取左肺计算肺干湿重比值 ,取右肺检测 ET和 CGRP含量。结果　海水淹溺后 ,不同时间组动物肛温、肺组织干湿重比值、p H、Pa O2 明显降低 ,其中肛温、p H、Pa O2 于 5 min时降至最低点 ,肺组织干湿重比值于 6 0 m in降至最低点 ;Pa CO2 则明显升高 ,于 5 m in组升至最高点 ;随后上述指标呈恢复趋势 ,然而除 p H于 2 4 0及 36 0 min时接近正常对照水平外 (P>0 .0 5 ) ,其余均仍未恢复到正常对照组水平 (P<0 .0 1)。 ET含量于 30 min和 CGRP含量于 15 m in分别降至最低点 [(15 .6 8± 6 .5 3) ng/ L及(34.4 7± 5 .5 8) ng/ L ],与正常对照组相比差异有显著性 (P<0 .0 1) ,随后呈上升趋势 ,前者至 2 4 0 m in高达 (5 8.92± 6 .39) ng/ L ,比正常对照组 (30 .72± 7.0 6 ) ng/ L明显增高 (P<0 .0 1) ,36 0 min时 (2 5 .6 9±4 .2 7) ng/ L恢复接近正常对照组水平 (P>0 .0 5 ) ;后者至 36 0 m in时 (49.6     

内皮素在体外循环心脏直视手术期间的变化

报告１０例体外循环（ＣＰＢ）心脏手术病人的内皮素（ＥＴ）测定结果。提示：（１）１０例ＣＰＢ病人术前ＥＴ含量为１７３．３±６４．４ｐｇ／ｍｌ，明显高于术中与术后（Ｐ＜０．０１）。（２）心脏复苏后不久，ＥＴ值达到了最低点４６．２±３８，０ｐｇ／ｍｌ，与心脏阻断后及回ＩＣＵ病房后的ＥＴ含量比较（Ｐ＜０．０５）。（３）术后ＥＴ含量开始回升，但仍低于术前水平。故作者认为ＣＰＢ过程没有必要应用ＥＴ拮抗剂。     

高温、噪声及其复合对大鼠血浆和肺组织中内皮素含量的影响(论著)

目的：测定高温、噪声及其复合对大鼠血浆及肺组织中内皮素（ET）含量的影响。方法：80只Wistar大鼠随机分为4组，即对照组、高温组、噪声组及复合组。后3组分别进行高温（40℃，相对湿度82％）、噪声（115dBA）及高温与噪声复合暴露，各组暴露时间1小时。用特异性放射免疫法进行检测。结果：（1）对照组、高温组、噪声组及复合组血浆ET含量分别为821．5±49．3、786．8±46．0、823．6±58．6及703．1±29．6pg／ml，复合组血浆ET含量较对照组明显下降（P＜0．05）。（2）对照组、高温组、噪声组及复合组肺ET含量分别为21．6±7．6、53．6±15．1、45．1±7．1及17．2±2．3pg／mgWW，噪声组肺ET含量较对照组明显升高（P＜0．05）。结论：噪声组肺ET含量明显升高与噪声使交感神经紧张性增加，肺组织缺氧有关。ET是目前已知最强的支气管收缩剂，故强噪声可引发支气管哮喘。ET对心肌具有剂量依赖性正性肌力作用，可使血浆中加压素、肾上腺素水平增加。复合组血浆ET含量下降可能会使心肌收缩力减弱，血压下降，进而出现心慌、头晕、疲乏等症状，使工作耐力下降。