The basal and stimulated release of the endothelium-derived relaxing factor from isolated pig coronary arteries does not interfere with the vascular release of superoxide

Oxygen-derived free radicals, in particular superoxide anions, are known to inactivate the endogenous vasodilator endothelium-derived relaxing factor (EDRF) which is probably identical with the gaseous radical nitric oxide. It is possible that EDRF is not the target of superoxide anions but may also be an endogenous scavenger of this radical.Superoxide anions generated by the vessel wall were measured by a modified lucigenin-enhanced chemiluminescence technique in isolated pig coronary artery rings with intact endothelium.The addition of bovine superoxide dismutase, a scavenger of superoxide anions, decreased the chemiluminescence signal by 40 ± 26% (mean ± SD; P < 0.05; n = 21) indicating reduced generation/release of superoxide anions. In contrast, pretreatment of coronary artery rings with diethyldithiocarbamate, an inhibitor of the intrinsic copper-zinc superoxide dismutase, increased the chemiluminescence response by 136 ± 128°10 (P < 0.05; n = 21). This increase in the chemiluminescence response induced by diethyldithiocarbamate-pretreatment was almost abolished in the presence of added bovine superoxide dismutase. Specific inhibition of the EDRF release with nitro-l-arginine (100 M) did not affect the chemiluminescence response. On the other hand, stimulation of the EDRF release by substance P (10 nM) or addition of the endothelium-mediated relaxant bradykinin (0.1 M) did not affect the chemiluminescence response. Stimulation of the EDRF release with serotonin (0.1 M) significantly reduced the photon emission by 15 ± 16% (n = 27). However, this effect of serotonin on the chemiluminescence response could not be prevented by specific inhibition of the EDRF release with nitro-l-arginine (100 M) but could be prevented by buffering the acidic serotonin solution with NaOH to pH 7.4.Our results suggest that basal and agonist-stimulated release of EDRF in isolated pig coronary artery rings does not interfere with the basal generation/release of superoxide anions derived from the vascular wall. Correspondence to: A. Mugge at the above address     

Syndrome X in women is associated with oestrogen deficiency

This study was undertaken to ascertain whether gynaecologicalhistory or a reduction in ovarian hormones are triggers of anginain menopausal women with a positive exercise test and normalcoronary arteries. The majority of patients with angina pectoris,a positive exercise test and normal coronary arteries are female,suggesting that the female gender may be important in the aetiology.We studied the gynaecological features of 107 women (age 53±9 years) with syndrome X, taken from a population of134 patients including 27 males. Cardiological investigationswere undertaken and detailed gynaecological history obtainedfrom all the female patients. Menopausal status was confirmedby plasma levels of oestradiol-17ß100 pmol. l^–1. In 95 of the 107 female patients, chest pain began either duringthe perimenopausal period (32) or after the menopause (63).Of the 63 menopausal patients, 43 had undergone hysterectomyat an average of 8 ± 6 years prior to the onset of chestpain. The incidence of hysterectomy in the study population(40%) was four times greater than that of an age-matched population.These findings confirm that the majority of patients with syndromeX are women in whom the chest pain began after the onset ofmenopause. Ovarian hormone deficiency may, therefore, play arole in the onset of syndrome X in female patients.     

Intramural hydatid cysts of pulmonary arteries: CT and MR findings

Involvement of the pulmonary artery by echinococcosis usually occurs due to pulmonary embolization after rupture of the cyst in the right ventricle or, rarely, by dissemenation from a hepatic focus. This paper presents an adult patient with intramural hydatid cysts of the pulmonary arteries, which apparently grew slowly toward the lumina resulting in complete luminal occlusion, enabling sufficient time for development of sufficient perfusion from the bronchial arteries. The condition apparently resulted from embryos of the parasite, which entered the vasa vasorum of the pulmonary arteries, a previously unreported mechanism.     

原代培养人脐动脉内皮细胞的超微结构

对不用贴附基质和生长因子情况下原代培养７２ｈ的人脐动脉内皮细胞（ＨＵＡＥＣ）进行了透射电镜观察。电镜下ＨＵＡＥＣ形态不规则,细胞器丰富。核周有散在的滑面内质网、粗面内质网及较多的线粒体,后者有些为板层状嵴,另一些为管泡状嵴。细胞膜下可见微管,胞质内有大量循同一方向排列的微丝。Ｗｅｉｂｅｌ Ｐａｌａｄｅ小体内含涡旋状排列的细管。胞质内含丰富的糖原颗粒。细胞核内常染色质较多,异染色质主要分布于核膜下。有时可见处于无丝分裂状态的细胞,核已分裂为二,但二者间仍有核膜相连。内皮细胞间以紧密连接或中间连接的方式相连。以上结果表明：人脐动脉内皮细胞在体外培养条件下代谢功能旺盛,且具有参与脂类代谢的细胞器,细胞以无丝分裂方式增殖。     

Effects of propofol on isolated human pial arteries

BACKGROUND: The intravenous anaesthetic propofol has been reported to increase cerebral vascular resistance in vivo. The underlying mechanisms are not fully understood, but may include effects on metabolism and direct effects on the vascular smooth muscle. The present study was designed to evaluate the direct effects of propofol on human pial arteries. METHODS: We investigated the direct effect of propofol (10(-6)-10(-4) M) on isolated human pial arteries at basal tension as well as the influence on contractions induced by 5-hydroxytryptamine, prostaglandin F2alpha, noradrenaline and potassium chloride. RESULTS: Propofol did not change the basal tension. Propofol at 10(-6) and 10(-5) M did not affect the concentration-response curves of any of the contractile agents tested. Propofol at the supraclinical concentration 10(-4) M reduced the contractions induced by all contractile agents. CONCLUSION: Propofol reduces the tone of human pial arteries in vitro at supraclinical concentrations, but has no effect on the tone at clinically relevant concentrations.     

Aortopulmonary collateral artery embolization during postoperative extracorporeal membrane oxygenation after arterial switch procedure

Aortopulmonary collateral arteries sometimes complicate cyanotic congenital heart defects. Combined with a relevant left-right shunt, this could result in massive airway bleeding during and after corrective surgery. A preoperatively diagnosed 1.2 mm small aortopulmonary collateral artery in a newborn suffering from transposition of the great arteries caused life-threatening airway bleeding during surgery. Postoperative extracorporeal membrane oxygenation (ECMO) was necessary, and coil embolization was performed on ECMO to terminate pulmonary bleeding.     

妊高征患者胎儿脐血流速度与围产儿预后的关系

目的：探讨妊高征患者胎儿脐动脉血流速度比值（Ｓ／Ｄ）与围产儿预后的关系,方法：应用彩色超声波对９８例妊高征患者胎儿脐动脉血流速度指数进行测量并与新生儿体重,新生儿Ａｐｇａｒ评分,羊水性质和围产期结局的关系进行分析,结果：９８例妊高征中有３４例围产儿预后良好,６４例围产儿预后不良,围产儿预后不良发生率,中,重度妊高征明显高于轻度妊高征（Ｐ〈０．０１）,Ｓ／Ｄ比值与围产儿预后的程度业的相关性,结论,产     

Contractile effect of big endothelin-1 and its conversion to endothelin-1 in rabbit cerebral arteries

The effect of big endothelin-1 (big ET-1) and its conversion to endothelin-1 (ET-1) in rabbit cerebral arteries were examined. Big ET-1 and ET-1 induced concentration-dependent contractions in the basilar artery; ET-1 was approximately 8 times more potent than big ET-1. The metalloprotease inhibitor phosphoramidon (30 ol/1) almost abolished the contractile response to big ET-1, whereas the ET-1-induced contraction was unaffected. Removal of the endothelium did not attenuate the big ET-1-induced contraction. ET-1 was approximately 14 times more potent than endothelin-3 (ET-3) to elicit contraction. The contractions induced by big ET-1, ET-1 and ET-3 were all inhibited by the ET_A receptor antagonist BQ 123 (3 mol/l). The ET_B receptor antagonist IRL 1038 (3 mol/l) had no effect on the contractile responses to big ET-1 and ET 1, but produced a small inhibition of the ET-3-induced contraction. Formation of ET-1 was demonstrated in membrane fractions of cerebral arteries incubated with big ET-1 as measured by high pressure liquid chromatography followed by radioimmunoassay. These results suggest that externally applied big ET-1 is converted to ET-1 by a phosphoramidon-sensitive endothelin converting enzyme present in the vascular smooth muscle cells. The ET-1 formed subsequently mediates the big ET-1-induced contraction by activation of mainly ETA receptors, although a small contribution of ETB receptors cannot be excluded.     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: STRUCTURAL CHANGES IN THE RENAL VASCULATURE IN THE SPONTANEOUSLY HYPERTENSIVE RAT: NO EFFECT OF ANGIOTENSIN II BLOCKADE

• 1 There is strong evidence for a renal basis to the development of hypertension in the spontaneously hypertensive rat (SHR). Alterations of the SHR renal vasculature, including the glomerulus, may be involved in the initiation and maintenance of hypertension in this animal model.
• 2 The arterial walls of pre-glomerular vessels of the SHR are hypertrophied compared with WKY vessels. Unlike other vascular beds in the SHR, this hypertrophy is independent of angiotensin II (AngII).
• 3 Glomerular number and volume are similar between SHR and the normotensive Wistar-Kyoto (WKY) rats. These results provide no support for the theory that a reduced filtration surface area within the kidneys of the SHR contributes to the elevated blood pressure in these animals.
• 4 Intrarenal hypertrophy may have similar haemodynamic consequences to clipping of the main renal artery, as in Goldblatt hypertension. Further analysis of the role of pre-glomerular arterial hypertrophy is warranted to determine its involvement in the initiation and maintenance of hypertension in the SHR.

     

Patterns of the coronary artery irrigation in the left ventricle

Summary Nowadays, the classifications of coronary arterial preponderance (Schlesinger, Baroldi, Gensini) do not provide the necessary information for a good systematization of coronary arterial irrigation. Based on segmental analysis (Selvester's method) an alternative classification of the arterial distribution of the left ventricle is presented. One thousand eighty ventricle segments corresponding to 90 human hearts (age range from 4 days to 94 years) are studied, using microdissection techniques. In order to obtain segmental arterial patterns, a cluster analysis was used. The alternative classification is based on the predominance of the segments irrigated by: the anterior interventricular artery (Type I; 31% of cases), the circumflex artery (Type II; 37% of cases), or a balance between both arteries (Type III; 32% of cases). Each group can be divided into two subgroups (A and B), according to the existence or not of a balance between the territories of anterior interventricular and circumflex arteries. This classification allows as a more realistic approach to the subject of arterial dominance, given that the left ventricle always presents a predominant irrigation from the anterior interventricular, the circumflex or both arteries.

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Essai de classification de l'irrigation artérielle coronaire du ventricule gauche

Résumé La classification en dominance artérielle coronaire, actuellement utilisée (Schlesinger, Baroldi, Gensini) ne donne pas toutes les informations nécessaires à une bonne systématisation de la distribution des artères coronaires. Nous présentons ici une classification alternative, basée sur la segmentation des parois du ventricule gauche à la manière de Selvester. 1080 segments ventriculaires gauches de 90 coeurs humains prélevés sur des sujets de 4 jours à 94 ans ont été analysés en utilisant les techniques de microdissection. La présente classification est basée sur — la prédominance de segments irrigués par l'artère interventriculaire antérieure (IVA) : type I, par l'artère circonflexe (CX) : type II, — ou sur l'existence d'un équilibre entre ces deux artères : type III. Le pourcentage de distribution de ces groupes est le suivant : type I : 31 % ; type II : 37 % ; type III : 32 %. Chacun de ces groupes peut-être divisé en deux sous-groupes A et B selon — la prédominance du nombre de segments irrigués exclusivement ou en partage par l'IVA, — ou l'existence d'un équilibre entre l'IVA et la CX. Cette classification permet une approche plus réaliste du problème de dominance artérielle, étant donné que le ventricule gauche est toujours irrigué en prédominance par l'IVA, par la CX ou à la fois par les deux.