强啡肽抑制离体血管收缩效应的机制

用离体血管电场刺激收缩模型观察到强啡肽明显抑制电场刺激引起的兔耳中心动脉及兔肠系膜上动脉的收缩效应,且呈剂量反应关系,而对股动脉的电场刺激收缩反应无明显影响,强啡肽抑制血管收缩达50％时的用量(IC_(50)值)分别为8.5±1.2×10~(-6)mol/L、5.02±1.3×10~(-7)mol/L及>10~(-6)mol/L。 用药物分析法看到,酚妥拉明(10~(-6)mol/L)可取消电场刺激及去甲肾上腺素引起的血管收缩作用,而强啡肽仅抑制电场刺激致血管收缩作用。 用HPLC法测定孵育液中去甲肾上腺素的含量变化时看到,应用强啡肽(5×10~(-7)mol/L)后孵育液中去甲肾上腺素的含量从对照组的340.56±73.13pg/ml下降至67.91±10.26pg/ml,两组差别有极显著意义(P<0.01)。纳洛酮(10~(-6)mol/L)可完全拮抗强啡肽的这一抑制效应。 以上结果提示强啡肽可能通过抑制交感神经末梢释放去甲肾上腺素,从而产生抑制血管的收缩作用。     

慢性缺氧对肺动脉内皮依赖性和非内皮依赖性舒张反应的影响

本实验用生物测定法观察了模拟海拔5000m高度连续缺氧20d对大鼠肺动脉内皮依赖性和非内皮依赖性舒张反应的影响。结果显示慢性缺氧明显抑制了肺内和肺外动脉对乙酰胆碱、ATP、硝普钠和异丙肾上腺素舒张反应的敏感性和反应性。在浓度为10~(-6)mol/L时,缺氧组大鼠肺内动脉对乙酰胆碱、硝普钠和异丙肾上腺素的舒张反应分别只有对照组大鼠的61.3％、75.9％和61.7％,对浓度为1.8×10~(-5)mol/L的ATP的舒张反应只有对照组大鼠的64.9％。研究表明,ATP和乙酰胆碱主要是通过内皮舒张因子使肺动脉产生内皮依赖性舒张反应,硝普钠和异丙肾上腺素分别通过直接激活血管平滑肌细胞鸟苷酸环化酶和β受体使血管产生非内皮依赖性舒张反应。缺氧同时抑制了肺动脉内皮依赖性和非内皮依赖性舒张反应,提示慢性缺氧可能抑制了正常肺内舒血管活性物质的生理作用。     

Age-dependent aluminum accumulation in the human aorta and cerebral artery

The purpose of this study was to determine the extent of aluminum (Al) accumulation in the human aorta and cerebral arteries. The Al contents in the aortae and in the cerebral arteries from 23 human subjects was determined by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). The subjects' age range was 45–99-yr-old; 15 of the subjects were males and 8 were females. Al was detected in twelve aortae and in six cerebral arteries, when the entire specimen was analyzed. Two specimens where Al was found in the cerebral arteries contained no Al in the aorta. No relationship to the subject's sex was found. When related to age, two groups were established. Group L (45–75 yr old) and group H (>75 yr old), which exhibited aortal Al concentrations of 33.3 and 72.7%, respectively. When the aortic wall was dissected into the tunica intima, media, and adventitia, Al was found mainly in the tunica media. In the aorta, significant relationships were found between Al and phosphorus (P) levels (r=0.801,p<0.01) and between Al and calcium (Ca) (r=0.661,p<0.05). We have concluded that Al accumulation is age-dependent and that it occurs both in the aorta and in the cerebral artery. In the aorta, accumulation occurs mainly in the tunica media. Both P and Ca appear to enhance aortal Al accumulation.     

The bronchial tree,lobular division,and blood vessels of the lung of the silvered lutong (Presbytis cristata)

The lungs of three silvered lutongs (Presbytis cristata) were examined. The right and left lungs have the dorsal, lateral, ventral, and medial bronchiole systems, which arise from the corresponding sides of both bronchi, respectively. Bronchioles in the dorsal and lateral bronchiole systems are well developed, whereas those in the ventral and medial bronchiole systems are poorly developed and lack some portions. According to the fundamental structure of bronchial ramifications of the mammalian lung (Nakakuki, 1975, 1980), the right lung consists of the upper, middle, lower, and accessory lobes, whereas the left lung consists of a bilobed middle lobe and a lower lobe, in which the right upper lobe is extremely well developed. The right pulmonary artery runs across the ventral side of the right upper lobe bronchiole, and then across the dorsal side of the right middle lobe bronchiole. Initially it runs along the lateral side of the right bronchus and then gradually comes to run along the dorsal side. During its course, it gives off branches which run mainly along the dorsal or lateral side of the bronchiole. The left pulmonary artery runs across the dorsal side of the left middle lobe bronchiole, and then follows the same course as that in the right lower lobe. The pulmonary veins run medially or ventrally to the bronchioles, and finally enter the left atrium as four or five large veins.     

Properties of the ATP-sensitive K+ current activated by levcromakalim in isolated pulmonary arterial myocytes

Tension and patch clamp recording techniques were used to investigate the relaxation of rabbit pulmonary artery and the properties of the K⁺ current activated by levcromakalim in isolated myocytes. Under whole-cell voltage clamp, holding at –60 mV in symmetrical 139 mm K⁺, levcromakalim (10 m) induced a noisy inward current of –116 ± 19 pA (n = 13) which developed over 1 to 2 min. This current could be blocked by either glibenclamide (10 m) or phencyclidine (5–50 M) and was unaffected when extracellular Ca²⁺ was removed. Both these drugs inhibited the levcromakalim-induced relaxation of muscle strips precontracted with 20 mm [K⁺] _o . Application of voltage ramps in symmetrical 139 mm K⁺ confirmed that the levcromakalim-induced current was carried by K⁺ ions and was weakly voltage dependent over the potential range from –100 to +40 mV.The unitary current amplitude and density of the channels underlying the levcromakalim-activated whole-cell K⁺ current was estimated from the noise in the current record. We estimate that levcromakalim caused activation of around 300 channels per cell, with a single channel current of 1.1 pA, corresponding to a slope conductance of about 19 pS. Furthermore, cells dialyzed with an ATP-free pipette solution developed a large noisy inward current at –60 mV, which could subsequently be blocked by flash photolysis of caged ATP. Analysis of the noise associated with this current indicated that the single channel amplitude underlying the ATP-blocked current was 1.4 pA, a value similar to that estimated for the levcromakalim-induced current. We conclude that the conductance of this ATP-sensitive channel is likely to be small under physiological conditions and that it is present at low density.We thank SmithKline & Beecham for the gift of levcromakalim, ICI Pharmaceuticals for the gift of charybdotoxin and Prof. D. Colquhoun for the noise analysis programs. We also thank Mr. R. Davey for technical assistance with tension experiments. This work was supported by the British Heart Foundation and the Wellcome Trust. L.H.C. is a Wellcome Research Fellow and P.L. is an intermediate fellow of the BHF.     

DNA fingerprint bands applied to linkage analysis with quantitative trait loci in chickens

Summary
An efficient approach to detect association between quantitative traits and bands of DNA fingerprint patterns uses intra-family tail analysis, which compares fingerprints of DNA mixes from individuals at the two tails of a phenotypic distribution. In analysis of 67 paternal half-sibs of a meat-type chicken family, of 57 sire bands generated by two probes, one sire-specific band (S6–6) was associated with abdominal fat deposition. The band effect was estimated by a linear model analysis to be 0–88 standard deviations, or about 30% of the family mean. The association between band S6–6 and abdominal fat was further examined by testing progeny of paternal half-sibs of the chickens which were used in the tail analysis, establishing genetic linkage between the DNA marker and a genetic locus affecting abdominal fat deposition.     

血清GDF-15、hs-cTnT对冠状动脉旁路移植术后新发房颤及近期主要心血管事件的预测效能研究

摘要 目的：分析血清生长分化因子15（GDF-15）、高敏心肌肌钙蛋白T（hs-cTnT）对冠状动脉旁路移植术后新发心房颤动（房颤）及近期主要心血管事件的预测效能。方法：选择自2020年1月至2022年1月在我院行冠状动脉旁路移植术的140例冠心病患者作为研究对象,根据术后是否新发房颤,分为房颤组（46例）和非房颤组（94例）。检测两组术前血清GDF-15、hs-cTnT水平,使用多因素Logistic回归分析血清GDF-15、hs-cTnT与术后新发房颤的关系;随访6个月,观察主要心血管事件发生情况,通过受试者工作特征曲线下面积（AUC）评价血清GDF-15、hs-cTnT对术后新发房颤及近期主要心血管事件的预测效能。结果：两组患者年龄、性别、体重指数等一般资料比较无差异（P＞0.05）;房颤组SYNTAX积分高于非房颤组,差异有统计学意义(P＜0.05);房颤组血清GDF-15、hs-cTnT水平均高于非房颤组（P＜0.05）;经多因素Logistic回归分析,SYNTAX积分、血清GDF-15、hs-cTnT均是冠状动脉旁路移植术后新发房颤的独立预测因素（P＜0.05）;经ROC曲线分析,血清GDF-15联合hs-cTnT预测冠状动脉旁路移植术后新发房颤的AUC为0.933,大于SYNTAX积分的0.790,预测近期主要心血管事件的AUC为0.925,大于SYNTAX积分的0.750（P＜0.05）。结论：血清GDF-15联合hs-cTnT对冠状动脉旁路移植术后新发房颤及近期主要心血管事件均具有良好的预测效能,值得临床予以重视。     

高血压前期患者颈动脉血管弹性超声参数与左室舒张功能的关系研究

摘要 目的：研究高血压前期患者颈动脉血管弹性超声参数与左室舒张功能的关系。方法：选取2019年12月-2020年12月因血压异常于河北北方学院附属第一医院接受诊断与治疗的161例患者,根据血压水平分为高血压前期组（82例）与高血压组（79例）;另选取同期于我院体检的80例健康志愿者作为对照组。收集三组临床资料,检测生化指标与血压;通过超声诊断仪中超声射频信号血管内中膜定量分析（QIMT）与动脉僵硬度定量分析（QAS）软件测量颈动脉血管弹性超声参数[颈动脉内中膜厚度（IMT）、顺应性系数（CC）、扩张性系数（DC）、血管弹性指数（α、β）、脉搏波传导速度（PWV）];超声心动图检查左室功能指标[左室射血分数（LVEF）、左室质量指数（LVMI）、舒张早期血流速度峰值（E）/舒张晚期血流速度峰值（A）、等容舒张时间（IVRT）、舒张期减速时间（DT）];采用Pearson相关性法分析颈动脉血管弹性超声参数与心室指标的相关性。结果：三组收缩压与舒张压水平存在统计学意义（P＜0.05）。高血压前期组与高血压组IMT、α、β、PWV高于对照组,DC、CC低于对照组（P＜0.05）,且高血压前期组IMT、α、β、PWV低于高血压组,DC、CC高于高血压组（P＜0.05）。高血压前期与高血压组E/A低于对照组,IVRT、DT高于对照组（P＜0.05）,且高血压前期组E/A高于高血压组,IVRT、DT低于高血压组（P＜0.05）。经Peason相关性分析显示,IMT、α、β、PWV与E/A呈负相关,与IVRT、DT呈正相关（P＜0.05）;DC、CC与E/A呈正相关,与IVRT、DT呈负相关（P＜0.05）。结论：高血压前期患者颈动脉血管弹性功能下降,且伴有左室舒张功能受损,颈动脉血管弹性超声参数与左室舒张功能密切相关。