Influence of hepatic innervation on renal glomerular filtration rate

Electrical stimulation of perivascular portal nerves leads to rapid, transient increase of renal glomerular filtration rate (GFR) and of urinary flow rate ( ). In contrast, perivascular stimulation at the vena cava inferior does not significantly alter GFR and . Spinal transfection at the thoracocervical junction does not significantly modify the effect of periportal nerve stimulation. Infusion of the -adrenergic agonist phenylephrine (20 nmol/min) into the superior mesenteric vein increases GFR and , whereas infusion of identical amounts of phenylephrine (20 nmol/min) into the jugular vein does not significantly alter GFR or . The observations indicate that -adrenergic innervation of the liver modifies renal function.     

Autonomic modulation of the U wave during phenylephrine and esmolol infusions

The etiology of U waves on the electrocardiogram is uncertain. We previously found that U waves could be amplified by isoproterenol infusion. Whether other autonomic interventions modify U-wave amplitude is unknown. Twenty-five healthy subjects underwent graded infusions of esmolol and phenylephrine. Heart rate, T-wave amplitude, U-wave amplitude, and QT and QU intervals were measured using interactive computerized electrocardiogram software. Heart rate decreased with both interventions ( P < .001), though to a greater degree with phenylephrine. U-wave amplitude increased by 16.3% during phenylephrine ( P < .001) but decreased by 14.5% during esmolol ( P < .001). The change in U-wave amplitude was strongly dose-dependent for both phenylephrine ( P < .001) and esmolol ( P < .001). T-wave amplitude increased with phenylephrine (597-692 microV, P < .001) but decreased with esmolol (632-568 microV, P < .001). QT and QU intervals increased with both interventions ( P < .001). We conclude that sympathetic and parasympathetic activities are important determinants of U-wave timing and amplitude.     

Safety of bolus-dose phenylephrine for hypotensive emergency department patients

Introduction

Bolus-dose phenylephrine (BDPE) is routinely used to treat hypotension in the operating room. BDPE's fast onset of action and ability to be administered peripherally have prompted calls for its use in the Emergency Department (ED). There are few published data on the safety of BDPE use in the ED. Primary concerns include BDPE's potential to cause dangerous hypertension or reflex bradycardia. We hypothesize that BDPE is a safe short-term vasopressor choice for hypotensive ED patients.

去氧肾上腺素维持腰-硬联合麻醉下剖宫产术中血液循环稳定的观察

目的：观察用微量泵持续静脉推注去氧肾上腺素对腰-硬联合麻醉下剖宫产术中血液循环稳定的影响。方法：选择100例择期剖宫产产妇,随机分为F组（在鞘内注局麻药即刻以25-100μg/min静脉泵入去氧肾上腺素维持循环稳定）和M组（根据血压下降程度,静注麻黄碱5 mg）。记录麻醉后多时点的血压,心率,恶心、呕吐发生情况,失血量,输液量,新生儿生后Apgar评分情况,胎儿娩出即刻脐静脉血血气分析指标。结果：F组各时点观察指标均优于M组（P〈0.05）,与麻醉前比较差异无统计学意义（P〉0.05）;M组各时点血压与麻醉前比较差异有统计学意义（P〈0.05）,心率在麻醉后5 min时减慢（P〈0.05）;F组脐静脉血气pH值、BE值均高于M组（P〈0.05）,PaCO2低于M组（P〈0.05）;F组恶心、呕吐率低于M组（P〈0.05）。结论：以25-100μg/min静脉泵入去氧肾上腺素,更能稳定腰-硬联合麻醉下剖宫产术中产妇的血液循环。     

静脉预注去氧肾上腺素联合持续泵注对无痛胃肠镜检查患者血流动力学影响的随机对照研究

目的 探讨无痛胃肠镜检查前预防性静脉注射去氧肾上腺素联合持续泵注对检查过程中患者血流动力学的影响。方法 采用前瞻性随机对照研究方法,选取2019年12月10~31日在首都医科大学附属北京友谊医院接受无痛胃肠镜检查的患者72例,利用SPSS的随机数生成器将患者随机分为去氧肾上腺素组(P组)和对照组(C组),每组各36例。P组患者在麻醉诱导给药后,立即缓慢静脉注射去氧肾上腺素50μg,同时开始静脉持续泵注去氧肾上腺素,起始剂量为30μg/min,检查过程中酌情增减泵注速度,以维持平均动脉压(MAP)波动于基础值20%以内,检查结束时停止泵注;C组患者常规给药。比较两组患者检查前、诱导给药后即刻,检查开始3 min、5 min、10 min、15 min、20 min及检查结束时的血流动力学参数(包括收缩压、舒张压、MAP和心率)、脉搏血氧饱和度、检查时间、苏醒时间、麻醉药物及血管活性药等用量和不良反应。结果 因操作方式改变,P组剔除1例。与C组(n=36)相比,P组(n=35)患者在诱导给药后,低血压的发生率较低(2. 9%vs. 36. 1%),差异具有统计学意义(P <0. 001);P组患者的MAP在诱导给药后即刻[(92±13) mmHg vs.(82±13) mmHg,P=0. 030],检查开始3 min[(87±12) mmHg vs.(77±11) mmHg,P=0. 006]、5 min[(84±11) mm Hg vs.(77±9) mm Hg,P=0. 002]、10 min[(89±8) mm Hg vs.(77±9) mm Hg,P <0. 001]、15 min[(90±9) mm Hg vs.(77±9) mm Hg,P=0. 001]、20 min[(88±8) mm Hg vs.(81±10) mm Hg,P=0. 001]、检查结束[(89±9) mm Hg vs.(84±12) mm Hg,P=0. 001]较高,但P组心动过缓(心率<50次/min)的发生率也较高(14. 3%vs. 0),差异具有统计学意义(P=0. 019);C组患者的麻黄碱用量高于P组[0(0,6) mg vs. 0(0,0) mg],差异具有统计学意义(P=0. 004)。但两组患者的脉搏血氧饱和度、胃肠镜检查时间[(20. 9±5. 8) min vs.(21. 3±6. 1) min,P=0. 752]、苏醒时间[0(0,0) min vs. 0(0,0) min,P=0. 921]、麻醉药及阿托品[0(0,0) mg vs. 0(0,0) mg,P=0. 921]等用药相比,差异无统计学意义(P> 0. 05)。结论 在无痛胃肠镜检查前,预防性静脉注射去氧肾上腺素联合持续泵注,可明显减少检查期间低血压的发生率,维持血流动力学稳定,但需警惕心动过缓的发生,必要时静注阿托品处理。     

甲基莲心碱对兔离体脑基底动脉收缩的影响

为了研究甲基莲心碱对兔离体脑基底动脉收缩的影响及与血管内皮的关系 ,采用离体家兔脑基底动脉环实验方法 ,以苯肾上腺素为兔脑基底动脉环的预收缩剂 ,测定血管张力变化 ,观察甲基莲心碱对血管收缩张力的影响 ;测定血管内皮完整组和去血管内皮组的张力变化 ,观察甲基莲心碱对血管收缩张力的影响是否为血管内皮依赖性的作用。结果发现 :甲基莲心碱抑制苯肾上腺素引起的兔脑基底动脉环收缩的作用与生理盐水对照组比较差异显著 (P <0 .0 0 1 ) ;甲基莲心碱对内皮完整组和对去内皮组血管环的最大舒张百分值分别为 38.4 %± 9.1 %和33.4 %± 1 1 .5 % ,差异无显著性统计学意义 (P >0 .0 5 )。提示甲基莲心碱能抗苯肾上腺素诱导的兔离体脑基底动脉收缩 ,其扩血管的作用主要是其直接松弛血管平滑肌所致     

苯肾上腺素预输注防治老年人脊麻后低血压的临床研究

目的 评估预防性输注苯肾上腺素用于防治老年人脊麻后低血压的疗效和安全性。方法 将2017年1月~4月在本院行骨科下肢手术且年龄超过60岁的52例患者,随机分为P组和C组,每组26例。两组患者均使用0.5%布比卡因2 ml进行腰麻,P组在腰麻注药后立即静脉给予苯肾上腺素（100 μg/ml）1 ml/min,C组给予生理盐水1 ml/min。观察两组患者的术中MAP、每例患者低血压、高血压、心动过缓的发作次数,发作低血压、高血压、心动过缓的患者数,初次低血压的发作时刻,术中最低和最高MAP,苯肾上腺素和液体的总使用量,术后6 h、24 h、48 h发生心电图改变的患者数以及肌钙蛋白增加的患者数。结果 P组MAP高于C组,初次低血压的发作时刻大于C组,差异有统计学意义（P＜0.05）。P组每例患者低血压的发作次数少于C组,差异有统计学意义（P＜0.05）。两组患者发生低血压的患者数、术中最低和最低MAP比较,差异无统计学意义（P＞0.05）。P组患者的无低血压发作的累计比例高于C组,差异有统计学意义（P＜0.05）。两组患者术中发生高血压和心动过缓例数、每例患者高血压和心动过缓的发作次数、术中液体总使用量比较,差异无统计学意义（P＞0.05）。P组的苯肾上腺素总使用量高于C组（P＜0.05）。两组患者在术后6 h、24 h均未发生心电图异常改变情况。P组患者在术后48 h内未发生心电图异常改变情况,C组有2例患者（7.69%）在术后48 h发生了心电图异常改变,两组差异无统计学意义（P＞0.05）。C组患者在术后6 h、24 h、48 h发生肌钙蛋白定量升高的患者数均高于P组,但差异无统计学意义（P＞0.05）。结论 预防性输注苯肾上腺素可有效防治老年人脊麻后低血压,减少低血压发作次数,延迟低血压发作时间,提高手术麻醉的安全性。     

蜂毒肽对大鼠主动脉收缩的作用及与钙内流的关系

为探讨蜂毒肽对心血管系统的作用机理,利用离体大鼠主动脉收缩实验及血管平滑肌细胞＾４５Ｃａ内流定量测定方法,观察了蜂毒肽对血管平滑肌的影响。结果发现：蜂毒肽不影响内皮完整主动脉由苯肾上腺素引起的快速收缩,但可溶度依赖地抑制持续收缩;蜂毒肽对去内皮主动脉环由苯肾上腺素引起的收缩无作用;蜂毒肽对内皮完整主动脉未能产生收缩反应,但可使去内皮动脉环产生收缩和＾４５Ｃａ内流增加,卡手普利和苄普地尔能部分拮抗这     

Baroreceptor-heart rate reflex sensitivity enhancement after urinary bladder distention in essential hypertensives

Our objective was to determine if urinary bladder distention modifies the sensitivity of the baroreceptor-heart rate reflex in hypertensive and control subjects. The baroreceptor-heart rate reflex sensitivity was measured in 15 male patients (mean age 37 ± 8 years) with mild untreated hypertension (mean 163 ± 8/95 ± 12 mmHg) and 17 age- and sex-matched control subjects before and after urinary bladder distention. Bladder filling was performed infusing saline heated to 37°C via a urinary catheter; the volume infused in each patient corresponded to that which caused the urge to void without reaching the pain threshold. The baroreceptor-heart rate reflex sensitivity was determined correlating the variations of the systolic pressure and of the peak blood flow velocity in the common carotid artery with the variations of the ECG RR′ interval of the following heart beat, both during spontaneous and phenylephrine-induced fluctuations of the haemodynamic variables. After bladder distention the diastolic pressure of the hypertensive subjects increased significantly (95 ± 12 vs. 100 ± 12 mmHg; P < 0.02), whereas the heart rate decreased (RR=873 ± 70 vs. 926 ± 80 ms; P < 0.005). These parameters were unchanged in the normotensive subjects (84 ± 9 vs. 83 ± 8 mmHg and 914 ± 158 vs. 913±140 ms, respectively). The baroreceptor-heart rate reflex sensitivity, measured on the basis of spontaneous pressure and carotid blood flow velocity fluctuations in relationship to RR changes, decreased in the normotensive subjects after bladder distention (10.7 ± 4.6 vs. 9.4 ± 2.7 ms/mmHg; P < 0.05 and 423 ± 99 vs. 356 ± 102 ms/kHz; P < 0.01, respectively), whereas it increased in the hypertensive patients (6.9 ± 3.6 vs. 8.3 ± 2.8 ms/mmHg; P < 0.03, and 332 ± 86 vs. 381 ± 97 ms/kHz; P < 0.03 respectively). After bladder distention and phenylephrine administration the baroreceptor-heart rate reflex sensitivity, measured by the correlation between systolic pressure and RR interval, increased only in the hypertensive group (10.2 ± 5.4 vs. 15.2 ± 7.7 ms/mmHg; P < 0.005). In conclusion urinary bladder distention provokes in hypertensives but not normotensive controls a brisk parasympathetic response of the component of the baroreceptor-heart rate reflex which controls heart rate. Received: 17 June 1998 / Accepted: 20 October 1998     

HPLC法测定含对乙酰氨基酚、氢溴酸右美沙芬和盐酸去氧肾上腺素的软胶囊有关物质

目的 建立测定同时含对乙酰氨基酚、氢溴酸右美沙芬和盐酸去氧肾上腺素的软胶囊有关物质的方法.方法 采用高效液相色谱法,以Agilent Zorbax Plus C18(150×4.6 mm,5μm)为色谱柱;流动相A为1-辛烷磺酸钠和乙酸铵的水溶液,流动相B为乙腈-冰醋酸(100:1),梯度洗脱为0 min→15 min...