PAMP增强肾上腺素和去甲肾上腺素升血糖的作用

我们在研究肾上腺髓质素前体Ｎ端２０肽（ＰＡＭＰ）时，发现应用ＰＡＭＰ剂量在３０．０ｎｍｏｌ／ｋｇ时可引起大鼠心律失常发生率高达６４．７％。在５ｎｍｏｌ／ｋｇ时可明显增强肾上腺素（Ｅ）和去甲肾上腺素（ＮＥ）的致心律失常作用（未发表资料），而Ｅ也是升高血...     

不同剂量肾上腺素引起瞬时血压升高对血脑屏障开放的影响

目的：了解血压不同程度的瞬时升高对血脑屏障（ Ｂ Ｂ Ｂ）的影响。　方法：用不同剂量的肾上腺素（ Ａ Ｄ）对成年大鼠进行静脉注射，观察动脉血压的变化与 Ｂ Ｂ Ｂ开放程度之间的关系。结果：不同剂量 Ａ Ｄ 引起动脉压瞬时升高的幅度和变化时程与 Ｂ Ｂ Ｂ开放程度呈正相关趋势，当 ５ μｇ·ｋｇ－ １ Ａ Ｄ 注射后引起的动脉压在 ３６ ｓ 间一过性升高 ５０ｍ ｍ Ｈｇ 即可使 Ｂ Ｂ Ｂ轻度开放，而 ３μｇ·ｋｇ－ １ Ａ Ｄ 引起的血压升高则不能开放 Ｂ Ｂ Ｂ。　结论：一过性升高的动脉压在升幅和时程达到一定的阈值即可引起 Ｂ Ｂ Ｂ的开放。     

麻醉前肌注盐酸戊乙奎醚对老年人循环系统的影响

传统的抗胆碱药阿托品能抑制腺体分泌而广泛应用于麻醉前用药,但由于其抗M2受体作用,常引起心率加快,特别对老年人和心血管患者会产生不利影响.戊乙奎醚(成都力思特制药有限公司)是一种新型抗胆碱药,对M1、M3受体有高度选择性,而对M2受体无明显作用[1],理论上它可以避免阿托品的心血管作用.本文比较了戊乙奎醚和阿托品对老年人循环系统的影响,为盐酸戊乙奎醚的术前应用提供临床依据.     

β肾上腺素能受体激动剂对离体大鼠肺泡液体清除率的作用

目的探讨β1肾上腺素能受体激动剂地诺帕明、β2肾上腺素能受体激动剂特布他林、β3肾上腺素能受体激动剂BRL37344对离体大鼠肺泡液体清除率(AFC)的作用及机制。方法5%白蛋白等渗生理盐水溶液和不同药物混合后灌注到离体大鼠的肺泡腔内,根据灌注前及其孵育1h后白蛋白浓度的变化来计算大鼠AFC。结果基础AFC为6.9%±2.2%,地诺帕明、特布他林、BRL37344可显著提高AFC(分别为17.1%±2.4%、19.5%±1.2%、19.9%±2.5%)。β1肾上腺素能受体阻滞剂Atenolol可完全抑制地诺帕明提高AFC(6.1%±0.9%)的作用,但不能阻滞特布他林和BRL37344的作用。β2肾上腺素能受体阻滞剂ICI118551完全抑制了特布他林和BRL37344提高AFC(分别为5.7%±0.6%和7.8%±2.6%)的作用,部分抑制了地诺帕明的作用(AFC为12.7%±1.8%)。β3肾上腺素能受体阻滞剂SR59230A部分抑制了BRL37344和特布他林的作用(AFC分别为13.8%±3.1%和14.5%±3.4%),但不能阻滞地诺帕明的作用。结论地诺帕明、特布他林、BRL37344可以显著提高大鼠的AFC。但地诺帕明和特布他林是分别通过β1、β2肾上腺素能受体起作用;而BRL37344可能是通过β2肾上腺素能受体调节的。ICI118551和SR59230A可能分别具有抑制β1或β2肾上腺素能受体的作用。     

盐酸异丙肾上腺素在急性肺损伤早期的干预作用

目的 探讨肺表面活性物质(PS)系统在油酸性急性肺损伤(ALI)时变化的作用机制及β肾上腺素能受体激动剂的干预作用,为临床治疗ALI开辟新的治疗措施提供理论依据和实践方向.方法 30只SD大鼠随机分成3组(每组10只),即油酸致ALI组(OA组)、异丙肾上腺素治疗组(ISO组)和生理盐水对照组(NS组).观察4 h后测...     

异丙肾上腺素静滴后的反常作用

异丙肾上腺素是一种β受体激动剂，应用后对心脏有正性肌力、正性频率和正性传导的作用。临床用于治疗极缓慢性心律失常，给药后可使基本心率提高，传导阻滞程度减轻。除治疗心律失常外，心脏电生理检查中常用其促进诱发室上速和室速。绝大多数情况下，静注异丙肾上腺素后心率增快，心动过速容易诱发，但在极少数情况下，给药后出现反常作用，表现为心率减慢或传导阻滞，即异丙肾上腺素给药后表现为“负性频率”和“负性传导”的令人意外作用。     

去甲肾上腺素及其受体在痛性糖尿病神经病变中的作用

去甲肾上腺素(NE)作为中枢神经系统和交感神经系统中广泛分布的一种单胺类神经递质,其在疼痛方面的调节作用不容忽视.NE及其受体系统与痛性糖尿病神经病变的发生密切相关,外周NE递质受体系统主要起促痛作用,中枢NE递质受体系统则主要起镇痛作用,有关NE及其受体系统的研究对痛性糖尿病神经病变的防治有重要意义.     

肾上腺素能β受体在去甲肾上腺素引起的心肌细胞离子泵损害中的作用研究

本文报告以去甲肾上腺素(NE)50μg/kg由家兔耳静脉注射,2分钟后致死。取左心室肌制备膜微粒体,测Na~+/K~+-ATP酶及Ca~(2+)-ATP酶活性,过氧化脂质(LPO)含量;取心尖部肌肉匀浆后提取及测定cAMP含量。结果,NE明显抑制二酶活性,P均<0.001,明显增加LPO及cAMP含量,P均<0.001。在注射NE前2分钟自耳静脉注射α受体阻滞剂酚妥拉明1mg/kg,或β受体阻滞剂心得静60μg/kg,或二者合用。结果示β受体阻滞剂明显阻抑NE效应,P<0.001或0.05;而α受体阻滞剂未显示阻抑作用,P均>0.05。结果提示,β受体在介导NE效应中占优势。     

经支气管镜下局部灌注肾上腺素的安全性分析

目的 探讨支气管镜下滴注肾上腺素的安全性.方法 74例中男52例,女22例,年龄20～78岁,平均年龄(53.08±12.43)岁,分为3组:①对照组27例,术前常规阿托品0.5 mg肌肉注射,2％利多卡因表面麻醉.常规支气管镜检查及治疗.术中未使用肾上腺素.②大气道组32例,术前处理及支气管镜操作同对照组,但于术中向段以上支气管黏膜表面灌注1∶20 000肾上腺素溶液(2.28±1.49) ml.③小气道组15例,术前处理及支气管镜操作同对照组,于术中用2 mm导管嵌于末梢支气管并向远端推注1∶20 000肾上腺素溶液(2.88±1.94) ml.三组间术前(给药前)基本情况具有可比性:年龄、术前收缩压、舒张压及心率差异均无统计学意义,大气道组与小气道组肾上腺素溶液用量差异亦无统计学意义.对三组病例于支气管镜检查前后的观测指标进行以下分析:①检查前后收缩压、舒张压、心率变化(自身对照);②两两比较三组间检查前后收缩压差、舒张压差、心率差;③观察给予肾上腺素后其他相关不良反应的发生情况,包括心悸、胸闷、胸痛、苍白或潮红、头痛、肌肉震颤等.结果 ①术后收缩压、舒张压及心率均有不同程度的增加(P＜0.05或P＜0.01).②给药前后收缩压差:小气道组差值＞大气道组差值＞对照组差值,小气道组收缩压差与后两组间比较差异有统计学意义(P＜0.05),小气道组心率差与对照组比较差异有统计学意义(P＜0.05).其余组间差异均无统计学意义.各组舒张压差无显著差异.③大气道组及小气道组血压及心率变化均与肾上腺素用量无相关性(r2分别为0.008及0.18,P＞0.05).④小气道组有不同比例患者出现心悸、心绞痛(3例)、震颤、皮肤潮红或苍白等.结论 小气道内滴注肾上腺素可引起全身不良反应.     

褪黑素对异丙肾上腺素致小鼠急性心肌缺血的保护作用

目的观察褪黑素(MT)对异丙肾上腺素(Iso)所致小鼠急性心肌缺血损伤的保护作用。方法采用腹腔注射Iso(Iso 2 mg/kg)制备小鼠急性心肌缺血模型,观察不同剂量MT对小鼠心肌缺血损伤后Ⅱ导联心电图S-T段的偏移值、心肌含水量(MWC)、心肌指数(MI)、在常压缺氧条件下的存活时间。结果 MT能明显降低S-T段偏移值、MWC和MI,并且能延长小鼠心肌损伤后在常压缺氧下的存活时间。结论 MT对Iso所致小鼠急性心肌损伤具有保护作用。     

整夜完全睡眠剥夺对心血管自主神经活动的影响

目的为研究整夜完全睡眠剥夺对人心血管自主神经活动的影响。方法对18例健康青年男性进行了整夜完全睡眠剥夺。在睡眠剥夺前后采集心电图及桡动脉连续血压波形。并进行频谱分析和对各频谱成分进行标准化。心率变异(HRV)的高频(HF)代表心脏副交感神经调制,低频(LF)代表交感神经调制而低频与高频的比率(LF/HF)代表交感神经与副交感神经的平衡,血压变异(BPV)的LF代表血管交感神经调制。结果睡眠剥夺前后心率与血压无显著变化。与基础值相比,整夜睡眠剥夺后HRVLF显著增加[(67·0±13·9)%vs(59·4±15·7)%,P=0·039],HRVLF/HF也显著增加(3·8±2·3比2·7±1·7,P=0·032),HRVHF有显著降低[(22·8±10·4)%比(29·0±11·6)%,P=0·030];BPVLF有显著增加[(72·4±13·2)%比(63·2±16·5)%,P<0·001]。结论整夜完全睡眠剥夺可导致健康青年男性心血管交感神经调制增加以及心脏副交感神经调制降低。     

Microalbuminuria and cardiovascular risk factors in type 2 diabetes mellitus

Prospective studies have shown that increased urinary albumin excretion is a risk factor for cardiovascular morbidity and mortality in patients with Type 2 diabetes mellitus, but the nature of the association remains unknown. Eighty-five patients aged less than 65 years and not treated with insulin were studied. The overnight albumin excretion rate (AER) was measured in each patient and analysed in relation to several putative risk factors for cardiovascular disease. AER was used both as a continuous variable and after dividing patients into high-risk (AER greater than or equal to 10 micrograms min-1) and low-risk (AER less than 10 micrograms min-1) groups. By both methods of analysis AER was significantly correlated with both seated and supine diastolic blood pressure levels and with resting heart rate. Body mass index and waist-hip ratio appeared higher and HDL-cholesterol lower in the at-risk group, but differences were not statistically significant. The level of Factor VII was not significantly lower in the at-risk group. Little of the cardiovascular risk associated with raised AER can be attributed to associations with conventional risk factors.     

动脉导管未闭导管封堵与外科缝扎术对心率血压的影响

目的：观察动脉导管未闭（PDA）导管封堵与外科缝扎术对心率、血压的影响。方法：119例PDA患者中62例做外科缝扎手术，57例做Amplatzer封堵器封堵。观察术前、术后其心率、血压的变化情况。结果：（1）对心率的影响：手术组：术前、后有明显差异（P〈0．05）；介入组：术前、后没有明显差异（P〉0．05）。两组术前没有明显差异（P〉0．05），术后介入组心率明显低于手术组（P〈0．05）；（2）对血压影响：两组术前、后收缩压与舒张压均无显著性差异（P〉0．05）。两组间术前收缩压及舒张压无显著性差异（P〉0．05），但术后均出现显著性差异（P〈0.05）。结论：手术组术后心率增快比介入组明显。介入组术后收缩压和舒张压明显比手术组高。     

代谢综合征患者血压变异性和心率变异性的临床研究

目的 通过观察代谢综合征(MS)患者血压变异性(BPV)和心率变异性(HRV),探讨MS对心血管系统自主神经功能的影响.方法 入选MS患者(MS组)110例及对照组46例,分别进行24h动态血压和动态心电图监测,对比分析两组的BPV和HRV的指标.结果 (1)MS组的一般资料(性别比、年龄)及HDL-C与对照组比较,差异均无统计学意义(P＞0.05);MS组的体质指数(BMI)、腰围(WC)、腰臀比(WHR)、总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、空腹血糖(FBG)、体脂含量(FATc)及体脂比例(FATp)与对照组比较,差异均有统计学意义(P＜0.05).(2)MS组BPV中9项指标均较对照组显著性增高(P＜0.05);其余3项(dDBPSD、nSBPSD及nDBPSD)指标升高,但无统计学意义(P＞0.05).(3)MS组HRV各项指标与对照组比较,差异均有统计学意义(P＜0.05).(4)MS与性别、吸烟、心血管病早发家族史、高血压、糖尿病、TG、FBG及MBI具有相关性(P＜0.05);与饮酒、TC、HDL-C及LDL-C无相关性(P＞0.05).结论 MS患者存在心血管系统自主神经功能紊乱,表现为BPV的显著升高和HRV的显著降低,其与性别、吸烟、心血管病早发家族史、高血压病、糖尿病、TG、FBG及MBI相关.     

Effect of pacemaker rate-adaptation on 24 h beat-to-beat heart rate and blood pressure profiles.

AIMS: The aims of the study were to evaluate the 24-h beat-to-beat heart rate (RR) and blood pressure changes during closed loop stimulation (DDD-CLS) pacing and conventional fixed rate DDD pacing with respect to spontaneous activity. METHODS: We simultaneously and continuously measured beat-to-beat heart rate and blood pressure for 24 h in patients implanted with Inos2+ (Biotronik GmbH, Berlin, Germany). A randomised cross-over comparison of DDD-CLS and DDD pacing was performed by short- and long-term analyses. RESULTS: Seventeen patients (10 males, aged 46-85 years) were enroled in the study: 11 completed the protocol. The percentage of atrial stimulation was 72.87% during DDD-CLS and 38.36% in DDD (P=0.003). All patients were 100% stimulated in the ventricle. On average, the percentage increase of paced RR intervals with respect to spontaneous beats was only 7.4% in DDD-CLS but 20.1% in DDD (P=0.0001). A significant correlation between spontaneous and paced RR profiles was obtained only during DDD-CLS (r(DDD-CLS)=0.77, r(DDD)=0.23, P=0.01). Short-term analysis revealed a 3.79% reduction of the escape interval in DDD-CLS and 8.19% in DDD, and the relative fall in diastolic blood pressure was 1.14% in DDD-CLS and 3.81% in DDD. CONCLUSION: DDD-CLS provided physiological heart rate fluctuations throughout the 24-h test. The blood pressure profiles of paced and spontaneous beats were comparable. The onset of paced rhythm in DDD-CLS resulted in a less pronounced decrease in heart rate and fall in diastolic pressure than in DDD.     

健康老年人糖餐后血压心率变化

采用常规方法测量了20名74.95±4.73岁健康老年人糖餐前、后(试验组)及其中11例摄水前、后(对照组)动脉血压及心率。结果表明,受试者中18例(90%)糖餐后1小时内平均收缩压、舒张压均明显下降(P<0.001,P<0.001),心率显著加快(P<0.001),而摄水后无此变化。这提示老年人餐后困倦或晕厥与血压下降有关。     

不同阶段糖尿病肾病患者自主神经功能和昼夜血压、心率的变化

探讨自主神经功能和昼夜血压、心率在不同阶段糖尿病肾病患者中的变化。采用 2 4h动态心电图和血压同步监测 38例正常对照组和 84例糖尿病患者 ,包括A组 (正常蛋白尿 ) 4 8例、B组 (微量蛋白尿 ) 2 0例、C组 (大量蛋白尿组 ) 16例。结果 :A组糖尿病患者已有夜间血压和心率增高 ,昼夜血压、心率下降幅度及部分心率变异指标的降低 ;随蛋白尿增多 ,上述指标异常加重 ,并出现白昼血压和心率增高。A、B、C组分别有 5 4 .17%、75 .0 0 %和 87.5 0 %的患者出现昼夜血压节律消失 ,而对照组仅有 2 1.0 5 %。结论 :糖尿病患者普遍存在自主神经病变 ,夜间血压和心率增高可能就是糖尿病肾病早期的临床征象     

Mechanism of hypotensive transients associated with abrupt bradycardias in conscious rabbits

BACKGROUND: Transient bradycardic hypotensive events occur in resting rabbits. If the hypotension is due to vasodepression, these events may be a model for vasovagal syncope. OBJECTIVES: To determine whether these events are responses to brief stimuli and whether the hypotensive episodes are solely due to rapid-onset bradycardia. METHODS: Rabbits were instrumented with subcutaneous electrocardiogram leads, and cannulae were acutely inserted into an ear artery to obtain continuous arterial pressure measurements. Exposure to brief, low-level auditory stimuli at 5 kHz transiently increased the RR interval by approximately 70 ms and decreased mean arterial pressure by approximately 5 mmHg. RESULTS: These evoked bradycardic hypotensive events were almost identical to previously reported spontaneous bradycardic hypotensive events. Intra-aortic telemetric blood pressure monitoring was used to demonstrate that the evoked hypotension reflected prolonged diastole, rather than local ear arterial vasoconstriction. Furthermore, administration of the muscarinic blocker glycopyrrolate abolished not only bradycardia (RR interval 64+/-14 ms to 1+/-1 ms; P<0.0001), but also hypotension (--4.1+/-0.8 mmHg to --0.4+/-0.3 mmHg; P=0.0055). Finally, cardiac pacing abolished the inducible bradycardia (RR interval 51+/-10 ms to 2+/-1 ms; P=0.0006) and its associated hypotension (--4.1+/-0.7 mmHg to --1.2+/-0.3 mmHg; P=0.003). CONCLUSIONS: Brief auditory stimuli evoked a transient bradycardia mediated by cardiac muscarinic receptors and consequent hypotension. This is not a model for vasovagal syncope.     

倾斜试验对血管迷走性晕厥的诊断及分型

目的 探讨倾斜试验对血管迷走性晕厥的诊断及分型的意义。方法 ８０例不明原因晕厥患者为病人组,４７例无晕厥病史的健康人作为对照组均采用此试验,包括基础倾斜试验和异丙肾倾斜试验。结果 （１）不明是性主（７６．２５％）明显高于对照组（２９．７９％）,异丙肾滴注后,试验阳性率明显增加,假阳性率相应增加。（２）试验阳性者晕即刻民基础血压比较差异有显著性,而心率比较差异无显著性。（３）在所有试验阳性者中,血管     

A nation-wide cross-sectional study of urinary albumin excretion rate, arterial blood pressure and blood glucose control in Danish children with type 1 diabetes mellitus. Danish Study Group of Diabetes in Childhood

Nation-wide screening for microalbuminuria in Denmark was performed in 22 paediatric departments treating children with Type 1 diabetes. Over a period of 6 months 1020 children (less than or equal to 12 years) and adolescents (greater than 12 to 19 years) were screened (81% of total). Of these, 957 (94%) performed at least two timed overnight urine collections. In 209 non-diabetic subjects the upper 95% limit for normal albumin excretion rate (AER) was 20 micrograms min-1. Mean overnight AER was significantly (p less than 0.001) elevated in diabetic (3.0 x/divided by 2.3 (SD tolerance factor) micrograms min-1) and in non-diabetic (2.5 x/divided by 2.2 micrograms min-1) adolescents compared with diabetic (1.7 x/divided by 2.1 micrograms min-1) and non-diabetic (1.3 x/divided by 2.2 micrograms min-1) children. In the diabetic patients AER was positively correlated with the body surface area and age. Among the patients with Type 1 diabetes, 4.3% (18 males and 23 females) had AER greater than 20 to 150 micrograms min-1 (persistent microalbuminuria). A further 7 adolescents (0.7%) had overt proteinuria (greater than 150 micrograms min-1). Clinical data for the 41 diabetic patients with AER greater than 20 to 150 micrograms min-1 were compared with those for 569 diabetic adolescents with AER less than or equal to 20 micrograms min-1 and duration of diabetes more than 2 years. The group with AER greater than 20 to 150 micrograms min-1 had significantly higher mean age (16.5 years) than the group with AER less than or equal to 20 micrograms min-1 (15.0 years; p less than 0.001). Females with AER greater than 20 to 150 micrograms min-1 had significantly higher mean HbA1c level (10.8 +/- 1.9%) than those with AER less than or equal to 20 micrograms min-1 (9.8 +/- 1.9%, p less than 0.003); they also had impaired linear growth (standard deviation score -0.25 vs + 0.16; p = 0.003). These associations were not found in males. Mean body mass index (BMI) was significantly increased in both females (22.2 +/- 2.9 kg m-2) and males (20.8 +/- 2.7 kg m-2) with AER greater than 20 to 150 micrograms min-1, compared with diabetic patients with AER less than or equal to 20 micrograms min-1 (females 20.8 +/- 3.0 kg m-2, p = 0.02; males 19.7 +/- 2.4 kg m-2, p less than 0.006).(ABSTRACT TRUNCATED AT 400 WORDS)