ADMA对交感神经损毁自发性高血压大鼠血压和肾功能的作用

目的:探讨不对称二甲基精氨酸(ADMA)对交感神经损毁自发性高血压大鼠(SHR)血压和肾功能的作用。方法:新生雄性SHR随机分成交感神经损毁组和对照组,采用单硫酸胍乙啶损毁新生SHR的交感神经。12周后测量常温下鼠尾血压;代谢笼法收集大鼠尿液,检测去甲肾上腺素(NE)排泄量;高效液相色谱法检测肾脏NE和ADMA含量;比色法检测大鼠肾脏一氧化氮(NO)含量;Western blot法测定内皮型一氧化氮合酶(e NOS)的表达;通过检测肾小球滤过率(GFR)评价肾脏功能。结果:与对照组相比,交感神经损毁组尿NE排泄量以及肾脏NE和ADMA含量均明显降低,肾脏NO含量和e NOS表达显著升高,收缩压和舒张压明显降低(P0.05),24 h尿微量白蛋白、尿钠量和GFR未见明显差异。结论:抑制交感神经系统可引起ADMA和NE释放减少,NO合成和e NOS表达升高,从而对血压产生调节作用;但交感神经系统对ADMA生成的调控并不是通过影响肾脏功能来实现的。     

阻断交感神经对小鼠小肠黏膜免疫相关细胞的影响

目的研究交感神经对肠道黏膜屏障的调节作用。方法采用常规组织学和免疫组织化学技术,观察经腹腔注射交感神经损毁剂6-羟多巴胺后小鼠小肠上皮内淋巴细胞、杯状细胞、IgA+浆细胞、肥大细胞的数量分布变化。结果注射6-羟多巴胺组小鼠与对照组小鼠相比,小肠各肠段的上皮内淋巴细胞减少了5.6%～33.8%,杯状细胞减少了10.6%～18.5%,两组指标在十二指肠之间和回肠之间差异极显著(P<0.01);肥大细胞增加了15.0%～57.1%,在空肠之间差异极显著(P<0.01);IgA+浆细胞增加了13.9%～61.4%,在十二指肠之间差异显著(P<0.05)。结论交感神经对调节小鼠肠道的免疫学屏障有着重要作用。     

川芎嗪对牛磺酸引起的交感神经节细胞膜电位变化的影响

实验中将牛磺酸（以任氏液为溶剂配成所需浓度的溶液）按一定时间间隔滴加到含有牛蛙椎旁交感神经节的灌流槽中，以引起交感神经节较为恒定的膜电位反应。采用细胞外微电极技术，记录离体灌流的牛蛙椎旁交感神经节细胞膜电位，观察川芎嗪对牛磺酸介导反应的抑制作用。牛磺酸（10mmol/L)可引起神经节细胞膜超极化（n=38)、去极化（n-14)以及去极化之后伴随超极化过程的双相反应（n=8)、GABAA受体拮抗剂荷包牡丹碱（500μmol/L）可抑制牛磺酸（10mmol/L)的超极化反应（n=6)。无钙溶液灌流对牛磺酸（10mmol/L)介导的反应无影响。川芎嗪 （300μmol/L）可抑制牛磺酸（10mmol/L)的超极化反应（n=13)、去极化反应（n=6)和双相反应（n=4)。结果表明川芎嗪对牛蛙椎旁交感神经节牛磺酸介导的膜电位变化有抑制作用。     

钙摄入量对SHR和WKY血压的影响

本文用高钙(2.81%或2.20%),中钙(0.5%)和低钙(0.12%)观察对自发性高血压大鼠(SHR)和正常血压大鼠(WKY)血压的影响。结果表明:高钙摄入大鼠的24小时尿总钙和血清总钙均明显高于中钙和低钙摄入大鼠;高钙摄入显著降低SHR的血压(P<0.01),同时也明显减缓SHR体重的增长,尤其是雌性SHR体重影响更明显;而低钙摄入则明显升高SHR的血压(P<0.001)。提示高钙摄入的降血压作用可能是对机体的一种非生理性效应。     

发光二极管红光照射对家兔血压影响的研究

目的应用发光二极管(LED)红光照射家兔颈部的交感神经,观察其对家兔血压的影响。方法日本大耳白家兔24只,雌雄各半,体质量2.0～2.5 kg。将实验家兔随机分为4组,每组6只:A组为正常对照组,B组为正常家兔红光照射组,C组为急性低血压模型对照组,D组为急性低血压模型红光照射组。应用LED红色光源分别照射B、D组40 min,A、C组不做红光照射处理,观察记录各组血压变化和神经放电变化情况。结果造模手术后30 min时C组血压与D组间差异无统计学意义(P>0.05),但均显著低于A组和B组。手术后70 min时D组血压显著高于C组,B组一直未见明显变化,说明LED红光照射对低血压家兔收缩压、舒张压均有升压作用,而对正常家兔血压无明显影响。结论应用LED红光照射家兔交感神经,使交感神经放电频率加快、幅度增大,急性低血压模型家兔血压恢复正常水平。LED红光照射对正常家兔的血压无明显影响。     

心房提取液对家兔尿量和动脉血压的影响

本文采用膀胱内插管收集尿量法和直接测压法,观察了心房提取液对家兔尿量和动脉血压的影响。结果表明,静脉注射心房提取液引起家兔尿量增加,动脉血压下降。与对照组比较,有显著差异(P<0.01,P<0.05)。揭示心房提取液有明显的利尿和降压作用。     

高压氧治疗对血压的影响

观察了40例患者(5例合并高血压)在一个疗程中每次入舱前及出舱后血压的变化。结果显示一疗程中血压发生的改变以升高次数为多(P<0.001)。分别超过15％和12％人次的血压升高的幅度≥2KPa和下降幅度≥1KPa。患者合并高血压与否,其血压改变值的均数是一致的(P>0.05)。结果支持高血压病人应将血压控制在21.33/13.3KPa以下才予入舱的建议,并提示应注意观察低血压者的血压情况。     

丙烷盐酸盐对自发性高血压大鼠和正常血压大鼠心肌跨膜电活动的影响

目的与方法:采用细胞内玻璃微电极技术,研究1-(2,6-二甲基苯氧基)-2-(3,4-二甲氧基苯乙氨基)丙烷盐酸盐(DDPH)对自发性高血压大鼠(spontaneously hypertensive rat, SHR)与正常血压大鼠(Wistar)离体左心室乳头状肌和左心房肌细胞跨膜电位的影响.结果:①给药前,SHR大鼠心室肌细胞动作电位复极50%(APD50)和90%(APD90)时程明显较正常血压大鼠延长.②DDPH(5～50 μmol·L-1)呈浓度依赖性抑制SHR左心室细胞Vmax降低动作电位振幅(APA),延长APD90和APD50,并可明显抑制右心房自发性电活动的频率,但对静息膜电位(RP)无明显的作用.对正常血压大鼠,DDPH呈类似的作用.结论:在相同的浓度作用下,DDPH抑制SHR左心室肌细胞Vmax与右心房自发性电活动的频率作用较正常血压大鼠显著,在SHR左心房肌细胞,DDPH(50μmol·L-1)延长APD50的作用较正常血压大鼠显著,对Vmax、APA和APD90作用两种大鼠无明显的差别.     

The effects of avoidance and conflict schedules on the blood pressure and heart rate of rats

Two studies examined the cardiovascular response to aversive conditioning as a function of the degree of control over the stressor. Experiment 1 used 24 normotensive rats assigned to 3 groups: experimental, yoked, and non-shock restraint control. Triplets of rats were exposed to signalled avoidance for 3 weeks. Experimental animals were required to turn a wheel to avoid shocks to themselves and their yoked partners. Direct cardiovascular monitoring via aortic catheters during the final avoidance session revealed that both systolic and diastolic blood pressure (BP) increased significantly in experimental and yoked rats during avoidance but remained elevated throughout avoidance and post-avoidance only in the yoked animals. Experimental rats also exhibited a significant increase in HR during early avoidance. Experiment 2 assessed the cardiovascular response to a reduction in the controllability of the stressor by exposing 24 rats, assigned to groups as above, to 11 weeks of conflict and avoidance conditioning. Indirect systolic BP was significantly higher in experimental and yoked rats as compared to controls when averaged over the 11 weeks of stress. Experimental and yoked rats also had significantly more hypertensive systolic BP readings (SBP≥150 mm Hg), 34% and 38% respectively, than controls (13%). Direct cardiovascular monitoring during a final conflict session showed sustained increases in systolic and diastolic BP during conflict and post-conflict for both experimental and yoked rats, attaining significance, however, only in the yoked group. These studies suggest that the opportunity to cope moderates the systolic BP response to aversive stimulation and the loss or lack of such opportunity leads to a significant increase in the number of hypertensive blood pressure readings.     

“一肾一夹”高血压鼠血清及组织内哇巴因含量及其与血压相关性的研究

目的:探讨内源性哇巴因(EO)在“一肾一夹(1k1c)”高血压模型血压升高中的作用及其分泌特点。方法:采用酶联免疫吸附试验(ELISA)测定“1k1c”高血压大鼠血清及多种组织内EO含量的改变,并对体内EO含量与大鼠血压进行相关性分析。结果:“1k1c”高血压鼠血清及心脏、肾脏、肾上腺、垂体及下丘脑内EO含量均高于正常大鼠;尤以肾上腺及下丘脑内EO含量最高;其中血清、肾脏及下丘脑内EO含量与大鼠血压呈显著正相关。结论:EO含量增加可能在“1k1c”模型高血压的发生机制中发挥着较为重要的作用;肾上腺可能是EO的来源之一。     

Changes in central artery blood pressure and wave reflection during a cold pressor test in young adults

The relative contribution of sympathetic nervous system (SNS)-induced increase in peripheral vascular resistance on central artery blood pressure (BP) and aortic wave reflection (augmentation index; AIx) is not completely understood. Central BP and wave reflection characteristics were measured using radial artery applanation tonometry before, during a 3-min cold pressor test (CPT), and 90 and 180-s post-CPT in 15 young, healthy adults (25 +/- 1 years). The CPT resulted in a greater magnitude of change in the estimated aortic systolic (31 vs. 23%, P < 0.05) and pulse (31 vs. 13%, P < 0.05) BP compared with the change in brachial artery BP. Additionally, the CPT resulted in an increased mean arterial pressure (MAP) (P < 0.05) and AIx (10 +/- 2 vs. 26 +/- 2%, P < 0.05). The change in MAP during the CPT was correlated to the change in AIx (r = 0.73, P < 0.01) and inversely related to roundtrip duration of the reflected wave to the periphery and back (r = -0.57, P < 0.05). The present study suggests that cold pressor testing results in a significant increase in arterial wave reflection intensity, possibly due to an increased MAP. However, the greater increase in systolic and pulse BP in the central compared with the peripheral circulation suggests that increased central artery wave reflection intensity contributes to increased left ventricular myocardial oxygen demand during CPT-induced hypertension.     

微元素粉末对大鼠血管内皮和平滑肌细胞膜电位的影响

目的:探讨微元素粉末(由铝、钛、硅等元素组成的超细粉末,粉末直径在0.5μm以下,microelementpowder,MP)对大鼠血管内皮和平滑肌膜电位的影响,探讨其改善微循环的机理。方法:培养大鼠肺血管内皮细胞和主动脉平滑肌细胞,用电位敏感的荧光探针和激光共聚焦显微镜测定细胞膜电位动态变化。结果:MP使平滑肌细胞显著超极化。ATP敏感钾通道(ATPsensitiveK⁺channel,K_ATP)阻滞剂优降糖(2μmol/L)对平滑肌膜电位无明显影响,但能完全逆转MP对平滑肌的超极化作用;MP使血管内皮细胞轻度超极化,其作用不受优降糖影响。结论:MP激活血管平滑肌K_ATP通道,使细胞膜超极化,从而扩张微血管和改善微循环。     

虎杖甙对正常人血管平滑肌细胞内钙和膜电位的调节作用

目的和方法：观察虎杖甙（ＰＤ）对人脐带动脉平滑肌细胞（ＶＳＭＣ）内游离钙、细胞膜电位的变化,以探讨ＰＤ对血管平滑肌的调节机制。用Ｆｌｕｏ－３－ＡＭ、ＤｉＢＡＣ４（３）标记培养的ＶＳＭＣ,在激光共聚焦显微镜上测定细胞内游离钙和膜电位变化。结果：给ＰＤ（０５ｍｍｏｌ／Ｌ）１０ｍｉｎ后,ＶＳＭＣ内游离钙浓度升高５６％±５６％。当ＰＤ加入前用维拉帕米和ＥＧＴＡ预处理后,则游离钙不再升高;ＥＧＴＡ和肝素预处理也抑制ＰＤ的升钙作用,而ＥＧＴＡ和普鲁卡因预处理则使细胞内钙显著升高。ＰＤ还可使ＶＳＭＣ膜电位去极化,加入钠通道阻断剂河豚毒素（２５μｍｏｌ／Ｌ）可完全阻断ＰＤ的去极化作用：加甲氰咪胍、维拉帕米、优降糖和利及丁预处理不能阻断ＰＤ去极化作用。结论：：ＰＤ可通过细胞外钙内流来增加细胞内游离钙浓度,并促进细胞外钠离子内流而导致细胞去极化     

Systemic overperfusion and resting blood pressure

During psychosocial stressors, individuals with mildly elevated resting blood pressures (BP) exhibit cardiac output (CO) that is in excess of metabolic demand (i.e., systemic overperfusion). The present study used the "additional" CO method to assess whether individuals in the high average BP range also exhibit systemic overperfusion at rest. Healthy young adult males (N = 48), divided into "high average" and "low average" groups using resting BP, participated in an active coping task. Consistent with past research, the high average group evidenced higher levels of additional CO than did the low average group during both baseline and task periods. More importantly, the high average group also exhibited significant amounts of additional CO at rest, whereas the low average group did not. These results may help to advance our understanding of the process by which systemic overperfusion may contribute to the development of elevated BP.     

Effect of impulse noise on water consumption and blood pressure in the female rat

Our laboratory has previously measured significant elevations in plasma angiotensin II concentrations accompanying brief intense noise exposures in rodents. The present investigation was designed to evaluate the effects of noise induced elevations in water consumption and blood pressure in normotensive female rats. The durations of noise exposure simulated an industrial setting in which impulse noise is present. The results indicate significantly increased blood pressure and water consumption with two weeks of noise exposure compared to shorter exposure durations.     

Effect of exercise on blood pressure in rats with chronic NOS inhibition

Regular training lowers blood pressure in hypertensive humans and other animals. We investigated the response to 4 weeks of treadmill exercise training in hypertensive male Wistar rats receiving the nitric oxide synthase inhibitor N ^ω-nitro-L-arginine methyl ester (L-NAME). The rats were on either a short- (4 weeks) or long-term (10 weeks) L-NAME treatment protocol and were subjected to running exercise that started concomitantly in the short-term group and in the 6th week in the long-term group. Four weeks of exercise training induced a fall in mean arterial pressure in both the short- [mean (SEM) 137.6 (4.0) mmHg] and long-term hypertensive groups [161.4 (2.3) mmHg] compared to their sedentary hypertensive controls [160.4 (3.3) mmHg and 176.8 (8.9) mmHg, respectively]. Exercise also increased muscle nitric oxide synthase activity in both of the trained hypertensive groups. Muscle nitrite levels were higher in the exercising short-term hypertensive group compared to both the sedentary control and the sedentary hypertensive groups, and were not different between the sedentary and exercising long-term hypertensive groups. Increased wall thickness of the aortic and mesenteric vessels was observed in the hypertensive groups, but was prevented in the exercising long-term hypertensive group. In rat, exercise reduces the elevated blood pressure in L-NAME-induced hypertension via increasing nitric oxide synthase activity. Changes in vessel structure with exercise training may also be involved in the blood-pressure-lowering effects. Electronic Publication