垂体后叶素对心肌单相动作电位的影响及机理

用保持家兔处于闭胸状态记录心外膜心肌单相动作电位(MAP)的技术,用22只健康家兔,研究垂体叶素(Pt)对MAP的影响并探讨其机理。结果表明,在清醒局麻动物和动物用3％戊巴比妥钠30mg.Kg~1.iv.后分别用Pt1U.Kg~(-1)和2U.Kg~1.i.v.,均出现同对照差异显著的心率减慢、MAP振幅和O相最     

心脏负荷、变力性干予和心肌缺血时对左室区域心肌节段张力的影响

心肌节段张力是心肌收缩功能评定的重要指标,我们采用弓型张力计固定在开胸麻醉犬的心肌表面。观察心脏不同机能状态和结扎LAD造成心肌缺血时心肌节段发展张力(DT)的影响:每组均用5只犬,实验结果如下: 1.增加前负荷:低分子右旋糖酐15ml/kg.iv后,LVEDP和动脉压均增加显著(P<0.05)。心率、DT由38.5±9.07增至48.18±15.9g,经统计(P>0.05)无明显差异。     

促甲状腺激素释放致激素(TRH)抗失血性休克心功能机理研究

促甲状腺素释放激素(TRH)能明显地改善失血性休克动物血流动力学指标,本文进一步研究TRH抗失血性休克心功能机理。一组(n=20)麻醉开胸兔,心尖插管至左心室,通过压力传感器接到心功能分析仪上,动脉放血40mmHg,维持1小时,iv TRH(2mg/kg)观察心肌收缩性能指标     

牛磺酸对大鼠异丙肾上腺素心肌损伤的保护作用

大鼠皮下注射异丙肾上腺素(40mg/kg/日)造成心肌损伤模型,发现心肌组织钙含量和心肌AGTⅡ水平显著增加,并伴有严重的心肌损伤。若同时注射牛磺酸(200mg/kg/日)或疏甲丙辅酸(1mg/kg/日)均可拮抗异丙肾上腺素引起的心肌钙增加及AGTⅡ水平升高,并可缓解心肌组织病理损伤。结果提示牛磺酸抑制心肌AGTⅡ可能是其拮抗异丙肾上腺素心肌损伤的重要机制之一。     

吡喹酮不同途径给药在大鼠体内药代动力学及自胆汁中的排泄

大鼠iv吡喹酮20mg/kg,血药浓度时间曲线符合二室开放模型。消除快,t(1/2)β=0.36±(SD)0.07h。im 10,20,40mg/kg或ig 100 mg/kg后,血药浓度达峰时间较快,但消除相与iv比却相对明显缓慢。MATim和MATig均大于MRTiv。ig的生物利用度为13.2％,有明显首过效应。im则吸收完全,当im 10和20 mg/kg时消除动力学呈线性关系,而当增至40mg/kg时,有呈非线性     

人参皂苷Rg2对犬急性心源性休克的治疗作用

目的：研究人参皂苷（Rg2）对急性心源性休克的治疗作用。方法：采用冠状动脉分支结扎法复制犬缺血性心源性休克模型,给予Rg2 0.5 mg/kg、1 mg/kg,生脉150 mg/kg,iv。观测药物对平均动脉压（MBP）、心输出量（Co）、总外周阻力（TPVR）、心外膜电图（EECG）、心肌梗塞范围（MIS）和血清心肌酶水平的影响。结果：Rg2能明显增加心源性休克犬MBP、Co;明显降低TPVR及心外膜电图ST段升高的总mV数（ε-ST）和ST段升高等于或大于2 mV的电极数（N-ST）;缩小MIS;减少血清磷酸肌酸激酶（CPK）、乳酸脱氢酶（LDH）和天冬氨酸转氨酶（AST）的活性。结论：Rg2对心源性休克犬缺血心肌有明显的保护作用,其作用优于生脉。     

小檗碱通过非α_2肾上腺素能受体途径减轻LPS诱导的心功能障碍

目的:观察小檗碱(Ber)预防内毒素血症小鼠心功能障碍的作用机制是否与其激活α2肾上腺素能受体有关,并探讨中性粒细胞在其中的作用。方法:将雄性BALB/c小鼠随机分为对照组(control)、脂多糖组(LPS)、小檗碱+LPS组(Ber+LPS)、α2肾上腺素能受体拮抗剂育亨宾+小檗碱+LPS组(Yohimbine+Ber+LPS)、育亨宾+LPS组(Yohimbine+LPS)、小檗碱组、育亨宾+小檗碱(Yohimbine+Ber)组和育亨宾(Yohimbine)组,分别用蒸馏水,小檗碱(50 mg/kg),育亨宾+小檗碱(2 mg/kg+50 mg/kg)或育亨宾(2 mg/kg)灌胃,每天1次,连续3d,第3 d灌胃后1 h,腹腔注射生理盐水或LPS(20 mg/kg)。观察注射LPS后12 h各组小鼠心肌组织结构的改变,用VisualSonies Vevo770TM高分辨小动物超声系统测定小鼠的心功能,并用Western blotting方法测定LPS注射后0.5 h心肌髓过氧化物酶(MPO)的含量。结果:LPS注射后12 h,LPS组小鼠心肌组织出现明显水肿。小檗碱、育亨宾、小檗碱+育亨宾组小鼠心肌的病理改变明显轻于LPS组。超声心动图检测显示,LPS组小鼠心输出量(CO)和每搏量(SV)均显著低于对照组、小檗碱、育亨宾、小檗碱+育亨宾组。腹腔注射LPS后0.5 h,LPS组心肌MPO的含量显著高于对照组,小檗碱、育亨宾+小檗碱组心肌MPO的水平显著低于LPS组,而育亨宾组心肌MPO的含量与LPS组没有显著差别。结论:小檗碱预处理能够减轻内毒素血症小鼠的心功能障碍,其作用机制与其激活α2肾上腺素能受体和抑制LPS引起的心肌中性粒细胞浸润无关,体内α2肾上腺素能受体激活可能在LPS引起的心功能障碍中发挥重要作用。     

八肽胆囊收缩素逆转内毒素休克大鼠心功能降低的实验研究

目的: 观察八肽胆囊收缩素(CCK-8)改善内毒素休克(ES)大鼠心功能的变化,探讨CCK-8抗ES的作用及机制。方法: 实验分对照组、脂多糖(LPS)组、CCK组及CCK+LPS组;监测左室内收缩压(LVP)、左室收缩与舒张期内压变化的最大速率、心率(HR)和平均动脉压(MAP)的动态变化;分别测定2h血清、心肌组织中超氧化物歧化酶(SOD)活性、丙二醛(MDA)和一氧化氮(NO)含量的变化。结果: 静脉注射CCK-8(40μg·kg^-1),引起短时间心率减慢,轻度MAP、LVP和±LVdp/dt_max上升;静脉注时LPS(8mg·kg^-1),引起HR生快后慢双向改变MAP、LVP和±LVdp/dt_max快速持续下降;整体预先注射CCK-8,可明显缓解ES大鼠HR的快速变化,逆转MAP、LVP和±LVdp/dt_max下降,但未恢复至正常水平。CCK-8可提高ES大鼠血清、心肌组织中SOD活性,降低MDA和NO含量。结论: CCK-8可引起短时间心率减慢、轻度MAP上升和心肌收缩力增强;预先应用CCK-8可以减轻ES大鼠心肌氧化损伤,减少NO合成,恢复心肌收缩力,逆转心功能降低及顽固性低血压,是其发挥抗ES的重要机制之一。     

海风藤黄酮乙对离体兔心的作用(摘要)

本实验按改进的Langendorff氏法做离体兔心灌流观察海风藤黄酮乙(以下简称黄酮乙)对冠脉阻力,冠脉流量,心率和心肌收缩力的作用。一、黄酮乙持继灌流对冠脉阻力、心肌收缩力和心率的影响在恒流灌注下,给药前冠脉阻力为42.3±2.1mmHg(平均数±标准误,下同)用每100ml含5mg黄酮乙的乐氏液灌流5分钟后为34.6±1.8mmHg,10分钟为34.9±1.6mmHg(P均<0.05)。但心率和心肌收缩力均无明显变化。     

白藜芦醇对脓毒血症所诱导大鼠心肌损伤的保护作用及其机制研究

目的以脓毒血症诱导大鼠心肌损伤模型为切入点,从血流动力学、抗炎和抗氧化等多方面研究白藜芦醇对心肌损伤大鼠的保护作用机制。方法采用随机数字表法将60只大鼠在脓毒血症诱导大鼠心肌损伤模型后随机分为6组,即空白组、模型组、氨苄青霉素钠组(150 mg/kg)、白藜芦醇高剂量组(400 mg/kg),白藜芦醇中剂量组(200 mg/kg)、白藜芦醇低剂量组(50 mg/kg),每组10只。术后12 h开始给药并记录各组大鼠血流动力学参数检测心功能;HE染色法检测大鼠心肌病理情况;ELISA检测大鼠血清TNF-α、IL-6水平,心肌组织中心肌酶(CK)、乳酸脱氢酶(LDH)、丙二醛(MDA)和超氧化物歧化酶(SOD)含量;Western blot法检测心肌组织中TGF-β1、TLR4和p65的表达。结果白藜芦醇中剂量组(200 mg/kg)与氨苄青霉素钠(150 mg/kg)疗效相当,可改善心脏血流动力学参数和心肌形态学变化,明显降低血清TNF-α、IL-6和心肌组织CK、LDH和MDA水平(P<0.01),而增加SOD水平(P<0.01),下调TGF-β1、TLR4和p65的表达蛋白表达。结论白藜芦醇对脓毒血症大鼠心肌损伤具有一定的治疗效果,其机制可能与其抗炎抗氧化抑制炎症信号通路相关。     

The reaction of dogs to stimuli of vascular tone at various intervals after hypophysectomy

Summary Chronic experiments were staged on hypophysectomized dogs. At various intervals following the operation (from 1–3 months to 2 years) a study was made of the blood pressure and its shifts due to the effect of adrenalin pituitrin, acute blood loss and after the action of these substances against the background of blood-letting. The blood pressure in dogs sinks appreciably after total hypophysectomy. Following partial hypophysectomy the blood pressure reduction was not as great or it even remained on the former level but became more labile. In total hypophysectomy the reaction to adrenalin was more pronounced than after partial hypophysectomy. This declined with the progress of time after the operation. The reaction of dogs to pituitrin was more marked after total hypophysectomy; no relation to the time lapse after the operation was noted. An acute blood loss caused a pronounced blood pressure reduction only in dogs subjected to total hypophysectomy during the first postoperative months; later this reaction became less marked. A more pronounced reaction occurred upon the administration of adrenalin or pituitrin to totally hypophysectomized dogs after blood-letting.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 55, No. 1, pp. 40–43, January 1963     

普鲁卡因与垂体后叶素治疗大咯血临床观察

目的:对比普鲁卡因与垂体后叶素治疗大咯血的止血效果和不良反应。方法:回顾性分析2006年3月到2011年2月间收治的36例普鲁卡因治疗的大咯血病人以及32例垂体后叶素治疗的大咯血病人。结果:普鲁卡因治疗和垂体后叶素治疗对病人的止血效果无统计学差异(P>0.05),但垂体后叶素治疗的不良反应明显高于普鲁卡因(P<0.05)。结论:在垂体后叶素不能使用时,普鲁卡因是治疗大咯血有效且安全的药物。     

支扩大咯血病人的心理状况及对止血治疗的影响

目的 :了解支气管扩张大咯血病人的心理状况 ,探讨心理因素对止血治疗的影响。方法 :采用SCL -90调查大咯血病人的心理状况 ,并分组治疗 ,比较治疗组与对照组止血效果 ,分析心理因素对临床止血治疗的影响。结果 :在两组 6 2例大咯血病人中 ,83 87%有焦虑情绪 ,6 6 13%呈恐惧反应。心理因素引起血压升高者占 32 2 6 % ,影响垂体后叶素使用者占 2 0 97%。咯血持续时间 :治疗组平均 5天 ,对照组 7天。结论 :支扩大咯血病人多有短期性心理反应 ,主要表现为焦虑及恐怖性倾向。心理因素可使血压升高 ,在血管破裂的基础上加重咯血 ,并使垂体后叶素使用受限 ,多方面均影响止血效果。故对大咯血病人在止血治疗的同时 ,应加强心理治疗 ,不仅有益于心身健康 ,且可缩短咯血时间     

Effect of chlorophyll-a, fluorouracil, and pituitrin on experimental acute pancreatitis.

Intraductal administration of enterokinase in rats produced hyperamylasemia and acute hemorrhagic pancreatitis. The experimental pancreatitis and hyperamylasemia could be prevented by the concomitant intraductal injection of fluorouracil, pituitrin, or chlorophyll-a. The clinical implication of the study is that these agents, if given intraductally, may be useful in the prevention of iatrogenic hyperamylasemia and acute pancreatitis that may occur after endoscopic retrograde pancreatocholangiography.     

A telemetric examination of cardiovascular function during the development of, and recovery from, opiate dependence in rats

Rats were subject to daily injections of morphine or saline and were then allowed to spontaneously withdraw from morphine for 4 days. Mean arterial blood pressure (MAP) and heart rate (HR) were recorded continuously, via radiotelemetry, during the development of, and recovery from, opiate dependence. Injections of morphine produced pronounced and prolonged increases in MAP and HR which increased as morphine dose increased. There were also significant increases in MAP during the 19-23 h period after each morphine injection indicating the presence of withdrawal. Spontaneous withdrawal from morphine was associated with a pronounced (20% increase from baseline) and prolonged (72 h) increase in MAP. MAP returned to baseline levels 72-96 h after last morphine exposure. These results show that intermittent injections of morphine, and spontaneous withdrawal from these injections, are associated with profound alterations in cardiovascular function and confirm the usefulness of radiotelemetry for studying opiate dependence.     

The influence of hormones of the posterior hypophyseal lobe on the stimulated thyroid gland

Summary When an excess of pituitrin P is given to male rats thyroid function is depressed although the hypophyseal thyrotropic hormone content remains normal. If 6-methylthiouracil and pituitrin P are given together the gland responds to the thiouracil in the normal way, although under these conditions there is no increase of hypophyseal thyrotropic function.Therefore pituitrin P must act directly on the thyroid parenchyma without the involvement of the thyrotropic hormone of the adenohypophysis.Presented by Active Member AMN SSSR A. V. Lebedinskii Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 56, No. 9, pp. 107–111, September, 1963     

How do homeless adults change their lives after completing an intensive job‐skills program? A prospective study

Among people experiencing homelessness, difficulty securing housing is often compounded by concurrent challenges including unemployment, chronic illness, criminal justice involvement, and victimization. The Moving Ahead Program (MAP) is a vocational rehabilitation program that seeks to help adults facing these challenges secure competitive employment. We prospectively studied how MAP graduates (N = 97) changed from the beginning of MAP to about 6 months after graduation. We observed a variety of positive outcomes in not just employment and housing but also health, substance use, and criminal justice involvement. However, these gains were not universal; for instance, participants were less likely to report positive outcomes at follow‐up if they started MAP with a serious mental illness, made relatively small gains in work skills, or did not seek mental health treatment during the 6 months after they completed MAP. These findings might encourage program staff to devote additional resources toward supporting at‐risk students.     

Effects of centrally administered losartan on deoxycorticosterone-salt hypertension rats

To investigate whether brain AT1 receptor stimulation contributes as a hypertensive mechanism to deoxycorticosterone acetate (DOCA)-salt hypertension, losartan (1 mg/4 microL) or artificial cerebrospinal fluid (aCSF) was injected into the lateral cerebral ventricle in conscious control uninephrectomized Wistar rats or rats with DOCA-salt for 2 or 4 weeks, and mean arterial pressure (MAP) and heart rates (HR) were recorded. In rats with DOCA-salt treatment, resting MAP increased to 144+/-6 mmHg after 2 weeks and to 170+/-5 mmHg after 4 weeks versus 115- 120 mmHg in controls. In rats with 2 week DOCA-salt treatment, MAP started declining at 4 hr after intracerebroventricular (icv) injection of losartan, and significant decreases in MAP were found at 18 and 24 hr. In rats with 4 week DOCA-salt treatment, MAP was significantly decreased at 4, 18 and 24 hr. In both groups MAP decreased to that of control rats. In control rats, icv losartan had no effect on MAP and HR. Icv aCSF did not significantly change MAP and HR in either DOCA-salt hypertensive rats or control rats. Normalization of MAP after icv administration of the AT1 receptor antagonist suggests a significant role for brain AT1 receptor stimulation in the development and maintenance of hypertension in the DOCA-salt hypertensive rat model.     

Acute, subacute and chronic effect of cyclosporin-A on mean arterial pressure of rats with severe spinal cord contusion

Cyclosporin-A (CsA) protects and regenerates the neural tissue after spinal cord (SC) injury. These beneficial effects are achieved when CsA is administered at a dose of 2.5mg/kg/12h during the first 2 days after lesion. In view of these observations, it is realistic to envision that, CsA could be tested in SC-clinical trials. Since CsA is a drug strongly related to hypertension, results imperative to evaluate experimentally the effect of the above CsA-dose regimen on blood pressure. For this purpose, one hundred and twenty adult rats were subjected (10 groups) or not (10 groups) to SC-injury. Five injured and five Sham-operated groups received CsA. The remaining groups received only vehicle. Mean arterial pressure (MAP) was recorded from these animals at acute (6 and 24h post surgery; p.s.), subacute (96h), or chronic (30 days) stages of injury. In the latter, the therapy (CsA or vehicle) was administered only during the first 2 days p.s. or daily during 30 days of follow-up. The results of this study showed that SC-injury by itself induces a significant decrease of MAP during the acute and subacute phases of injury. CsA therapy was able to reestablish MAP parameters to control values in these phases. Regardless the therapy, a reestablishment of MAP was observed in chronic stages. Only the daily administration of CsA induced a significant increase in MAP, however; such variation remained into the normal ranges of MAP for rats. The potential benefits offered by CsA support its usefulness after SC-injury.     

The mechanism of the central action of hypertensin and pituitrin

Summary The electric activity of the cortical and subcortical formations of the brain in curarized cats was compared with the blood pressure level during the action of hypertensin and pituitrin prior to and after the prebulbar section of the brain. Prebulbar section of the brain eliminates the EEG changes occurring in the intact brain in the form of spindle shape impulse discharges, caused by the administration of these substances. It is supposed that this is due to the elimination of afferent impulsation from the pressoreception as a result of prebulbar section. Administration of hypertensin and pituitrin to animals with prebulbar division of the brain caused the appearance of high-frequency and low-amplitude biopotentials in the EEG. Evidently this was due to direct action of these substances on cerebral structures.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 54, No. 8, pp. 34–37, August, 1962