Cardiovascular effects of microinjections of angiotensin II into the nucleus tractus solitarii

The role of the angiotensin II system within the nucleus tractus solitarii (NTS) in central cardiovascular control was investigated by local microinjections of angiotensin II and the angiotensin II receptor antagonist saralasin. Microinjections of 1 ng angiotensin II into the NTS resulted in a monophasic depressor response (-7.3 +/- 1.7 mm Hg), while higher doses were characterized by a biphasic response, with an initial decrease followed by a subsequent increase in blood pressure (10 ng: -4.7 +/- 1.3/+7.9 +/- 1.1 and 100 ng: -2.4 +/- 1.2/+7.5 +/- 1.2 mm Hg). Heart rate decreased significantly following microinjections of 1 and 10 ng angiotensin II (-27 +/- 5.0 and -15 +/- 5.9 bpm), while with 100 ng angiotensin II there was no significant effect on heart rate. Prior i.v. administration of atropine (1 mg/kg) abolished the bradycardia, but did not significantly affect the blood pressure response. Microinjections of saralasin into the NTS elicited a dose-dependent pressor response (10 ng: 6.0 +/- 1.5 mm Hg; 100 ng: 16.8 +/- 3.4 mm Hg) and tachycardia (10 ng: 5 +/- 3.2 bpm; 100 ng: 17 +/- 4.4 bpm). Our data support the hypothesis that angiotensin II acts on specific receptors within the NTS to modulate peripheral cardiovascular responses. The cardiovascular effects elicited by microinjections of the peptide exhibit complicated dose-response relationships. The effects on heart rate, but not on blood pressure, appear to be mediated by parasympathetic activation.     

A Study on Hypotensive Action of Total Saponin of Ziziphus Jujuba Mill and Its Mechanism

Total saponin of Ziziphus Jujuba Mill seeds(ZS) produced amarked hvpotensive effect in anesthetized Sprague-Dawley rats(I. V. or I. P. )and cats (I. V. ). ZS showed no effect on the pressor effect of nor-adrenalinein rats. the depressor effect of ZS was not influenced by atropine nor bydiphenhydramine. ZS markedly inhibited the pressor reflex in catsinduced by ocelusion of the common carotid artery. In rats, ZS inhibitedthe spontaneous discharges of the preganglionic fibers of the greatersplanchnic nerve and decreased the plasma renin activity. These resultsshowed that the hypotensive action of ZS was probably central in origin.     

阿丹三滴眼液的质量控制

目的 :建立阿丹三滴眼液的质量标准。方法 :采用薄层层析法和高效液相色谱法对丹参和三磷酸腺苷分别进行定性分析 ,用可见分光光度法对硫酸阿托品进行定量分析。结果 :平均回收率为99 9 % ,RSD为2 46 % (n=5)。结论 :本方法简便、准确、专属性强 ,可用于阿丹三滴眼液的质量控制     

侧脑室内注射神经降压素所致降压反应机制的初步探讨

目的 研究大鼠侧脑室内注射（ｉｃｖ）神经降压素（ＮＴ）所致降压反应的中枢机制。方法 用乌拉坦麻醉雄性ＳＤ大鼠（３０只），将ＮＴ ｉｃｖ，观察其血压（ＢＰ）和心率（ＨＲ）的变化。然后分别ｉｃｖ Ｍ受体阻断剂硫酸阿托品和切断两侧颈部迷走神经，再ｉｃｖ ＮＴ，观察ＢＰＴ和ＨＲ的变化。结果 ｉｃｖ ＮＴ（１０μｇ／鼠）可引起ＢＰ升高或降低，ＨＲ减慢。预先ｉｃｖ阿托品２．５μｇ，可阻断ＮＴ的中枢降压反应；切     

Effect of cholinergic agonists and antagonists on gallbladder volume in fasting man

Summary The effect of direct cholinergic stimulation and blockade on gallbladder volume, determined by real-time ultrasonography (RUS), was evaluated in twenty normal, fasting subjects. Eleven subjects received atropine sulphate or placebo and 9 subjects a series of 3 injection of prostigmine, bethanechol or placebo, randomly assigned, at intervals of 24 h.RUS was performed under basal conditions after fasting for 12 h and every 5 min after drug injection up to 45 min in the atropine study and up to 60 min after prostigmine and bethanechol.There was no significant variation from fasting gallbladder volume after placebo in either group. After atropine sulphate gallbladder volume at first decreased and then significantly increased. With bethanechol and prostigmine, the volume fell significantly to a trough after 30 to 35 min, and then it returned to the basal value within 60 min. It is suggested that cholinergic mediation is involved in maintaining fasting tone in the gallbladder and that cholinergic stimulation causes contraction of the gallbladder by a direct effect.     

胆碱酯酶抑制剂中毒时血浆内毒素浓度变化的规律及宾赛克嗪的干预作用

目的 观察新型抗毒剂宾赛克嗪对维埃克斯染毒后不同时间点小鼠血浆内毒素浓度变化的影响及其机制.方法 306只雄性昆明小鼠被随机分为正常对照组、维埃克斯染毒模型组以及宾赛克嗪、阿托品和山莨菪碱3个治疗组;各治疗组分别于皮下注射维埃克斯0.02 mg/kg染毒前10 min经腹腔注射相应药物.各组均于染毒后1.5、3、6、24、48和72 h取血,检测血浆内毒素浓度.结果 与正常对照组[内毒素浓度为(1.90±0.41)kEU/L]比较,模型组1.5 h血浆内毒素浓度为(5.36±1.62)kEU/L,升高了约2倍;之后逐渐升高,至24 h达高峰,浓度为(11.47±3.90)kEU/L,较正常对照组升高了约5倍(P均<0.01),异常增高可持续至48 h,72 h后恢复至正常对照组水平.宾赛克嗪治疗组在1.5 h和3 h时内毒素浓度分别为(3.73±0.71)kEU/L和(3.95±1.26)kEU/L,显著低于模型组(p<0.01和P<0.05);6 h和24 h血浆内毒素浓度分别为(8.77±1.85)kEU/L和(11.47±2.51)kEU/L,与模型组比较差异无统计学意义,但显著高于正常对照组(P均<0.01);至48 h恢复至正常对照组水平.在相同实验条件下,阿托品治疗组血浆内毒素浓度在1.5～24 h显著高于模型组(P<0.05或P<0.01);而山莨菪碱治疗组血浆内毒素浓度在6 h达高峰,显著高于模型组(P<0.01).结论 维埃克斯染毒后1.5～48 h小鼠血浆内毒素浓度显著增高,使用宾赛克嗪能减轻胃肠道黏膜屏障功能的损伤,延缓内毒素进入血中的速度,并能缩短内毒素在血中的停留时间.而使用阿托品和山莨菪碱后则能加重胃肠道黏膜屏障功能的损伤.     

Atropine-Induced Multilevel Block in Acute Inferior Myocardial Infarction A Possible Indication for Prophylactic Pacing

The degree of A-V block increased after intravenous administration of atropine in 10 nondigitalized patients with acute inferior myocardial infarction who had narrow QRS complexes during periods of 1:1 A-V conduction. Short episodes of 3:1, 4:1 and 5:1 A-V block were seen to emerge: (a) in 6 patients, directly from Wenckebach periods; (b) in 3 patients, from alternating Wenckebach periods; and (c) in 1 patient, from a 3:2 Wenckebach period which led to a short-lived alternating Wenckebach period. Apparently, the predominance of the chronotropic effects on the sinus node over the dromotropic effects on the A-V node led to a tachycardia-dependent (more ischemic than vagal) process, exposing or producing multi- (two, three or four) level block involving the A-V node (and perhaps the His bundle). Subsequently, therapeutic pacing was instituted in 9/10 patients because they developed spontaneous symptomatic advanced A-V block. Therefore, it is possible that the early effects of atropine identified a narrowly-defined subset of patients in whom prophylactic pacing may be indicated. However, more studies are necessary to corroborate these assumptions.     

Ultrasound follow-up of infantile hypertrophic pyloric stenosis (IHPS) during conservative therapy: ultrasound findings as criteria for diagnosis and cure

Purpose  During conservative therapy of infantile hypertrophic pyloric stenosis (IHPS) with atropine sulfate, there are many patients who do not achieve normal values of pyloric wall thickness and canal length even though they are clinically cured (vomiting has ceased); an objective criterion for cure has not yet been established. The aim of this study was to examine whether the appearance of pyloric wall stratification can be used as a criterion for cure. Methods  Twenty infants with IHPS who were treated conservatively were enrolled. Two of them ultimately required surgery. Ultrasound examinations were done serially and the pyloric wall thickness and canal length were measured. The echogenicity of the pyloric wall and the presence of wall stratification were noted. Results  On admission, all infants satisfied the ultrasound criteria for IHPS and had a heterogeneous pyloric wall without stratification. With conservative therapy, symptoms disappeared, the pyloric wall thickness and the canal length gradually decreased, the echogenicity gradually became homogeneous and hypoechoic, and wall stratification appeared (in most cases before the pyloric wall thickness and the canal length had normalized). The absence of wall stratification suggests that cellular interstitial changes, such as edema or inflammation, are present in the pyloric wall in the acute stage. Conclusion  Pyloric wall stratification was absent during the acute stage, but it appeared after initiation of treatment but before the pyloric wall thickness and the canal length had normalized. The presence of pyloric wall stratification can be used as a criterion for cure; the absence of wall stratification can be added to ultrasound diagnostic criteria for IHPS.     

急性有机磷农药中毒阿托品用量与体温关系的临床研究

目的:探讨救治急性有机磷农药中毒中阿托品用量与患者体温的关系,指导临床阿托品用量。方法:根据患者阿托品化时体温把病人分为正常体温组(≤37.3℃)、低热组(37.4~38.0℃)、中热组(38.1~39.0℃)及高热组(≥39.1℃),将各组中的阿托品用量,体温进行比较,了解阿托品治疗效果。结果:在中热及高热组中阿托品用量偏大,有中毒表现,低热组中阿托品用量适当,正常体温组则偏小。结论:在救治急性有机磷农药中毒时,阿托品的用量使患者体温维持在37.4~38.0℃时,可以达到最好的治疗效果。