Reversibility of increased formation of catecholamines in patients with alcoholic liver disease

Background: While chronic alcohol abuse has been shown to be associated with increased production of catecholamines, little is known about the reversibility of this increased sympathetic activity and the influence of severity of alcoholic liver disease (ALD). The aim of the present study was to investigate whether the increase in urinary excretion rates and plasma levels of catecholamines in alcohol‐abusing patients are reversible during prolonged abstinence, especially with respect to the severity of ALD. Methods: Urinary excretion rates and plasma levels of noradrenaline (NA), adrenaline (A) and dopamine (DA) were determined in 15 subjects with mild to moderate ALD (ALD1) and in 7 alcoholic cirrhotics (ALD2) on admission and after 2 and 12 weeks of abstinence. Eight healthy males, age‐matched to ALD1, served as controls (HC). Results: Urinary excretion rates (24?h) and resting plasma concentrations of NA and A were increased in ALD1 and ALD2 about 2‐fold, while those of DA were elevated only moderately compared to HC. During exercise under a load of 100 watts, the increases in plasma levels of NA and A with reference to the resting values were nearly identical in all three groups. Already after 2 weeks of abstinence, the urinary excretion rate of NA had nearly normalized in ALD1 but remained unchanged in ALD2. Conclusion: The marked enhancement of catecholamine production, especially that of NA, observed in actively drinking alcoholics is reversible under abstinence within a few weeks in subjects with mild to moderate ALD but only partially reversible in alcoholic cirrhosis.     

全麻复合硬膜外麻醉对胆囊切除术患者心血管应激的影响研究

目的探讨全身麻醉复合硬膜外麻醉对胆囊切除患者术中心血管应激反应的影响,为胆囊切除术中麻醉安全提供参考。方法82名胆囊切除术患者随机分为研究组及对照组,两组患者均采用全身麻醉,研究组复合硬膜外麻醉,比较两组患者麻醉过程及手术过程心血管反应的差异及血清肾上腺素及去甲肾上腺素水平变化。结果两组患者插管前心率（heartrate,HR）、平均动脉压（mean arterial pressure,MAP）无差异,插管后及拔管后研究组患者HR、MAP低于对照组,牵拉胆囊时研究组患者HR、MAP高于对照组。两组患者插管前及插管后血清肾上腺素及去甲肾上腺素水平无显著差异,牵拉胆囊后及拔管后研究组血清肾上腺素及去甲肾上腺素水平低于对照组。结论全麻复合硬膜外麻醉能够减轻胆囊切除患者心血管应激反应,增加麻醉安全,可能与其对植物神经反射通路的阻断作用有关。     

右美托咪啶对颈丛麻醉下甲状腺手术应激反应的影响

目的观察右美托咪啶对颈丛麻醉下甲状腺手术应激反应的影响。方法美国麻醉医师学会(ASA)分级Ⅰ~Ⅱ级择期在颈丛麻醉下行甲状腺手术的患者60例,随机分为对照组(Con组)和盐酸右美托咪啶组(Dex组),每组30例,两组分别于麻醉诱导前(T0)、拔管即刻(T1)、术后第1天清晨(T2)和术后第2天清晨(T3)抽取静脉血,测定血糖、去甲肾上腺素、肾上腺素水平。结果与同组T0时间点相比,Con组T1时间点的平均动脉压(MAP)和心率(HR)均显著升高(P值均<0.05),而Dex组在各时间点均无明显变化(P值均>0.05)。Dex组T1时间点的MAP和HR均显著低于Con组同时间点(P值均<0.05)。Con组T1、T2、T3时间点的血糖、去甲肾上腺素及肾上腺素水平均显著高于同组T0时间点及Dex组同时间点(P值均<0.05)。结论颈丛麻醉期间持续应用盐酸右美托咪啶有利于维持术中血流动力学平稳,有效降低行甲状腺手术患者的围术期血糖、去甲肾上腺素、肾上腺素水平,抑制围术期应激反应。     

阿替卡因联合肾上腺素治疗牙髓病临床价值评析

目的：探析阿替卡因联合肾上腺素治疗牙髓病的临床效果。方法选择2014年2月～2015年1月期间我院收治的牙髓病患者66例为研究对象，随机分为两组，其中给予对照组常规治疗，而观察组则运用阿替卡因与肾上腺素联合治疗，对比分析两组的治疗效果。结果两组均顺利完成治疗，观察组的麻醉起效时间为（133±22）s；而对照组的麻醉起效时间为（187±32）s，并且观察组的麻醉总有效率优于对照组，组间对比差异有统计学意义（P＜0.05）。结论临床上将阿替卡因和肾上腺素联合运用在牙髓病的治疗中，不仅起效快、安全性高，在一定程度上还能提高麻醉效果，确保手术的顺利进行。     

Changes in intracellular ion activities induced by adrenaline in human and rat skeletal muscle

To study the stimulating effect of adrenaline (ADR) on active Na⁺/K⁺ transport we used double-barrelled ion-sensitive micro-electrodes to measure the activities of extracellular K⁺ (aK_e) and intracellular Na⁺ (aNa_i) in isolated preparations of rat soleus muscle, normal human intercostal muscle and one case of hyperkalemic periodic paralysis (h.p.p.). In these preparations bath-application of ADR (10⁻⁶ M) resulted in a membrane hyperpolarization and transient decreasesaK_e andaNa_i which could be blocked by ouabain (3×10⁻⁴ M). In the h.p.p. muslce a continuous rise ofaNa_i induced by elevation ofaK_e to 5.2 mM could be stopped by ADR. In addition, the intracellular K⁺ activity (aK_i), the free intracellular Ca²⁺ concentration (pCa_i) and intracellular pH (pH_i) were monitored in rat soleus muscle. During ADRaK_i increased, pH_i remained constant and intracellular Ca²⁺ apparently decreased. In conclusion, our data show that ADR primarily stimulates the Na⁺/K⁺ pump in mammalian skeletal muscle. This stimulating action is not impaired in the h.p.p. muscle. Parts of the results have been presented to the German Physiological Society (Ballanyi and Grafe 1987)     

Die physiologische Variabilität der Plasma-Katecholamine

Summary In an earlier publication, we described a modified procedure for the determination of plasma catecholamine levels using high-performance liquid chromatography (HPLC), followed by amperometry. In this paper, we present our results on the variability of normal catecholamine values in plasma for noradrenaline (NA), adrenaline (A) and dopamine (DA). In 122 women and men at rest, the range for NA was 0.15–3.5 nmol/l, for A 0.01–0.8 nmol/l and for DA 0.04–4.5 nmol/l. We also describe the effects of orthostasis, intravenous catheters, food intake, cigarette smoking, age and sex on venous catecholamine levels. The efficiency of the HPLC method allowed us to check, using a large subject group, the results obtained by other authors from studies involving smaller subject groups with more expensive and time-consuming methods.

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Abkürzungen A Adrenalin - DA Dopamin - HPLC High Performance Liquid Chromatography - NA Noradrenalin     

Adrenaline inhibits muscarinic transmission in bullfrog sympathetic ganglia

The effect of adrenaline (Ad) on muscarinic transmission was examined in B neurones of bullfrog sympathetic ganglia by using intracellular and voltage-clamp recording methods. Bath-application of Ad (5–500 M) caused a depression of the slow excitatory postsynaptic potential (EPSP) elicited by repetitive stimulations of preganglionic nerve fibres in the presence of curare (30 M). Ad also depressed the muscarinic ACh potential induced by ionophoretic application of ACh directly to curarized sympathetic neurones in a concentration-dependent manner. Isoprenaline mimicked the effect of Ad in producing the inhibition of the muscarinic ACh potential. Propranolol antagonized the inhibitory action of Ad. Dibutyryl adenosine 3,5-monophosphate had no significant effect on the muscarinic ACh potential. Under voltage-clamp conditions, Ad caused an inward current associated with inhibition of the M-current (Brown and Adams 1980). Ad depressed the amplitude of slow postsynaptic currents produced by applications of ACh and muscarine. At a concentration of 100 M, Ad produced a 68±8% (n=12) depression of the amplitude of the muscarinic ACh current. The inhibition of muscarinic transmission induced by Ad is due to a direct suppression of the muscarinic current at the postsynaptic membrane in bullfrog sympathetic ganglia.