血浆清蛋白胆碱酯酶及前白蛋白检测在肝病诊治中的临床意义

目的:通过测定血浆清蛋白(A lb)、胆碱酯酶(Che)、及前白蛋白(PA)的水平变化,用于了解各种肝病的性质、转归和判断预后。方法:血浆清蛋白(A lb)为终点法、胆碱酯酶(Che)为酶动力学法、及前白蛋白(PA)免疫投射比浊法。结果:急性病毒性肝炎中A lb降低并不明显,而Che、PA降低明显,在其他各型病毒性肝炎中A lb、Che、PA浓度均明显减低,显著低于健康对照组,且三者呈正相关。结论:血浆Che、PA比白蛋白能更早更敏感的反映肝脏合成功能的损伤、恢复程度,三者联合检测对病毒性肝炎的分型鉴别、预后、用药的疗效有着重要的临床意义。     

“养肝柔筋方”对大鼠耐运动性疲劳能力和血清、股四头肌AChE活性的影响

目的探讨"养肝柔筋方"抗运动性疲劳作用的现代机制.方法选用游泳训练导致大鼠运动性疲劳模型,用生化检测方法,研究运动大鼠血清和股四头肌中胆碱酯酶(AChE)活性的变化,及"养肝柔筋方"对其变化的影响.结果与安静对照组比较,运动性疲劳组大鼠血清和股四头肌中AChE活性均降低(P<0.01),而灌胃"养肝柔筋方"组大鼠血清和股四头肌中AChE活性均提高(P<0.01).结论"养肝柔筋方"可显著提高大鼠运动状态下血清和股四头肌中AChE活性,这可能是该方抗运动性疲劳的机制之一.     

Efficacy of biperiden and atropine as anticonvulsant treatment for organophosphorus nerve agent intoxication

The ability of the nerve agents tabun, sarin, soman, GF, VR, and VX to produce brain seizures and the effectiveness of the anticholinergics biperiden HCl or atropine SO₄ as an anticonvulsant treatment were studied in a guinea-pig model. All animals were implanted a week prior to the experiment with cortical electrodes for electroencephalogram (EEG) recordings. On the day of exposure, the animals were pretreated with pyridostigmine (0.026 mg/kg, i.m.) 30 min prior to challenge with a 2 × LD₅₀ dose (s.c.) of a given agent. In separate experiments, animals were challenged with 5 × LD₅₀ (sc) of soman. One minute after agent challenge, the animals were treated intramuscularly (i.m.) with 2 mg/kg atropine SO₄ admixed with 25 mg/kg 2-PAM Cl and then observed for the onset of seizure activity. Five minutes after the start of nerve agent-induced EEG seizures, animals were treated i.m. with different doses of biperiden HCl or atropine SO₄ and observed for seizure termination. The anticonvulsant ED₅₀ of biperiden HCl and atropine SO₄ for termination of seizures induced by each nerve agent was calculated and compared. With equally toxic doses (2 × LD₅₀) of these agents, continuous EEG seizures (status epilepticus) developed in all animals challenged with soman, tabun, or VR, and in more than 90% of the animals challenged with GF or sarin. In contrast, only 50% of the animals developed seizures when challenged with VX. The times to onset of seizures for soman, tabun, GF, and sarin were very similar (5–8 min) while for VR, it was about 10 min. In the case of VX, not only was the time to seizure development longer (20.7 min), but the seizure activity in 19% of the animals terminated spontaneously within 5 min after onset and did not return. Under these conditions, the anticonvulsant ED₅₀s of biperiden HCl for soman, GF, VR, tabun, sarin, and VX were 0.57, 0.51, 0.41, 0.2, 0.1, and 0.09 mg/kg, respectively, while those of atropine SO₄ for soman, VR, tabun, GF, sarin, and VX were 12.2, 11.9, 10.4, 10.3, 5.1, and 4.1 mg/kg, respectively. In separate experiments, the anticonvulsant ED₅₀ doses of biperiden for animals challenged with 2 or 5 × LD₅₀ of soman were 0.48 (95% confidence limits 0.25–0.73) or 0.57 (95% CI 0.38–0.84) mg/kg, respectively, while the anticonvulsant ED₅₀s for atropine (12.2 mg/kg, i.m.) were identical under these same two challenge conditions. The present study demonstrates that all nerve agents can produce status epilepticus and that the therapeutic effectiveness of atropine and biperiden roughly paralleled the seizurogenic potential of these agents. Received: 16 November 1999 / Accepted: 9 February 2000     

Effect of poisoning by soman (pinacolyl methylphosphonofluoridate) on the serum half-life of the cholinesterase reactivator HI-6 in mice

The effect of fasting, atropine, and poisoning by an organophosphate anticholinesterase soman (pinacolyl methylphosphonofluoridate) on the pharmacokinetics of the acetylcholinesterase oxime reactivator HI-6 (CAS Reg. No. 34433-31-3; 1-[(4-(aminocarbonyl)pyridinio)methoxy)methyl)-2-(hydroxy imino)methyl) pyridinium dichloride) was investigated. Pharmacokinetic parameters (elimination half-life, volume of distribution, clearance rate) were determined for the following groups: (1) a 20 and 50 mg kg-1 dose of HI-6; (2) a 50 mg kg-1 dose of HI-6 after fasting for 18 h (water ad lib); (3) a 50 mg kg-1 dose of HI-6 at 0, 4, and 24 h after atropine (17.4 mg kg-1, i.p.) and soman (287 micrograms kg-1, s.c.); and (4) a 50 mg kg-1 dose of HI-6 at 0 and 4 h after soman (100 micrograms kg-1, s.c.). Fasting increased significantly (p less than 0.05) the elimination of half-life (t1/2) and tended to increase the volume of distribution (Vd) and decrease the clearance rate (CL). Following soman (287 micrograms kg-1) poisoning the t1/2 of HI-6 increased from 8.6 min to 21.6 min and the Vd increased to 0.731 kg-1. At the lower soman dose (100 micrograms kg-1) no significant effect on HI-6 pharmacokinetics was found. Atropine (17.4 mg kg-1: i.p.) pretreatment increased the t1/2 and CL while having no effect on the Vd. By 24 h the pharmacokinetic parameters of HI-6 in the various treatment groups were not significantly different from the control group. The changes in the pharmacokinetics of HI-6 following soman and atropine are probably the result of haemodynamic changes.     

Changes in the sensitivity to cholinomimetic drugs of smooth and cardiac muscle in the rat induced by subacute administration of di-isopropyl phosphorofluoridate

The effect of subacute administration to rats of di-isopropyl phosphorofluoridate (DFP) on the sensitivity of the cardiovascular system to carbachol and on the sensitivity of various isolated tissues to acetylcholine, methacholine and carbachol was investigated. Cholinesterase inhibition produced by DFP in the isolated tissues was also determined.In the cardiovascular experiments both the magnitude of responses and the slope of the dose-response curves for hypotension and bradycardia produced by carbachol in the anaesthetized rat were reduced in the DFP-treated group.In experiments with isolated tissuesfrom DFP-treated animals it was found that sensitivity to methacholine and acetylcholine increased in the bladder to a greater extent that in the atria or ileum. The sensitivity to carbachol decreased to a similar extent in all 3 tissues. Acetylcholinesterase and butyrylcholinesterase levels in the bladder were inhibited to a greater extent than in the other 2 tissues.The results show that the degree of enzyme inhibition produced by DFP in the tissues after subacute administration for 10 days does not correlate with the decrease in the sensitivity of the tissues to carbachol. It is suggested that the association between accumulation of transmitter and enzyme inhibition is a more important factor than the degree of enzyme inhibition itself in the development of subsensitivity to carbachol.The release of cholinergic transmitter from the electrically stimulated isolated rat bladder may also be impaired following subacute administration of DFP.     

Effects of food deprivation,discrimination experience and physostigmine on choline acetylase and acetylcholine esterase in the dorsal hippocampus and frontal cortex of rats

The effects of food deprivation and preliminary training treatments on choline acetylase and acetylcholine esterase activity in the dorsal hippocampus and frontal cortex of rats have been investigated. In addition, blood sugar and adrenal epinephrine levels were examined. The activity of choline acetylase and the levels of blood sugar and adrenal epinephrine were significantly altered during various stages of preliminary training but all values were comparable to pre-experimental levels before discrimination commenced. In addition, rats were injected physostigmine salicylate (0.25 mg/kg) or saline i.p. each day immediately after receiving three training trials on a food-motivated black-white task. The physostigmine injected rats were significantly better than the controls in rate learning.No differences were observed in choline acetylase activity in the dorsal hippocampus and frontal cortex in discriminating rats treated with physostigmine or saline. However, choline acetylase activity is lower in treated and control rats which did not discriminate at the end of the 14th session.     

Bifunctional drug derivatives of MAO-B inhibitor rasagiline and iron chelator VK-28 as a more effective approach to treatment of brain ageing and ageing neurodegenerative diseases

Degeneration of nigrostriatal dopamine neurons and cholinergic cortical neurones are the main pathological features of Parkinson's disease (PD) and for the cognitive deficit in dementia of the Alzheimer' type (AD) and in dementia with Lewy bodies (DLB), respectively. Many PD and DLB subjects have dementia and depression resulting from possible degeneration of cholinergic and noradrenergic and serotonergic neurons. On the other hand, AD patients may also develop extrapyramidal features as well as depression. In both PD and AD there is, respectively, accumulation of iron within the melanin containing dopamine neurons of pars compacta and with in the plaques and tangle. It has been suggested that iron accumulation may contribute to the oxidative stress induced apoptosis reported in both diseases. This may result from increased glia hydrogen peroxide producing monoamine oxidase (MAO) activity that can generate of reactive hydroxyl radical formed from interaction of iron and hydrogen peroxide. We have therefore prepared a series of novel bifunctional drugs from the neuroprotective-antiapoptotic antiparkinson monoamine oxidase B inhibitor, rasagiline, by introducing a carbamate cholinesterase (ChE) inhibitory moiety into it. Ladostigil (TV-3326, N-propargyl-3R-aminoindan-5yl)-ethyl methylcarbamate), has both ChE and MAO-AB inhibitory activity, as potential treatment of AD and DLB or PD subjects with dementia Being a brain selective MAO-AB inhibitor it has limited potentiation of the pressor response to oral tyramine and exhibits antidepressant activity similar to classical non-selective MAO inhibitor antidepressants by increasing brain serotonin and noradrenaline. Ladostigil inhibits brain acetyl and butyrylcholinesterase in rats and antagonizes scopolamine-induced inhibition of spatial learning. Ladostigil like MAO-B inhibitor it prevents MPTP Parkinsonism in mice model and retains the in vitro and in vivo neuroprotective activity of rasagiline. Ladostigil, rasagiline and other propargylamines have been demonstrated to have neuroprotective activity in several in vitro and in vivo models, which have been shown be associated with propargylamines moiety, since propargylamines itself possess these properties. The mechanism of neuroprotective activity has been attributed to the ability of propargylamines-inducing the antiapoptotic family proteins Bcl-2 and Bcl-xl, while decreasing Bad and Bax and preventing opening of mitochondrial permeability transition pore. Iron accumulates in brain regions associated with neurodegenerative diseases of PD, AD, amyotrophic lateral sclerosis and Huntington disease. It is thought to be involved in Fenton chemistry oxidative stress observed in these diseases. The neuroprotective activity of propargylamines led us to develop several novel bifunctional iron chelator from our prototype brain permeable iron chelators, VK-28, possessing propargylamine moiety (HLA-20, M30 and M30A) to iron out iron from the brain. These compounds have been shown to have iron chelating and monoamine oxidase A and B selective brain inhibitory and neuroprotective-antiapoptotic actions.     

氯解磷定对急性氧乐果中毒大鼠的疗效和作用机制

目的　探讨肟类药物氯解磷定 (PAM Cl)对急性氧乐果中毒大鼠的疗效和作用机制。方法　比较氧乐果染毒 ( 5 0mg/kg ,灌胃 )大鼠PAM Cl治疗组与未治疗组中毒症状及全血胆碱酯酶 (ChE)活力的变化 ,并用电刺激单纤维肌电图 (SSFEMG)研究PAM Cl对急性氧乐果中毒大鼠神经肌肉传导 (NMT)的影响。结果 ( 1)氧乐果染毒大鼠在给予PAM Cl治疗后 ,中毒症状减轻 ,症状出现时间延迟 ,存活时间明显延长 ;( 2 )PAM Cl治疗和未治疗组全血ChE活力无明显差异 (t =0 19,P >0 0 5 ) ;( 3 )急性氧乐果中毒大鼠腓肠肌的单肌纤维动作电位平均连续差 (MCD)[( 3 2 78± 5 79) μs]比正常对照大鼠MCD [( 19 3 3± 1 3 0 ) μs]明显延长 ,差异有显著性 (t =7 87,P <0 0 0 1) ;在给予PAM Cl治疗后 ,MCD [( 2 4 2 7± 6 48) μs]明显低于治疗前 (配对t=14 2 ,P <0 0 0 1) ,而与正常对照大鼠MCD差异无显著性 (t=1 67,P >0 0 5 )。结论　PAM Cl对急性氧乐果中毒有治疗作用 ,该作用是通过改善神经肌肉传导阻滞来实现的 ,即“非ChE重活化效应”。     

Electron microscopic localization of cholinesterase activity in Alzheimer brain tissue

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity was localized by electron microscopic enzyme cytochemistry in cortex from Alzheimer brains and brains from non-demented cases. In the tangle-rich medial temporal cortex of the Alzheimer brain, most of the neuronal AChE was associated with neurofibrillary tangles. These structures also contained BChE activity. In normal neurons AChE activity was found in the rough endoplasmic reticulum, nuclear envelope and Golgi apparatus. Little BChE activity was noted in normal cortex. In neuritic plaques, AChE and BChE activity was associated mostly with the amyloid, but also with the neuritic component.     

石杉碱甲改善中老年语词记忆障碍的临床研究

目的;观察石杉碱甲(Hup A)对不同程度中老年记忆功能障碍患者的语词记忆增强作用.方法;50例中老年记忆功能障碍患者,采用自身交叉双盲法分别给以Hup A 100 μg和安慰药,po,bid,每个疗程2周.测定服药前后语词记忆能力,辅以脑地形图和血胆碱酯酶活力检查.结果;轻、中度记忆功能障碍患者服用安慰药后回忆总数(∑R)分别增加(0.91±3.60)和(0.86±1.79)分,而服用Hup A后分别增加(6.05±2.87)和(6.43±2.24)分,长时再现数(LTR)、长时记忆数(LTS)、恒定长时再现数(CLTR)、未经提醒回忆数(UrR)也相应增加;服用安慰药后短时再现数(STR)分别增加(0.90±3.32)和(0.71±2.95)分,而服用Hup A后分别减少(1.90±3.78)和(2.36±2.62)分,不恒定长时再现数(RLTR)、提醒数(Pr) 和经提醒回忆数(RR)也有类似的变化.服用安慰药后轻、中度患者11次未通过全部语词回忆的有24例,而服用Hup A后仅有10例.Hup A使13例患者异常脑地形图改善或转为正常.与安慰药比较,这些变化在统计学上有显著或极显著性.但对记忆功能严重低下者大多无明显效果.未发现Hup A有严重的不良反应,外周血胆碱酯酶无明显抑制.结论;Hup A 主要对轻、中度中老年记忆功能障碍患者的语词铭记、保持和再现能力的提高有一定效果.