Protective effect of physostigmine and neostigmine against acute toxicity of parathion in rats

The effects of physostigmine and neostigmine on the parathin induced toxicity were examined in adult female rats. Physostigmine (100 μg/kg, ip) or neostigmine (200 μg/kg, ip) inhibited acetylcholinesterase (AChE) and cholinesterase (ChE) activities in blood, brain and lung when the enzyme activity was measured 30 min after the treatment. At the doses of two carbamates equipotent on brain AChE, neostigmine showed greater inhibition on peripheral AChE/ChE. The enzyme activity returned to normal in 120 min following the carbamates except in the lung of rats treated with neostigmine. Carbamates administered 30 min prior to parathion (2 mg/kg) antagonized the inhibition of AChE/ChE by parathion when the enzyme activity was measured 2 hr following parathion. Neostigmine showed greater protective effect on peripheral AChE/ChE. The effect of either carbamate on AChE/ChE was not significant 2 hr beyond the parathion treatment. Carbamates decreased the mortality of rats challenged with a lethal dose of parathion (4 mg/kg, ip) either when treated alone or in combination with atropine (10 mg/kg, ip). Lethal action of paraoxon (1.5 mg/kg, ip), the active metabolite of parathion, was also decreased by the carbamate treatment indicating that the protection was not mediated by competitive inhibition of metabolic conversion of parathion to paraoxon. The results suggest that carbamylation of the active sites may not be the sole underlying mechanism of protection provided by the carbamates.     

新斯的明对于术后尿潴留的疗效观察

目的　观察新斯的明用于术后尿潴留的效果及其副作用。方法　 2 4例病例随机分为两组 ,治疗组给予新斯的明肌注 ,对照组给予按摩、热敷、心理暗示等治疗 ,观察两组病人的排尿情况、感觉不适程度及药物副作用发生情况。结果　治疗组病人自行排尿率、首次排尿量均显著高于对照组 ,病人不适程度较轻 ,未发现明显药物副作用。结论　新斯的明肌注用于术后尿潴留具有起效迅速、有效率高、给药方便、副作用少的特点     

Reversal of atracurium-induced neuromuscular block in paediatric patients

We studied the efficacy of neostigmine and edrophonium to reverse an atracurium-induced 90% neuromuscular block in 80 paediatric patients anaesthetized with thiopentone, fentanyl and nitrous oxide. The patients were divided into five age groups: 0–2 months, 3–11 months, 2–5 years, 6–10 years, and 11–15 years. At the end of surgery, the neuromuscular block was randomly antagonized with either neostigmine 50 μg kg^-1 with atropine 20 μg kg^-1 or with edrophonium 1 mg kg^-1 with atropine 10 μg kg^-1. In general, the first EMG response and train-of-four (TOF) ratio recovered fastest in the youngest age groups following either reversal agent ( P <0.05). However, in each age group edrophonium had a faster onset of effect than neostigmine ( P <0.05) even though a greater TOF-ratio was finally reached with neostigmine. The effects of neostigmine were less variable and more predictable than those of edrophonium. Therefore, we recommend the use of neostigmine for routine paediatric practice.     

The effect of neostigmine on metoclopramide-induced aldosterone secretion after the administration of muscarinic antagonists in man

Summary In this study the effects of neostigmine on metoclopramide-induced aldosterone secretion were examined in the presence of a relatively selective M₁-antagonist, pirenzepine and of a non-selective muscarinic antagonist, atropine.Six normal male volunteers received metoclopramide, 10 mg i.v. on three different occasions, each study day being preceded by a day in which the intake of sodium and potassium was limited. The dosing was either metoclopramide alone or combined with either neostigmine and pirenzepine or with neostigmine and atropine.Serum aldosterone increased significantly with all three regimens. The highest levels were attained with the metoclopramide/neostigmine/prienzepine regimen and those were significantly higher than those after metoclopramide alone and also, from 45 min onwards, from those after the metoclopramide/neostigmine/atropine regimen.The results of this investigation suggest that the metoclopramide-induced aldosterone secretion in humans is augmented by an accumulation of acetylcholine at the nerve-zona glomerulosa junctions and that the receptors mediating aldosterone secretion are of the M₂-subclass of muscarinic receptors.     

硬膜外腔新斯的明和／或吗啡术后镇痛效果的比较

目的：探讨硬膜外腔应用新斯的明，吗啡的术后镇痛效果和副作用。     

新斯的明和阿托品用于肌松拮抗时对血流动力学的影响

为观察全麻术后应用新斯的明和阿托品进行肌肉松弛 (以下简称肌松 )拮抗对血流动力学的影响 ,将 2 1例术中持续吸入异氟醚维持麻醉、间断静脉注射哌库溴铵维持肌松的择期颅脑手术患者 (ASAⅠ～Ⅱ级 ) ,术后随机分组 ,静脉注射不同剂量新斯的明和阿托品 (Ⅰ组新斯的明 0 .0 5mg/kg、阿托品 0 .0 2 5mg/kg ;Ⅱ组新斯的明 0 .0 5mg/kg、阿托品0 .0 1 7mg/kg) ,拮抗肌松残余作用。用DATEX多功能监测仪和HEMOSONICTM 1 0 0经食管超声多普勒仪连续监测给药前后血流动力学各参数的变化。结果 :2组病人给药后 1、2、3min心率都明显增快 ,Ⅱ组给药后 3 0min心率和峰值血流速度 (PV)明显降低 ,其他血流动力学参数给药前后均无明显变化。提示 :0 .0 5mg/kg新斯的明配伍 0 .0 1 7mg/kg阿托品进行肌松拮抗时易引起延迟性心动过缓 ,且抑制心肌收缩力 ;对于无器质性心脏病、无心肌缺血的病人 ,0 .0 5mg/kg新斯的明和 0 .0 2 5mg/kg阿托品为较好的配伍。     

Reversal of pancuronium

Moderate to deep (67-99% single twitch depression) pancuronium-induced neuromuscular blockade was antagonised with neostigmine (30 micrograms/kg, 60 micrograms/kg, or 80 micrograms/kg) in combination with glycopyrronium. Twenty-seven patients were reversed from 91%-99% twitch depression. Recovery of the first twitch of a train-of-four to 95% of control twitch took at least 20 minutes with neostigmine 30 micrograms/kg. The higher doses were significantly faster (60 micrograms/kg p less than 0.05, 80 micrograms/kg p less than 0.01) and took 15.8 and 14.8 minutes respectively. Reversal to a train of four ratio of 0.75 was not consistently achieved in under 30 minutes with any dose of neostigmine. Nineteen patients were antagonised from a 67%-80% depression of first twitch and in all but two recovery to 95% of control took under 10 minutes. To achieve a train of four ratio of 0.75 took less than 12.5 minutes except in three patients, two of whom, both given neostigmine 30 micrograms/kg, took longer than 20 minutes. Neostigmine 60 micrograms/kg produced as rapid a degree of antagonism as 80 micrograms/kg. Heart rates after reversal decreased gradually in all groups, although the decrease was initially greater in the low dose neostigmine (30 micrograms/kg) group. A fixed 5:1 ratio of neostigmine and glycopyrronium will usually antagonise a moderate (70%-80%) pancuronium block to a train of four of greater than 75% within 12.5 minutes if at least 60 micrograms/kg of neostigmine is administered. More than 30 minutes may be required for reversal whatever the dose of neostigmine, for antagonism from greater than 90% twitch depression.     

Edrophonium and Neostigmine for Reversal of the Neuromuscular Blocking Effect of Vecuronium

The effect of edrophonium for reversal of the non-depolarizing neuromuscular blockade produced by a continuous infusion of vecuronium was compared to that of neostigmine in 20 adult patients during neurolept anaesthesia. When antagonism was attempted at 10% twitch height recovery, reversal time to a train-of-four ratio of 0.7 was significantly shorter following neostigmine 0.04 mg/kg than after edrophonium 0.75 mg/kg (9.8 min and 18.7 min, respectively) but the same after edrophonium 1.5 mg/kg (10.3 min). There was no statistically significant difference in reversal time between neostigmine 0.04 mg/kg given at 10% twitch height and edrophonium 0.75 mg/kg given at 25% twitch height recovery (6.0 min). Additional doses of atropine were necessary following edrophonium 1.5 mg/kg.     

Effect of ethanol on motor activity of the colon in the rat

The present study was designed to evaluate the influence of oral and intravenous ethanol on both resting and neostigmine-induced motor activity of the colon in the rat. Recording assemblies were implanted in the proximal and distal colon in a chronic preparation. On separate days, 2 ml of normal saline or the same volume of 10% or 25% ethanol was introduced intravenously or into the stomach. Colon motor activity was recorded at resting and after intravenous injection of 0.07 mg/kg neostigmine. Ethanol decreased the number and amplitude of the contractions. This effect occurred within a few minutes after administration of ethanol and lasted for the entire recording period of 30 min. Both concentrations of ethanol significantly (P < 0.05) decreased the motility index of the colon. Injection of neostigmine was signified by a substantial rise in colon motor activity which was significantly inhibited by administration of ethanol. These studies indicate that ethanol, within the human legal intoxication range, inhibits the resting and neostimine-induced motor activity in the rat colon.