No abstract available.
Humans ; Paralysis* ; Pseudocholinesterase* ; Succinylcholine*

Serum pseudocholinesterase activities, using butyrylthiocholine as substrate, measured in 639 employees of Korea Cancer Center Hospital in 1993. Overall mean value of pseudocholinesterase was 9.38+/-2.10 U/ml, 10.6+/-2.10 U/ml in male, and 8.58+/-1.67 U/ml in female, respectively. Male in the first five decades of life had higher pseudocholinesterase activity than female, and after the age of 50 tbere was no intersexual difference. These findings suggest that adults before the age of 50, male has higher pseudocholinesterase activity than female.
Adult* ; Butyrylthiocholine ; Female ; Humans ; Korea ; Male ; Pseudocholinesterase*

The interaction between succinylcholine(SCC) and non-depolarizer; atracurium or vecuronium, was investigated in 36 cats of either sex using the sciatic nerve-anterior tibialis muscle preparation. And also, its relation to the pseudocholinesterase activity was examined. The duration of action of vecuronium(6.5+/-1.3 to 7.3+/-2.2 minutes) in cats pretreated with SCC was greater than those(2.0+/-0.6 minutes) in non-pretreated cats. However, SCC had no influence on the duration of atracurium. The serum pseudocholinesterase activity was decreased after the injection of atracurium or neostigmine in contrast to vecuronium. The authors conclude that the prior administration of SCC prolongs the duration of vecuronium but not that of atracurium, and pseudocholinesterase activity is not related to the prolonging effect of SCC.
Animals ; Atracurium* ; Cats* ; Neostigmine ; Pseudocholinesterase ; Succinylcholine* ; Vecuronium Bromide*

Plasma cholinesterase was assayed during the period immediately following IV bolus injection of succinylcholine 1mg/kg to test the effect of succinylcholine on pseudocholinesterase activity. Twenty healthy adult patients scheduled for elective surgery were studied. The resutls were as follows: The mean value of pre-injection pseudocholinesterase activity was 1124.15 IU/L, and the activity following succinylcholin injection was 1159.55IU/L during fasciculation, 982.70 at 1 min, 936.60 at 3 min, 891.25 at 5 min, 926.80 at 7 min, 1015.45 at 10 min, and 1007.70 at 15 min. It was concluded that the tendency to increase pseuducholinesterase activity during fasciculation seems to be due to choline, the metabolite of succinylcholine, however the cause of the significant decrease in pseudocholinesterase activity after fasciculation is uncertain. The only suggested mechanism is due to the inhibition of pseudocholinesterase by succinylcholine and its metabolites.
Adult ; Choline ; Cholinesterases ; Fasciculation ; Humans ; Plasma ; Pseudocholinesterase ; Succinylcholine*

Pseudocholinesterase is an essential enzyme for hydrolysis of succinylcholine and some people has low activity. The pseudocholinesterase from a normal individual has a greater apparent affinity for the cholinester substrate than the enzyme from succinylcholine-sensitive individuals, who has genetic variants. The ideal situation would be one in which a single, simple test would detect and identify all the variant forms of enzyme, but no such test currently exsits. The inhibitors frequently used to identify variants are dibucaine, fluoride, chloride, urea or succinylcholine as inhibition numbers. The authors found that dibucaine, fluoride and chloride numbers in Korean adults (mean+/-SD, %) are 85.8+/-1.83, 46.5+/-2,05 and 3.53+/-1.64, respectively (substrate is butyrylthiocholine).
Adult* ; Dibucaine ; Fluorides ; Humans ; Hydrolysis ; Pseudocholinesterase* ; Succinylcholine ; Urea

BACKGROUND: Mivacurium is a nondepolarizing muscle relaxant and metabolized by pseudo-cholinesterase(pChe). Many reports show fall in pChe activity during pregnancy, so the metabolism of mivacurium may be delayed and muscle relaxation would be prolonged. METHODS: Muscle relaxation of full-term pregnant women(C group, n=10) and nopregnant women(Non-C group, n=10) was maintained by continuous infusion of mivacurium to keep 1st response of TOF at 5+/-1%. After discontinuance of infusion, recovery profiles were measured with accelerography. RESULTS: The Infusion rate of mivacurium to maintain 1st twich response of TOF at 5+/-1% was significantly low in C group comparing with Non-C group(P<0.05). There was no significant difference in pChe activity between two groups. There was no significant difference in recovery index, recovery time(T1 25%-T4 ratio, 0.75). There was a little correlation between the total infusion time and recovery profiles(recovery index: r2=0.37, recovery time: r2=0.28). Strong correlation existed between bolus-TS(time interval from the injection of mivacurium to recovery of 5% twitch hight) and infusion rate(r2=0.76). CONCLUSION: The mivacurium infusion rate of C group to maintain muscle relaxation was significantly lower than Non-C group. There would be many possible reasons including over-estimation of paturient body weight compared with lean body mass, decrease of blood volume due to hemorrhage.
Blood Volume ; Body Weight ; Cesarean Section* ; Female ; Hemorrhage ; Metabolism ; Muscle Relaxation ; Obstetrics ; Pregnancy ; Pseudocholinesterase

BACKGROUND: Mivacurium is a nondepolarizing muscle relaxant and metabolized by pseudo-cholinesterase(pChe). Many reports show fall in pChe activity during pregnancy, so the metabolism of mivacurium may be delayed and muscle relaxation would be prolonged. METHODS: Muscle relaxation of full-term pregnant women(C group, n=10) and nopregnant women(Non-C group, n=10) was maintained by continuous infusion of mivacurium to keep 1st response of TOF at 5+/-1%. After discontinuance of infusion, recovery profiles were measured with accelerography. RESULTS: The Infusion rate of mivacurium to maintain 1st twich response of TOF at 5+/-1% was significantly low in C group comparing with Non-C group(P<0.05). There was no significant difference in pChe activity between two groups. There was no significant difference in recovery index, recovery time(T1 25%-T4 ratio, 0.75). There was a little correlation between the total infusion time and recovery profiles(recovery index: r2=0.37, recovery time: r2=0.28). Strong correlation existed between bolus-TS(time interval from the injection of mivacurium to recovery of 5% twitch hight) and infusion rate(r2=0.76). CONCLUSION: The mivacurium infusion rate of C group to maintain muscle relaxation was significantly lower than Non-C group. There would be many possible reasons including over-estimation of paturient body weight compared with lean body mass, decrease of blood volume due to hemorrhage.
Blood Volume ; Body Weight ; Cesarean Section* ; Female ; Hemorrhage ; Metabolism ; Muscle Relaxation ; Obstetrics ; Pregnancy ; Pseudocholinesterase

There is a direct relationship between the plasma concentration of the drugs and the magnitude of neuromuscular blockade in non-depolarizing neuromuscular blocking agents. But the classical pharmacokinetic data of succinylcholine have not been obtained because of the lack of an appropriate assay to detect plasma concentration hydrolyzed rapidly by pseudocholinesterase. The purposes of this study was to determine neuromuscular response from the release of minute interval of toumiquet occlusion after intravenous bolus adminstration of succinylcholine at one arm following blood flow occlusion at contralateral arm with pneumatic toumiquet. The twitch height of neuromuscular responses after adminisration of succinylcholine was completely depressed in the group(control) without occlusion, but 5.40+/-3.63% on 1 minute, 30.11+/-9.72% on 2 minutes, 85.00+/-4.19% on 4 minutes and 97.75+/-0.59% on 5 minutes after blood flow occlusion respectively. The onset time of maximum depression in each group was not significant different. At 5 minutes after succinylcholine given systemically, the twitch height was 8.35%, while it was 97.75% from tourniquet release on 5 minutes after blood flow occlusion. It is concluded that succinylcholine should be also related to plasma concentration in magnitude of neuromuscular block, and receptor binding(dissociation constant) more than plasma concentration in offset of neuromuscular blockade.
Arm ; Depression ; Neuromuscular Blockade ; Neuromuscular Blocking Agents ; Plasma ; Pseudocholinesterase ; Succinylcholine* ; Tourniquets

The interaction between succinylcholine (SCC) and anticholinegterase drugs is illustrated by the inhibition of acetylcholine hydrolysis or a decrease in pseudocholinesterase activity- The present study was performed in order to estimate the action duration of SCC and pseu- docholinesterase activity following the administeration of neostigmine or pyridostigmine. Thirty-two healthy adult patients under general inhalation anesthesia with either halothane or enflurane were given two 1 mg/kg doses of SCC intravenously. The first dose was givenimmediatelr before intubation while the tole second dose was administered when recovery to the single twitch response was at 75% following a 0.035 mg/kg dose of neostigmine (group l) or a 0.175 mg/kg dose of pyridostigmine (group ll). Delete this phase or explain it better , Electromrographic monitoring(with Relaxograph, ABM , Datex) was employed for the duration of the SCC-induced block. Pseudocholinesterase activity was measured immediately before the first dose of SCC, at the 75% twitch recovery after reversal, and at the 75% twitch recovery after the second dome of SCC. The duration of the second dose or SCC in groups l and ll, 31.62+/-5.91 and 29.94+/-6.91 min.. repectively, was significantly prolonged from that of the first dose(groups l and ll , 18.38+/-8.85 and 18.24+/-6.47 min., respectively, but there was no significant difference between the two groues, Train-of-four ratio following the second dose of SCC was found to be 74.44+/-19.12 and 51. 73+/-18.80 per cent in groups l and ll, respectively, and there was no difference between the two groups. The recovery of 75% single twitch from the second dose of SCC was observed, while pseudocholinesterase activity remained suppressed at 50.8 and 44.3 per cent in groups l and ll, respectively. It is suggested that the SCC-induced block following administration of anticholinesterase drugs such as neostigmine or pyridostigmine may be prolonged due to decreased pseudocho-linesterase activity and that the mode of action may be transformed to a phase ll block.
Acetylcholine ; Adult ; Anesthesia, Inhalation ; Cholinesterase Inhibitors* ; Enflurane ; Halothane ; Humans ; Hydrolysis ; Intubation ; Neostigmine ; Neuromuscular Blockade* ; Pseudocholinesterase ; Pyridostigmine Bromide ; Succinylcholine

BACKGROUND: Mivacurium is a nondepolarizing neuromuscular blocking agent hydrolyzed by pseudocholinesterase. Anticholinesterase used in the reversal of mivacurium-induced muscle relaxation may also inhibit plasma pseudocholinesterase, and delay hydrolysis of mivacurium. In this study, the effects of edrophonium and/or bovine pseudocholinesterase (BpChE) in the reversal of mivacurium were investigated with the rat phrenic nerve-diaphragm preparation. METHODS: Fifty Sprague-Dawley rats (150 - 200 g) were randomly allocated into 10 groups based on the dosage of edrophonium and BpChE. Each animal was anesthetized with thiopental sodium (40 mg/kg I.P.). The phrenic nerve-diaphragm was dissected and mounted in a bath containing an oxygenated Krebs' solution at 32degreesC. The phrenic nerve was stimulated at supramaximal intensity and the single twitch responses and train of four (TOF) ratio were measured. After stabilization of the twitch responses, mivacurium (1ng/ml) was administered incrementally to obtain more than 95% twitch inhibition. Reversal of the mivacurium-induced block by edrophonium (0.01, 0.1, 1, or 10ng/ml) and/or BpChE (0.1 u, or 1.0 u/ml) were tested. A single twitch height more than 75% of the baseline value was considered an adequate reversal. RESULTS: Mivacurium-induced paralysis was recovered more effectively by BpChE 1.0 u/ml than the other groups. Edrophonium improved a single twitch in a dose dependent manner. CONCLUSIONS: Mivacurium-induced paralysis can be more effectively reversed by BpChE than edrophonium. Inhibition of pseudocholinesterase was not observed by increasing the dose of edrophonium.
Animals ; Baths ; Edrophonium* ; Hydrolysis ; Muscle Relaxation ; Neuromuscular Blockade ; Oxygen ; Paralysis* ; Phrenic Nerve ; Plasma ; Pseudocholinesterase* ; Rats ; Rats, Sprague-Dawley ; Thiopental