Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dose-effectiveness of pancuronium as it relates to membrane potentials, action potentials, electrical membrane constants, miniature endplate potentials, endplate potentials, and quantal release was studied in murine phrenic nerve-diaphragm preparations in vitro. Emphasis was placed on comparison of presynaptic with postsynaptic effects of pancuronium under similar experimental conditions. At low concentrations of pancuronium (5 X 10(-8) g/ml or less), no presynaptic effect was found. At high concentration (5 X 10(-7) g/ml), pancuronium depressed quantal release to 26 per cent of control in cut-fiber preparations and 40 per cent of control in high-magnesium preparations. Postsynaptic effects as measured by the amplitude of miniature endplate potentials and relative depolarization induced by 20 microns carbachol, revealed depression to 16 and 22 per cent of control, respectively, at a pancuronium concentration of 5 X 10(-7) g/ml. Pancuronium had no effect on directly elicited action potentials and electrical membrane constants. The authors conclude that presynaptic as well as postsynaptic effects of pancuronium in paralytic doses are essential in contributing to the total efficacy of neuromuscular depression.
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PMID:Pre- and postsynaptic effects of pancuronium at the neuromuscular junction of the mouse. 43 3

Total I.V. anesthesia was given to 20 patients using an Etomidate continuous infusion to maintain sleep, combined to Fentanyl analgesia, Droperidol, Pancuronium for muscular relaxation and artificial ventilation with an oxygen-air mixture. All these patients were carefully observed during and for several hours after the anesthesia and the results noted. With the Fentanyl dosages used in this technique, peroperative analgesia was frequently insufficient. More Fentanyl would probably be needed with the inherent dangers of prolonged postoperative depression.
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PMID:Total I.V. anesthesia using a continuous etomidate infusion. 54 55

The cardiovascular effects of 2 and 3 mg/kg of meperidine plus 60 to 67% N2O in O2 on cardiovascular dynamics in man were measured before and after the administration of 0.08 mg/kg of IV pancuronium. N2O and 2 mg/kg of meperidine did not change heart rate (HR) but produced a marked reduction (-49%) in cardiac output (QT) plus significant decreases in stroke volume (SV) and blood pressure (BP) and an increase in peripheral arterial resistance (PVR). Additional meperidine did not further alter any of the variables; however, surgical stimulation caused significant increases in HR, BP, and PVR. SV and QT were not significantly changed by surgical stimulation and were still markedly depressed when compared to control values. Pancuronium produced marked increases in HR, SV, QT, and BP and a reduction in PVR. These changes were maximal 4 to 8 minutes after pancuronium and returned toward pre-pancuronium values thereafter. These data demonstrate that N2O-meperidine anesthesia results in a moderate reduction in BP but a marked depression in QT. The findings also indicate that pancuronium reverses the cardiovascular depression produced by N2O-meperidine and is therefore, a desirable muscle relaxant when the above technic is employed.
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PMID:Cardiovascular effects of meperidine-N2O anesthesia before and after pancuronium. 56 91

Fifteen patients with impending uremic cardiac tamponade underwent either anterior pericardectomy or pericardiostomy under general anesthesia. Anesthetic agents and technics were selected in the light of physiopathologic derangements involving fluids and electrolyte balance, excretory and cardiovascular disturbances, and pharmacodynamics. Anesthesia was induced with diazepam and maintained with N2O-O2 (70:30) and fentanyl. Pancuronium was used for muscle relaxation. Adequate preoperative assessment of patient, careful monitoring of vital signs, maintenance of the critical balance of fluid and blood replacement, and selection of anesthetic agents for minimal depression of vital multiorgan systems provided excellent results. No postanesthetic morbidity or mortality occurred.
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PMID:Anesthetic considerations for pericardectomy in uremic pericardial effusion. 94 19

Pancuronium causes a powerful and highly selective inhibition of human serum cholinesterase in vitro. The inhibition was studied in serum from 14 individuals of both sexes (5-60 years of age) with normal reactions to suxamethonium. Pancuronium, in a concentration of 2.3 x 10(-7) M, caused a 50% inhibition of the enzymatic hydrolysis of acetylcholine, when this substrate was present in a concentration of 10 x 10(-3) M. The same I50 value was also found for a commercial preparation of human serum cholinesterase. The inhibition was reversible and competitive in type. Pancuronium inhibition of the acetylcholinesterase in human red blood cells and from the electric eel was more than one thousand times weaker. Thus pancuronium is one of the most selective inhibitors of serum cholinesterase described so far. The in vivo activity of the serum cholinesterase in four patients receiving pancuronium 0.1 mg/kg decreased, during the first 3 min, by 60-80%, from the pre-induction value. After this a slow recovery occurred with 40% depression remaining at 45 min after the injection. The tachycardia produced by pancuronium may be related to this selective inhibition of serum cholinesterase. It is suggested that relaxants which selectively inhibit serum cholinesterase also selectively block the cardiac muscarinic receptors.
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PMID:The inhibition of cholinesterases by pancuronium. 119 83

Anaesthesia for neurosurgical patients should provide haemodynamic stability, reduce cerebral metabolism, preserve cerebral autoregulation, avoid increases of intracranial pressure and guarantee rapid recovery without respiratory depression. A commonly used Balanced Anaesthesia (BA, n = 20) (thiopental and fentanyl bolus induction and maintenance with repetition boluses of fentanyl and droperidol, thiopental infusion, and isoflurane in N2O/O2) was compared to Total Intravenous Anaesthesia (TIVA, n = 20) with propofol and alfentanil infusion. Pancuronium was employed for muscle relaxation in both groups. The TIVA evinced more haemodynamic stability during induction; notably, there was no increase in blood pressure after intubation, as seen in the BA group. Another advantage of TIVA is that it obviates the use of N2O. Quality of recovery after the procedure was determined by standardised psychometric tests. The time span between awakening of patients to orientation and concentration was significantly shorter in the TIVA group compared to the BA group. There was also a smaller deviation of these parameters in the TIVA group indicating a more predictable recovery.
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PMID:[Total intravenous anesthesia using propofol and alfentanil in comparison with balanced anesthesia in neurosurgery]. 230 91

The effects of lidocaine or verapamil on pancuronium neuromuscular blockade and the ability of anticholinesterase agents to antagonize these combined blockades were studied in 14 cats using a standard peroneal nerve-anterior tibialis muscle preparation. Pancuronium was infused at a constant rate to produce a stable 50% depression of single twitch tension. In nine cats, intravenous lidocaine boluses followed by a constant infusion produced serum lidocaine levels of 5.09 +/- 1.9 micrograms/ml (mean +/- SD) and resulted in an additional 20.0 +/- 5.5% depression of twitch tension. In the other five cats, intravenous injection of 0.15 mg/kg of verapamil produced an additional 12.8 +/- 8.0% twitch depression of pancuronium-induced neuromuscular blockade. For individual animals, edrophonium antagonism of the combined lidocaine-pancuronium-induced neuromuscular blockade or combined verapamil-pancuronium-induced neuromuscular blockade was not significantly different from antagonism of an equivalent twitch depression produced by pancuronium alone. It is concluded that lidocaine and verapamil augment neuromuscular blockade caused by pancuronium and that anticholinesterase antagonism of this augmented blockade can be expected to occur in a normal fashion.
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PMID:Edrophonium antagonizes combined lidocaine-pancuronium and verapamil-pancuronium neuromuscular blockade in cats. 377 79

The inotropic effects of five non-depolarizing muscle relaxants were examined using an isolated canine heart muscle preparation. Except for fazadinium, all drugs were studied in their commercially available forms. d-Tubocurarine chloride (dTc) and metocurine iodide (MTC) produced dose-dependent decreases in isometric force (F) and the maximum velocity of force development (dF/dt) at concentrations greater than 22.5 x 10(-3) g/L for dTc and greater than 15.0 x 10(-3) g/L for MTC, concentrations which are 3 and 6 times higher than estimated clinical serum concentrations, respectively. Myocardial depression was about 3 times less with MTC than with dTc at equipotent concentrations. The degree of depression in F and dF/dt produced by MTC was almost identical with that produced by phenol, a preservative of MTC, indicating that MTC-induced myocardial depression may be due to the effect of the preservative. Pancuronium bromide (PC) produced a dose-dependent increase in F and dF/dt and decrease in the time to peak force. PC-induced changes in F, dF/dt, and time to peak force were inhibited by administration of propranolol 10(-6) M. The results indicate that PC possesses a positive inotropic effect mediated by beta-adrenergic stimulation. Alcuronium chloride did not change F or dF/dt at concentrations from 5.0 x 10(-3) to 60.0 x 10(-3) g/L. Frazadinium bromide increased F and dF/ dt slightly at a low concentration (1.875 x 10(-2) g/L), but further increases in its concentration returned the values of F and dF/dt to control levels. F and dF/dt were not altered in vitro by concentrations of relaxants that would be anticipated in plasma in vivo in patients given clinically effective doses of 0.3 mg/kg of dTc, 0.1 mg/kg of MTC or PC, 0.2 mg/kg of alcuronium chloride, or 0.75 mg/kg of fazadinium bromide.
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PMID:Inotropic effects of non-depolarizing muscle relaxants in isolated canine heart muscle. 610 62

The in vivo cat soleus and gastrocnemius muscles were used to compare isometric contraction strength and the train-of-four (T4) response (2 Hz for 2 s) of two muscle types (fast and slow) during onset of competitive neuromuscular blockade in order to determine the extent of the correlation between twitch depression and T4 fade. Prior to drug administration the muscles that were studied differed significantly in that the T4 ratio was 1.0 in the gastrocnemius and only 0.87 in the soleus. Three competitive neuromuscular-blocking agents were compared: d-tubocurarine, pancuronium, and vecuronium. d-Tubocurarine was found to produce a close correlation between the degrees of twitch strength depression and T4 for both muscles. However, these muscles demonstrated significantly different ED50 values (105 micrograms/kg for gastrocnemius, 150 micrograms/kg for soleus). Pancuronium also produced a similar relationship between twitch strength depression and T4 decrement for each muscle. In this case, however, there was little difference in their ED50 values for twitch depression (11.5 micrograms/kg for gastrocnemius, 13 micrograms/kg for soleus). The effects of vecuronium were quite different from the other two muscle relaxants. Although vecuronium produced a comparable correlation between twitch tension and T4 fade in fast muscle, no such relationship was found to exist in slow muscle. Even when the twitch strength was blocked to 18% of control, the soleus T4 response was depressed to only 75% of control. These results highlight major differences among competitive neuromuscular-blocking agents and suggest multiple sites of action.
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PMID:Characterization of the train-of-four response in fast and slow muscles: effect of d-tubocurarine, pancuronium, and vecuronium. 613 67

The effects on indirectly elicited muscle twitch amplitude associated with the calcium (slow) channel blocker, verapamil, with or without pancuronium were investigated using isolated bullfrog sciatic nerve-sartorius muscle preparations. Verapamil (2-8 mM) produced a dose-related depression of indirect muscle twitch height (P less than 0.05). Twitch response was depressed 11% below control by the lowest concentration employed and 86% by the highest concentration. Pancuronium (0.07 mM) depressed neuromuscular function 35% below control (P less than 0.05). The combination of 5 mM or 8 mM verapamil with 0.07 mM pancuronium caused significantly greater degrees of depression than either drug alone. Verapamil produced significant depression of twitch height in vitro in relatively high concentrations. The mechanism of action remains unknown. Verapamil possesses pharmacologic properties that may be unrelated to slow (calcium) channel inhibition. The reduction of muscle twitch height caused by verapamil alone (5 mM) could not be antagonized by neostigmine, calcium, or frequent washings.
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PMID:Effects of verapamil on indirect muscle twitch responses. 660 98


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