Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026837 (muscle rigidity)
 1,077 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In addition to anamnestic and clinical data electrophysiological and pharmacokinetic investigations may be necessary for the diagnosis of stiff man syndrome. Continuous activity of motor units with superimposed bursts during muscular spasms was found by electromyography in the two patients reported. Rigidity and continuous activity disappears during sleep, after i.v. application of Tubocurarine and Diazepam, during Thiopenal anesthesia and after neural block with Procaine. Dipropylacetate and Baclofen improved the condition but did not lead to complete relaxation. Biperidenlactat and Magnesiumlaevulinat have only a temporary effect on rigidity. Neostigmine, Phenytoine, Glycine, Dopa and 5-Hydroxy-Tryptophan had no effect. Passive shortening or stretching of the m. biceps brachii as well as touching the skin increased motor activity which spread to other segments and to the contralateral side. The H/M ratio was increased but the silent period was normal. A combination of Diazepam and Dipropylacetate or Clonazepam was therapeutically effective in the cases reported. A central genesis, of the pathogenetic mechanisms discussed, is the most probable in our cases.
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PMID:Electrophysiological studies on the "stiff-man" syndrome. 7 57

Effects of ID-690 on motor systems were compared with those of clonazepam, diazepam and nitrazepam. ID-690 exerted muscle relaxant action in the rotarod method using rats and mice; this action was almost equal in potency to clonazepam and nitrazepam and more potent than diazepam. Pretreatment with ID-690, clonazepam and nitrazepam increased the sleeping time of mice under thiopental anesthesia to the same degree, whereas diazepam produced a lesser effect. ID-690 was almost equal in potency to diazepam and nitrazepam in protecting against oxotremorine-induced tremor in mice, and approximately 10 times as potent as clonazepam. The anticonvulsant action of ID-690 was similar to that of clonazepam. These benzodiazepines effectively augmented the dorsal root reflexes, while showing no effects on the ventral root reflexes. Rigidity in rats due to anemic decerebration was not affected after intraduodenal administration of these drugs, while phasic augmentation of the rigidity by mechanical stimulation of the hind limb was clearly depressed. These drugs had no effects on the neuromuscular junction. From these results, it is concluded that ID-690 has a wider pharmacological spectrum than clonazepam, is almost equal in potency to nitrazepam and is more potent than diazepam.
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PMID:[Pharmacological study on 5-(o-chlorophenyl)-1-methyl-7-nitro-1,3-dihydro-2H-1,4-benzodiazepin-2-one (ID-690), with special reference to the effects on motor systems]. 55 42

Fentanyl (10 mug/kh) or fentanyl (10 mug/kg) plus droperidol (100 mug/kg) administered intravenously during 20 minutes to adult patients with acquired valvular heart disease produced minimal circulatory changes. The trend during drug infusion was for mean arterial pressure and systemic vascular resistance to decrease, and for cardiac index and stroke volume index to increase without change in heart rate. Central venous pressure increased during drug infusion (P less than 0.05) but decreased to awake levels following controlled ventilation and skeletal-muscle paralysis, probably reflecting thoracoabdominal-muscle rigidity rather than a circulatory response. Hypoventilation during drug infusion necessitated assisted or controlled ventilation, with or without skeletal muscle paralysis, in 14 of 16 patients. Addition of 60 per cent nitrous oxide following fentanyl or fentanyl-droperidol infusion significantly decreased mean arterial pressure, heart rate, and cardiac index. All circulatory changes were similar in direction and extent to those previously found during morphine-nitrous oxide anesthesia. (Key words: Anesthetics, intravenous, fentanyl; Anesthetics, gases, nitrous oxide; Heart, effect of fentanyl, dorperidol, and nitrous oxide.).
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PMID:Hemodynamic and ventilatory responses to fentanyl, fentanyl-droperidol, and nitrous oxide in patients with acquired valvular heart disease. 111 86

Anaesthesia can induce skeletal muscle rigidity, hypermetabolism and high fever in humans genetically predisposed to malignant hyperthermia. If not immediately reversed, such episodes can lead to tissue damage and death. In swine with the corresponding condition, stress can induce death or lead to devalued meat products. Since muscle contraction is controlled by sarcoplasmic Ca2+, the abnormality, as reviewed here by David H. MacLennan, could reside in the skeletal muscle Ca(2+)-release channel gene, RYR1. Several observations support the view that a single RYR1 mutation is causal of malignant hyperthermia in all breeds of pigs and in at least some human families: the substitution of Cys for Arg615 as the sole deduced amino acid sequence change in a comparison of malignant hyperthermia and normal porcine RYR1 cDNAs; the linkage of this mutation to malignant hyperthermia in over 450 pigs in six breeds, including 338 meioses; and the appearance of the corresponding mutation, Cys for Arg614, across a species barrier, in a few human families, where it also cosegregates with malignant hyperthermia. Linkage of malignant hyperthermia to RYR1 is, however, not observed in all human families with malignant hyperthermia. Accordingly, other abnormal genes that may cause the condition are being sought.
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PMID:The genetic basis of malignant hyperthermia. 132 95

In the last two decades, opioid analgesics have assumed an important place in general anesthetic practice in the United States. Part of the reason for this has been the introduction of the potent new agonists fentanyl, sufentanil, and alfentanil. Because of problems with morphine-oxygen anesthesia (incomplete amnesia, occasional histamine-related reaction, marked increases in intra- and postoperative respiratory depression), a suitable alternative was sought but not found among existing opioids. A breakthrough came in 1960, when fentanyl was synthesized, laying the foundation for a better understanding of the structure-activity relationships of narcotic analgesics and stimulating interest in developing compounds with even greater potency and safety margins. Investigators interested in opioid anesthesia began to study fentanyl in animals and then in humans. Fentanyl (50-100 micrograms/kg) with oxygen (100%) was evaluated as an anesthetic in patients undergoing mitral valve and coronary artery surgery. Changes in cardiovascular dynamics with induction doses ranging from 8 to 30 micrograms/kg consisted of small decreases in heart rate and arterial blood pressure. All other cardiovascular variables studied, including cardiac output, remained unchanged, even with additional doses up to 100 micrograms/kg. It was determined that fentanyl had use as a narcotic anesthetic, despite its potential for cardiovascular depression and stimulation, respiratory depression, muscle rigidity, and, occasionally, incomplete anesthesia. Since the introduction of fentanyl, two other potent synthetic opioids have been introduced into clinical practice--sufentanil and alfentanil.
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PMID:The history and development of the fentanyl series. 151 29

Malignant hyperthermia (MH) is a rare genetic myopathy that was first described as a fatal complication of general anesthesia in 1960. It is estimated to affect approximately 1 in 15,000 pediatric patients and 1 in 40,000 adult middle-aged patients. The mode of transmission is genetic: the severest form is autosomal dominant, and the less severe, autosomal recessive. Thus, both men and women can have MH, although there is a slightly higher incidence in the male pediatric population. Malignant hyperthermia is usually triggered by halogenated anesthetic agents with or without depolarizing muscle relaxants. The classic diagnostic triad consists of skeletal muscle rigidity, metabolic acidosis, and elevated body temperature. The definitive diagnosis is suspected susceptible individuals is revealed by exposing an intact muscle fiber to caffeine and halothane in varying concentrations. An abnormal contracture response is hypothesized to be the result of an increase in the release of calcium ion from the sarcoplasmic reticulum in response to neuronal stimulation leading to a hypermetabolic state. The mainstay of treatment is dantrolene, given either prophylactically in susceptible patients or immediately whenever a malignant hyperthermic episode is suspected.
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PMID:Malignant hyperthermia: a review. 156 Feb 93

In humans genetically predisposed to malignant hyperthermia, anesthesia can induce skeletal muscle rigidity, hypermetabolism, and high fever, which, if not immediately reversed, can lead to tissue damage or death. The corresponding condition in swine leads to stress-induced deaths and devalued meat products. Abnormalities in the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum (the ryanodine receptor) have been implicated in the cause of both the porcine and human syndromes by physiological and biochemical studies and genetic linkage analysis. In swine, a single founder mutation in the ryanodine receptor gene (RYR1) can account for all cases of malignant hyperthermia in all breeds, but a series of different RYR1 mutations are likely to be uncovered in human families with MH. Moreover, lack of linkage between malignant hyperthermia and RYR1 in some families indicates a heterogeneous genetic basis for the human syndrome.
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PMID:Malignant hyperthermia. 158 59

In addition to producing antinociception and mild sedation, opiates diminish spontaneous movement and produce muscle rigidity. Examination of the relationship between different opiate effects may lead to a better understanding of the mechanism and sites of action of opiate anesthesia. Previous studies have compared the dose-effect relationships for morphine and fentanyl between antinociception and loss of righting reflex. However, neither muscle rigidity nor lack of spontaneous movement (as measured by catalepsy) has been fully examined or directly compared with either antinociception or loss of righting reflex. This study, therefore, compared five clinically relevant opiate endpoints (antinociception, muscle rigidity, catalepsy, loss of righting reflex, and respiratory depression) using the mu-selective agonist alfentanil in the spontaneously ventilating rat. Rats were randomized to receive alfentanil (0-500 micrograms/kg) subcutaneously. For muscle rigidity, 59 rats had electromyographic activity measured with percutaneous hindlimb electrodes. After alfentanil injection, electromyographic data were recorded for 60 min. For antinociception and catalepsy, 49 rats were studied for 120 min after alfentanil. Catalepsy was measured from the time the rat's forelimbs were placed on a 10-cm-high bar until either limb was removed. Antinociception was studied by measuring tail-flick response to hot (55 degrees C) water. For righting reflex, 40 rats were studied for 120 min. Alfentanil-induced respiratory depression was assessed in 40 rats with indwelling tail arterial catheters. Alfentanil was administered after baseline arterial blood gas measurements, and then additional samples were obtained for 45 min. For each effect, data were converted into quantal responses and were then transformed to probit-log dose-response curves for analysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Elucidation of dose-effect relationships for different opiate effects using alfentanil in the spontaneously ventilating rat. 160 89

Peculiarities of excitation and inhibition in ventral lateral and ventral anterior thalamic neurons were studied in cats with movement disorders (bradykinesia and muscle rigidity) induced by injury of nigrostriatal dopaminergic neurons with neurotoxin N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (5 mg/kg daily, intramuscularly for five days). As was shown in chronic experiments, mean discharge frequency of neurons related to initiation of upper limb movements increased. Excitation of these neurons coincided with movement initiation, flexion and extension becoming more prominent and prolonged as compared with normal animals. In parallel to those changes, bradykinesia developed. In acute experiments performed under ketalar anaesthesia and myorelaxine immobilization it was found that neurotoxin caused a decrease of the inhibition duration and effectiveness in relay and non-relay thalamic motor nuclei neurons. The inhibition deficiency was accompanied by a shortening of latencies of orthodromic responses evoked by red nucleus stimulation. Two days after the last neurotoxin injection, light microscope examination revealed that about 48% of neurons located in the pars compacta of substantia nigra were destroyed. Electron microscopic analysis showed hydropic changes in perykaria and dendrites in most neurons of the substantia nigra pars compacta that are typical of the light type of degeneration. Pathomorphological processes in the synaptic apparatus were also found. The content of dopamine in the caudate nucleus fell to 30% as compared with intact animals. The suggestion is made that the deficiency of inhibition developed in motor thalamic neurons in response to nigrostriatal system destruction results from attenuation of dopamine-modulated direct GABAergic nigrothalamic influences and/or might be connected with increased inhibition of inhibitory interneurons of the same thalamic nuclei conditioned by pallidum disinhibition.
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PMID:Influence of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced injury of dopaminergic nigrostriatal system on movement components of the instrumental reflex and motor thalamic neurons' reactions in the cat. 176 81

Malignant hyperthermia susceptibility (MHS) is a clinically heterogeneous pharmacogenetic disorder characterized by accelerated metabolism, hyperthermia, and frequently muscle rigidity. MHS is elicited by all commonly used potent inhalation anesthetics and depolarizing neuromuscular blockers and remains an important cause of death due to anesthesia. Recent linkage studies suggest a single genetic locus for this disorder on chromosome 19q13.1. The results of our linkage analyses exclude several loci on 19q13.1 as a site for the gene(s) that produces the MHS phenotype in three unrelated families and clearly establish genetic heterogeneity in this disorder. These results are consistent with the hypothesis that the genetic defect that alters thermoregulation may vary in MHS and that clinical variability in the expression of MHS may be explained by genetic heterogeneity.
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PMID:Evidence for genetic heterogeneity in malignant hyperthermia susceptibility. 177 61


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