Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Muscle Relaxants, Central”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Pharmacological studies of 1-(2,3-dimethyl-4-methoxyphenyl)-2-methyl-3-(1-pyrrolidinyl)-1- propanone hydrochloride (AD-2239), a centrally acting muscle relaxant.

Centrally acting muscle relaxant properties of AD-2239 were compared with those of tolperisone, eperisone, diazepam and baclofen. AD-2239 dose-relatedly depressed extensor reflex in urethane-chloralose anesthetized intact and spinal rats, the i.v. potencies being similar to those of tolperisone and eperisone. These effects of AD-2239 were long-lasting. When orally administered, AD-2239 was 4 times more potent than eperisone. Diazepam was without effect on the extensor reflex in spinal rats. AD-2239 depressed the flexor reflex without affecting the patellar reflex in anesthetized cats. Baclofen depressed the latter. When orally administered, AD-2239, in a dose-related manner, depressed the flexor reflex in anesthetized cats, with a potency approximately 8 times that of tolperisone or eperisone. AD-2239 produced a dose-related reduction of anemic decerebrate rigidity (alpha-rigidity) in rats. The potency, at the minimum effective i.v. dose, was 4 times greater than that of tolperisone or eperisone, equal to that of diazepam, and one-half of that of baclofen. AD-2239 neither affected spontaneous electroencephalogram (EEG) nor EEG arousal response in immobilized cats, while the other drugs, at comparatively low doses, depressed them. The results strongly suggest that AD-2239 may have advantages over the existing centrally acting muscle relaxants in the treatment of human clinical spasticity and muscle spasm syndromes.

Animals↗

[Results of electromyographic studies with central muscle relaxants--feasibility of objectivization and standardization].

The following drugs, mostly postulated acting at a supraspinal or spinal level as diazepam, chlormezanone and orphenadrine citrate were proved for their effectiveness in lessening tension of muscles. This was assessed by electromyography recording different neurophysiological phenomenons as mono- and polysynaptic reflex responses (H-reflex and unloading reflex as a result of a suddenly muscle relaxation (= post-reflex inhibition phase/silent period) and tiredness reaction. This investigations were performed on at least 65 patients. The outcomes are: statistical significant increase of the silent period of the unloading reflex under the treatment with diazepam and orphenadrine citrate. Diazepam also extended the time between the initial electric stimulus and H-reflex phenomenon. Evaluating these results it might be obvious that diazepam is acting on supraspinal level and the spinal too, orphenadrine citrate only on the supraspinal one. Chlormezanone showed no effect according to that protocol on all mentioned neurophysiological parameters.

Adult↗

Extension of the jaw opening reflex and effects of a central muscle relaxant (afloqualone) in the rat.

How widely the jaw opening reflex (JOR) extends was examined in the rat. Recording was done in the anterior (AD) and posterior (PD) digastric, sternohyoid (SH) and sternomastoid (SCM) muscles. Electric stimulation was given to the mandibular incisor pulp. Evoked electromyogram (EMG) activities could be recorded in each muscle. The thresholds for JOR increased from AD to SCM. Intravenously administered afloqualone, a centrally acting muscle relaxant, inhibited both JOR and its parallels promptly and dose-dependently. The possible clinical significance in temporomandibular joint dysfunction will be discussed.

Animals↗

[Cleavage and biotransformation of the central muscle relaxant chlormezanone].

Chlormezanone, a chiral centrally acting muscle relaxant, will be cleaved at its S-C-1 bond by an autoprotolytic process. The optimum of chemical stability exists between pH 2 up to pH 9 with a maximum at pH 7.4. The plasma half life at 37 degrees C is 76 h. Enzymes do attack the products of cleavage namely 4-chlorobenzaldehyde and 2-carboxyethane-sulfinic-acid-N-methyl-amide. The main metabolite in urine is 4-chlorohippuric acid in the range of up to 70% of the oral administered dose to humans. No cytochrome P-450 is engaged in the cleavage of the S-C-bond.

Biotransformation↗

[Central muscle relaxant activities of 2-methyl-3-aminopropiophenone derivatives].

In this experiment, we synthetized new 2-methyl-3-aminopropiophenone (MP) derivatives, whose structure is known to have central muscle relaxant activities, and quinolizidine and indan . tetralin derivatives derived from MP by cyclization, and we investigated the central muscle relaxant activity. Among the quinolizidine derivatives, there was a very strong central depressant agent, trans (3H, 9aH)-3-(p-chloro) benzoyl-quinolizidine (HSR-740), and among the indan . tetralin derivatives, there was an excitant agents, trans (1H, 2H)-5-methoxy-3, 3-dimethyl-2-piperidinomethyl indan-1-ol (HSR-719). From the results, these derivatives were not considered to be adequate for central muscle relaxant. Among the MP derivatives, (4'-chloro-2'-methoxy-3-piperidino) propiophenone HCl (HSR-733) and (4'-ethyl-2-methyl-3-pyrrolidino) propiophenone HCl (HSR-770) strongly inhibited the cooperative movement in the rotating rod method using mice, and it exerted almost the same depressant activity on the cross extensor reflex using alpha-chloralose anesthetized rats. However, the inhibitory effects of HSR-733 on the anemic decerebrate rigidity and the rigidity induced by intracollicular decerebration in rats were weaker than those of HSR-770 and eperisone. In spinal cats, at a low dose (5 mg/kg, i.v.), HSR-733 depressed monosynaptic and dorsal root reflex potentials as compared with polysynaptic reflex potentials, and inhibitory effects of HSR-733 on these three reflex potentials were more potent than those of eperisone and HSR-770. Although HSR-770 acts on the spinal cord and supraspinal level on which eperisone has been reported to act, HSR-733 may mainly act on the spinal cord. These results indicate that the MP derivative with a 2-methyl group may be suitable as a central muscle relaxant. HSR-770, which has equipotent muscle relaxant activity to eperisone, exerted strong inhibitory effects on oxotremorine-induced tremor and weak inhibitory effects on spontaneous motor activity in the Animex method using mice, as compared with eperisone.

Animals↗

Synthesis of some indane derivatives of central muscle relaxant and anticonvulsant profiles.

A series of 2,2-bis(hydroxymethyl)indane derivatives 1a-f, 2a-e and 3a-f were synthesized to investigate their central muscle relaxant and anticonvulsant activities. The synthesized compounds 1a-f, 2a-e and 3a-f were found to be devoid of central muscle relaxant activity using meprobamate (100 mg/kg) as a reference standard. However, they showed remarkable anticonvulsant properties in a dose of 80 mg/kg (s.c.) compared with diphenylhydantoin sodium (80 mg/kg) as a reference standard.

Animals↗

[Electroencephalographic effects of chlorphenesin carbamate, a new central muscle relaxant, in rabbits (author's transl)].

Electroencephalographic (EEG) effects of chlorphenesin carbamate were investigated in rabbits with chronic electrode implants, and compared with those of chlormezanone and methocarbamol. Chlorphenesin carbamate (50 mg/kg i.v., 100 mg/kg i.d.) induced a drowsy pattern of spontaneous EEG consisting of high voltage slow waves in the cortex and amygdala, and desynchronization of hippocampal theta waves. Chlormezanone also elicited similar EEG changes but such were much more potent than chlorphenesin carbamate. Methocarbamol showed no effect on spontaneous EEG. Chlorphenesin carbamate caused sedation in this period and muscle relaxation was more potent than that of chlormezanone. The EEG arousal response to auditory stimulation and to electric stimulation of the posterior hypothalamus, centromedian thalamus and mesencephalic reticular formation was slightly depressed by chlorphenesin carbamate. Chlorphenesin carbamate, as with chlormezanone, markedly depressed the limbic afterdischarges elicited by hippocampal stimulation. These EEG effects of chlorphenesin carbamate were qualitatively similar to but much weaker than those of chlormezanone, whereas the muscle relaxant effect of chlorphenesin carbamate was more potent than that of chlormezanone.

Acoustic Stimulation↗

[Important pharmaceutical-chemical characteristics of the central muscle relaxant chlormezanone].

The enantinomers of chlormezanone (1) may be achieved by enantioselective HPLC separation with a yield of 98% using a OD-Daicel column. Both enantiomers bind to human serum albumin (HSA) at pH 7.4 to a range of 11-12%. Binding to the globuline fractions is much less (2-4%, equilibrium dialysis, validation by ultrafiltration). It could be demonstrated by means of 1H-NMR spectroscopy that 1 binds to HSA with the benzene ring as well as with the thiazanone ring. The velocity of racemization could be measured for the first time using a BSA column. The enantiomers undergo racemization at pH 7.4 and 37 degrees C with a halflife of approx. 20.5 h.

Chlormezanone↗