PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CYCLOSERINE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 109 records · Page 6Linked to original sources

Tetrahydroaminoacridine and D-cycloserine fail to alleviate the water maze spatial navigation defect induced by hippocampal inactivation.

The present study examined the efficacy of single and combined treatment with an anticholinesterase, tetrahydroaminoacridine (i.p.), and a glycine-B site partial agonist, D-cycloserine (i.p.; a positive allosteric modulator of NMDA receptors), in alleviating the deficit in water maze spatial navigation induced by electrolytic lesion of the medial septum or lidocaine infusion into the dorsal hippocampi. In medial septum-lesioned rats, a combination of tetrahydroaminoacridine 3 mg kg(-1) and D-cycloserine 10 mg kg(-1) facilitated acquisition of the water maze test more effectively than either of the drugs alone. Single or combined treatment with tetrahydroaminoacridine 3 mg kg(-1) and D-cycloserine 10 mg kg(-1) had no effect on the water maze deficit induced by hippocampal lidocaine infusion. These results suggest that combined treatment with tetrahydroaminoacridine and D-cycloserine can effectively stimulate water maze spatial navigation, and that functioning of the hippocampus is a prerequisite for this effect.

Anesthetics, Local↗

RS 67333 and D-cycloserine accelerate learning acquisition in the rat.

Various 5-hydroxytryptamine (5-HT) central receptor subtypes have been implicated in cognitive performances. In the present investigation, we studied the effects of the selective 5-HT(4) receptor agonist RS 67333 (1-(4-amino-5-chloro-2-methoxyphenyl)-3-(1-n-butyl-4-piperidinyl)-1-propanone; 1 mg/kg, i.p.) on spatial learning in the rat, and compared them to those of a reference drug, the partial NMDA receptor agonist D-cycloserine (10 mg/kg, i.p.). The effects of these two drugs were evaluated in four protocols which employed the Morris water maze task with various numbers of daily trials and inter-trial intervals (ITI; 4 trials with 30 s ITI; 2 trials with 2 h or 12 h ITI; or one daily trial). In the 2 trial-2 h ITI protocol, rats treated with RS 67333 or D-cycloserine exhibit a reduced mean swim distance during the first days of training when compared to controls. Neither RS 67333 nor D-cycloserine modified the acquisition performances in the 2 trial-12 h ITI or the one daily trial tests or the retention score measured in each protocol. These data suggest that RS 67333 and D-cycloserine can improve the learning rate in a high demand memory task and confirm that selective 5-HT(4) receptor ligands may provide novel approaches for the development of cognitive enhancers.

Aniline Compounds↗

Effects of D-cycloserine and aniracetam on spatial learning in rats with entorhinal cortex lesions.

A great body of behavioural and neurophysiological evidence suggests that excitatory amino acids are involved in mechanisms of learning and memory. Moreover, degeneration of glutamatergic pathways may underlie the cognitive deficits seen in various disorders such as Alzheimer's dementia. As direct stimulation of glutamatergic receptors with agonists may increase the risk of toxicity and accelerate neuropathological changes, a more valid approach seems to be positive modulation of glutamatergic receptors that may reverse the symptoms with a lower risk of excitotoxic effects. Such a possibility offered by partial agonists of the strychnine-insensitive glycine site of the NMDA receptor (Gly-B site) or positive modulators of AMPA receptors, such as aniracetam. In the present study, the effects of d-cycloserine and aniracetam were tested in two animal models of cognitive deficits (entorhinal cortex lesion-induced deficits evaluated in the radial maze and scopolamine-induced amnesia evaluated in passive avoidance test). D-cycloserine (6 mg/kg, for 10 days) had no effect on spatial working memory deficit induced by entorhinal cortex lesions. It did, however, reverse scopolamine-induced deficits in the passive avoidance test when given acutely at the same dose. In contrast, aniracetam (50 mg/kg, for 10 days) produced beneficial effects in the radial maze test in rats with entorhinal cortex lesions, but given at the same dose acutely did not influence scopolamine-induced amnesia. The positive effect of d-cycloserine against scopolamine-induced amnesia may be probably related to the cholinergic-glutamatergic interaction in the hippocampus. The negative data obtained with d-cycloserine in the model of entorhinal cortex lesions-induced cognitive deficits could be taken as a hint that it is probably not suitable for the symptomatological therapy of Alzheimer's disease. The mechanism of positive action of aniracetam cannot be explained on the basis of AMPA receptor modulation, as the dose used (50 mg/kg) is well below that required for the effect at AMPA receptors. Other actions such as peripheral effects or modulation of metabotropic receptors seem more likely.

Animals↗

Determination of cycloserine in human plasma by high-performance liquid chromatography with fluorescence detection, using derivatization with p-benzoquinone.

A new method for determining cycloserine in plasma samples is described. This method is based on the derivatization of cycloserine with p-benzoquinone, a reaction that takes place at the same time as the process of plasma deproteinization due to the presence of ethanol as solvent in the solution of the derivatization reagent. Four derivatives are obtained from this reaction. The main derivative is well correlated with the cycloserine concentration. The ratio between the volumes of the plasma sample and the reagent solution is 1:2 for a p-benzoquinone concentration of 1000 microg/mL. Elution from a C18 column was isocratic, using a mobile phase containing (v/v) 85% aqueous 0.1% formic acid solution, and 15% (v/v) of a mixture of methanol and acetonitrile (1:1), with a flow-rate of 1 mL/min, at 25 degrees C. Determinations by fluorescence detection were achieved with excitation at 381 nm and emission at 450 nm, with a detection limit of 10 ng/mL for an injection volume of 5 microL. This method was validated and applied to the determination of cycloserine in blood plasma samples of several healthy volunteers.

Antibiotics, Antitubercular↗

Discriminative stimulus effects of ethanol: lack of antagonism with N-methyl-D-aspartate and D-cycloserine.

Several drug discrimination studies reported that both competitive and uncompetitive NMDA receptor antagonists substituted for ethanol stimulus in rats. In the present study we examined if compounds that act as agonists at the NMDA receptor complex, D-cycloserine (a partial agonist at the glycine positive modulatory site) and N-methyl-D-aspartate (an agonist at the glutamate binding site), could antagonize the discriminative stimulus effects of ethanol. Rats were trained to discriminate between IP administered 1.0 g/kg of ethanol (10% v/v) and saline under a sweetened milk-reinforced fixed ratio 10 (FR10) schedule of reinforcement. When the animals met the discriminative criteria, antagonism tests were conducted with D-cycloserine (0.3-10.0 mg/kg, IP) and N-methyl-D-aspartate (15.0-60.0 mg/kg, IP). Neither D-cycloserine nor N-methyl-D-aspartate antagonized the ethanol-mediated discriminative stimulus effects. In addition, D-cycloserine (3.0-300.0 mg/kg, IP) did not substitute for ethanol. These results indicate that at least certain agonists at the NMDA receptor complex do not attenuate the ethanol interoceptive cue in the rat.

Alcohol Deterrents↗

Homer 1a gene expression modulation by antipsychotic drugs: involvement of the glutamate metabotropic system and effects of D-cycloserine.

N-methyl-D-aspartate receptor hypofunction has been suggested to play a role in the pathophysiology of schizophrenia. New glutamatergic mechanisms involving metabotropic receptors have been recently proposed to further expand this hypothesis. "Homer" is a family of postsynaptic density proteins functionally and physically attached to glutamate metabotropic receptors. We investigated the activation of the early gene form of Homer after acute treatment with typical or atypical antipsychotic drugs alone or with the adjunction of D-cycloserine. This activation was compared with that of c-fos, considered a putative molecular marker of brain regions activated by antipsychotics. Male Sprague-Dawley rats were treated intraperitoneally with haloperidol (0.8 mg/Kg) or clozapine (15 mg/Kg) alone or with the adjunction of D-cycloserine (20 mg/Kg). Rats were sacrificed ninety minutes after injection and the brains were processed for quantitative in situ hybridization histochemistry. Haloperidol induced a statistically significant increase of Homer both in caudate-putamen and nucleus accumbens compared with controls; clozapine induced Homer significantly only in the accumbens. The adjunction of D-cycloserine attenuated the haloperidol-induced increase of Homer expression in caudate-putamen and nucleus accumbens and attenuated the clozapine-induced increase in the accumbens. The c-fos gene expression was potently induced by haloperidol in caudate-putamen and nucleus accumbens, and by clozapine only in the accumbens. The adjunction of D-cycloserine enhanced c-fos expression only for clozapine in both regions of the forebrain. These results demonstrate a differential involvement of glutamatergic metabotropic system in gene expression modulation induced by typical or atypical antipsychotic drugs and may suggest new molecular basis for the augmentation strategy by a glycine site partial agonist.

Animals↗

Effect of a Y265F mutant on the transamination-based cycloserine inactivation of alanine racemase.

The requirement for d-alanine in the peptidoglycan layer of bacterial cell walls is fulfilled in part by alanine racemase (EC 5.1.1.1), a pyridoxal 5'-phosphate (PLP)-assisted enzyme. The enzyme utilizes two antiparallel bases focused at the C(alpha) position and oriented perpendicular to the PLP ring to facilitate the equilibration of alanine enantiomers. Understanding how this two-base system is utilized and controlled to yield reaction specificity is therefore a potential means for designing antibiotics. Cycloserine is a known alanine racemase suicide substrate, although its mechanism of inactivation is based on transaminase chemistry. Here we characterize the effects of a Y265F mutant (Tyr265 acts as the catalytic base in the l-isomer case) of Bacillus stearothermophilus alanine racemase on cycloserine inactivation. The Y265F mutant reduces racemization activity 1600-fold [Watanabe, A., Yoshimura, T., Mikami, B., and Esaki, N. (1999) J. Biochem. 126, 781-786] and only leads to formation of the isoxazole end product (the result of the transaminase pathway) in the case of d-cycloserine, in contrast to results obtained using the wild-type enzyme. l-Cycloserine, on the other hand, utilizes a number of alternative pathways in the absence of Y265, emphasizing the importance of Y265 in both the inactivation and racemization pathway. In combination with the kinetics of inactivation, these results suggest roles for each of the two catalytic bases in racemization and inactivation, as well as the importance of Y265 in "steering" the chemistry to favor one pathway over another.

Alanine Racemase↗

D-cycloserine, a partial NMDA receptor-associated glycine-B site agonist, enhances reversal learning, but a cholinesterase inhibitor and nicotine has no effect.

The present study examined the efficacy of single and combined treatments with an anticholinesterase, tetrahydroaminoacridine, nicotine and a glycine-B site partial agonist, D-cycloserine, in alleviating the water maze reversal learning defect induced by a medial septal lesion. D-cycloserine (3 and 10 mg/kg) improved reversal learning. Tetrahydroaminoacridine (1 and 3 mg/kg) and nicotine (0.1 and 0.3 mg/kg) had no effect on reversal learning. A combination of tetrahydroaminoacridine 3 mg/kg or nicotine 0.3 mg/kg and D-cycloserine 10 mg/kg was not more effective than D-cycloserine 10 mg/kg alone in improving reversal learning. This suggests that stimulation of NMDA mechanisms may more effectively improve in medial septal-lesioned rats reversal learning processes than stimulation of cholinergic activity.

Alzheimer Disease↗

Inhibition of sphingolipid synthesis by cycloserine in vitro and in vivo.

D- and L-cycloserine were shown to be irreversible inhibitors of the first enzyme of the sphingolipid pathway, 3-ketodihydrosphingosine synthetase, in a study using bacterial and brain microsomal enzymes. L-Cycloserine was shown to be 100 times more inhibitory than the D-isomer for the brain microsomal enzyme in vitro. In vivo, L-cycloserine caused a 70% inhibition of brain microsomal enzyme. Following one injection, enzyme activity recovered 80% of normal after 16 hours. Daily dosages of L-cycloserine on a regimen of intraperitoneal injection for 7 days caused a significant reduction in total brain ganglioside and cerebroside plus sulfatide levels.

Animals↗

L-cycloserine: a potent anticonvulsant.

The L-isomer of 4-amino-3- isoxazolidinone (L-cycloserine), a potent transaminase inhibitor, was tested for its anticonvulsant action. Intraperitoneal injection of 25 mg kg-1 protects the inbred epileptic mouse (DBA/2J) from convulsions. The drug exerts its protective influence 3 h after administration, and its effect subsides gradually thereafter. A normal mouse (CBA/Ca) can be made prone to sound-induced epilepsy by enhancing its cerebral concentrations of Zn2+ and pyridoxal-5'-phosphate (PLP). Prior administration of 25-50 mg kg-1 L-cycloserine counteracts the convulsive effects of these substances. The pretreated animal is resistant to seizures. The concentrations of glutamate and aspartate in the inferior colliculus of the treated animal are diminished, whereas the concentration of gamma-aminobutyrate is enhanced. The time course of the changes in the amino acid concentrations broadly mirrors the changes in seizure susceptibility following the treatment. Proton nuclear magnetic resonance spectra of a mixture containing equimolar concentrations of L-cycloserine, PLP, and ZnSO4 were obtained. From the resonance peaks of such an adduct, we have ascertained that a molecule of L-cycloserine forms an irreversible Schiff base with the 4-aldehyde group of PLP, and this adduct is stabilized by a zinc ion. The significance of this finding for the anticonvulsant action of the drug is discussed.

Amino Acids↗

Comparative inhibition of bacterial and microsomal 3-ketodihydrosphingosine synthetases by L-cycloserine and other inhibitors.

Eleven compounds were examined for their capacity to inhibit the first enzyme of the sphingolipid pathway, 3-ketodihydrosphingosine synthetase. Of these, L-cycloserine was the most potent, affecting both bacterial and brain microsomal enzymes to a significant degree at 0.04 mM. D- and L-cycloserine irreversibly inactivated the enzyme, indicating a suicide substrate mode of action. L-Cycloserine was a more potent inhibitor of the growth of Bacteroides levii than was D-cycloserine, indicating that inhibition of sphingolipid synthesis could be a factor in the growth inhibition.

Animals↗

D-cycloserine uses an active transport mechanism in the human intestinal cell line Caco 2.

In a previous study we have shown that cultured epithelial cell lines can be used to measure the transepithelial passage of antimicrobial agents across the intestine and to obtain information on the mechanisms of transport utilized and predict the bioavailability of the antimicrobial agents after oral administration. In particular, among the drugs investigated, D-cycloserine had been shown to be transported in a polarized manner only in the intestinal cells. In the present work, further characterization of the transport of D-cycloserine in the human intestinal cell line Caco 2 has shown that this occurs in the apical-to-basolateral direction by an active mechanism which is energy dependent but only partially sodium dependent. Competition studies have also indicated that the transport of D-cycloserine occurs via a carrier for imino acids, amino acids with aliphatic side chains (L-Ala, D-Ala, and beta Ala), and L-Trp, L-Tyr, L-Cys, and alpha-amino isobutyric acid. This system may correspond to a proton-dependent system for L-proline and beta-alanine recently described for Caco 2 cells. In contrast with the cephalosporins, which are taken up by the Caco 2 cells via a dipeptide carrier, D-cycloserine transport cannot be inhibited by either cephalexin (a member of the class of cephalosporins) or dipeptides.

Biological Transport, Active↗

Resistance to D-cycloserine in the tubercle bacilli: mutation rate and transport of alanine in parental cells and drug-resistant mutants.

A single transport system was found to accumulate l- and d-alanine, glycine and d-serine in Mycobacterium tuberculosis. The results of inhibition experiments suggested that the antibiotics d-cycloserine and O-carbamyl-d-serine were also transported by the alanine-glycine-d-serine system. A d-cycloserine-resistant permease-competent (d-CS(r)/perm(+)) mutant and a d-cycloserine-resistant permease-defective (d-CS(r)/perm(-)) mutant were isolated. The d-CS(r)/perm(-) mutant was not found to be more resistant to the drug than was the d-CS(r)/perm(+) mutant. The data were consistent with the conclusion that resistance to d-cycloserine in the tubercle bacilli is primarily due to mutations in the gene(s) controlling the enzyme d-alanyl-d-alanine synthetase. The mutation rate was calculated to be about 10(-10) mutations per bacterium per generation.

Alanine↗

Dose-finding trial of D-cycloserine added to neuroleptics for negative symptoms in schizophrenia.

OBJECTIVE: The authors conducted a dose-finding study of D-cycloserine, a partial agonist at the glycine site of the N-methyl-D-aspartate subtype of the glutamate receptor, added to conventional neuroleptics for schizophrenic patients with prominent negative symptoms. METHOD: Nine patients with schizophrenia completed consecutive 2-week trials of placebo and four doses of D-cycloserine. Clinical assessments were videotaped and were scored by a rater who was blind to temporal sequence. RESULTS: D-Cycloserine at a dose of 50 mg/day produced a significant reduction (mean = 21%, SD = 28%) in negative symptoms and significantly improved reaction time as measured by Sternberg's Item Recognition Paradigm, a test mediated in part by prefrontal cortex. CONCLUSIONS: This preliminary evidence suggests that D-cycloserine may improve negative symptoms and cognitive deficits over a narrow dose range when added to conventional antipsychotic agents.

Adult↗

Improved cognition in Alzheimer's disease with short-term D-cycloserine treatment.

OBJECTIVE: Glutamatergic neurotransmission is important for memory and cognition and is severely affected in Alzheimer's disease. D-Cycloserine exhibits partial agonist activity at the glycine site of N-methyl-D-aspartate subtype glutamate receptor, facilitating activation of the receptor and improving cognition and memory. METHOD: Seventeen patients with Alzheimer's disease received a three-phase, double-blind, placebo-controlled trial of 50 mg and 100 mg/day of D-cycloserine. RESULTS: D-Cycloserine was associated with significant improvement in scores on the cognitive subscale of the Alzheimer's Disease Assessment Scale (improvement of 3.0 points) when given at a dose of 100 mg/day. CONCLUSIONS: D-Cycloserine has cognitive benefits for patients with Alzheimer's disease.

Aged↗

Evaluation of cycloserine in the treatment of Alzheimer's disease.

This multicenter study evaluated the efficacy and safety of cycloserine and measured its effects on explicit and implicit memory tests in patients with Alzheimer's disease (AD). Four hundred ten patients with AD, aged 50 years or older, were enrolled in this parallel-group, double-blind, placebo-controlled, randomized trial of 5, 15, or 50 mg cycloserine or placebo twice daily, and 403 entered the double-blind treatment phase. Two hundred sixty-five patients completed the entire 26-week treatment phase. There were no baseline differences among the four treatment groups. Cognitive Drug Research (CDR) efficacy assessments showed no differences between active treatments and placebo from baseline to study weeks 2, 6, 14, or 26. Patients receiving 15 mg of cycloserine improved significantly on one section of an implicit memory test. No differences among treatments were observed for any other assessment scales evaluated. The incidence and severity of adverse events were similar across treatment groups. Cycloserine was well tolerated but did not demonstrate consistent evidence of efficacy during the course of therapy. Higher doses may be necessary to achieve efficacy in the AD population and do not appear to be precluded by the adverse event profile seen in this study.

Aged↗

Bioequivalence assessment of closerin capsule to dura seromycin capsule of cycloserine after a single oral dose administration to healthy male volunteers.

AIM: A bioequivalence study of the closerin capsules to the dura seromycin capsules was conducted. PATIENTS AND METHODS: Twenty-four healthy male Korean volunteers received each medicine at the cycloserine dose of 250 mg in a 2 x 2 crossover study. There was a one-week washout period between the doses. Plasma concentrations of cycloserine were monitored by a high-performance liquid chromatography for over a period of 72 hours after the administration. AUCinf (the area under the plasma concentration-time curve from time zero to time infinity) was calculated by the linear-log trapezoidal method. Cmax (maximum plasma drug concentration) and Tmax (time to reach Cmax) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUCinf and Cmax, and untransformed Tmax. RESULTS: There were no significant differences between the medications in AUCinf and Cmax. The point estimates and 90% confidence intervals for AUCinf (parametric) and Cmax (parametric) were, in point estimate (90% confidence interval), 0.992 (0.950 approximately 1.037) and 1.051 (0.965 approximatly 1.144), respectively, satisfying the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. The corresponding value of Tmax was 0.000 (-0.250 approximatly 0.125). Moreover, the modified Pitman-Morgan's adjusted F test and equal variance test (one-sided) indicated that the 2 medications were comparable in intra- and inter-individual variability in cycloserine bioavailability. CONCLUSION: Therefore, these results indicate that the 2 medications of cycloserine are bioequivalent and, thus, may be prescribed interchangeably.

Administration, Oral↗

Some evidence for interaction of D-cycloserine with DNA.

D-Cycloserine showed a decreased lethality against paraquat-treated E. coli than against non-treated cells. E. coli K12 mutants which were deficient in DNA repair were more sensitive than the wild type strain to D-cycloserine. Furthermore, D-cycloserine caused PM2 DNA cleavage in the presence of Fe2+, and the cleavage was strongly inhibited by singlet oxygen scavengers. These results indicate that D-cycloserine interacts with DNA and an active oxygen species is involved in the interaction.

Cycloserine↗