cyclic-gmp and Substance-Withdrawal-Syndrome

Topics: Acetylcholine; Adenine Nucleotides; Animals; Benzodiazepines; Calcium; Calmodulin; Clonidine; Conditioning, Psychological; Cyclic GMP; Dopamine; Drug Tolerance; Enkephalins; Fear; gamma-Aminobutyric Acid; Humans; Methadone; Naloxone; Narcotic Antagonists; Narcotics; Neurons; Norepinephrine; Protein Conformation; Receptors, Opioid; Serotonin; Substance Withdrawal Syndrome

Topics: Alcoholism; Animals; Brain; Cyclic AMP; Cyclic GMP; Drug Tolerance; gamma-Aminobutyric Acid; Humans; Isoquinolines; Rats; Receptors, Cholinergic; Receptors, Opioid; Substance Withdrawal Syndrome; Tetrahydroisoquinolines

The goal of the present study was to examine the effects of N-methyl-aspartate (NMDA) receptor antagonists-memantine and ketamine and the drugs modifying the NO:cGMP pathway-NG-nitro-L-arginine methyl ester (L-NAME) and 7-nitroindazole (7-NI), the endogenous precursor of NO-L-arginine, and the guanylyl cyclase inhibitor-methylene blue (MB) on the development of sensitization to withdrawal signs precipitated after chronic, interrupted treatment with diazepam, a benzodiazepine receptor agonist, in mice. To develop the sensitization, the mice were divided into groups: continuously and sporadically (with two diazepam-free periods) treated with diazepam (15 mg/kg, sc). To precipitate the withdrawal syndrome (clonic and tonic seizures, and death), pentylenetetrazole (55 mg/kg, sc) with the benzodiazepine receptor antagonist, flumazenil (5.0 mg/kg, ip), were administered after the last injection of diazepam or saline. Memantine (2.5, 5.0 mg/kg), and ketamine (2.5, 5.0 mg/kg), L-NAME (100, 200 mg/kg) and 7-NI (20 and 40 mg/kg), L-arginine (250, 500 mg/kg) and MB (5 and 10 mg/kg) were administered ip in sporadically diazepam-treated mice during the diazepam-free periods. Our results indicated that both NMDA receptor antagonists and drugs that inhibit the NO:cGMP pathway, except L-arginine (the endogenous donor of NO), attenuated the diazepam-induced sensitization to withdrawal signs in mice. Thus, NMDA receptors and the NO:cGMP pathway are involved in the mechanisms of sensitization to benzodiazepine withdrawal.

Topics: Animals; Benzodiazepines; Cyclic GMP; Diazepam; Male; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Pentylenetetrazole; Receptors, N-Methyl-D-Aspartate; Signal Transduction; Substance Withdrawal Syndrome

This study was aimed at evaluating the role of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) cascade in mechanisms of morphine dependency formation. Morphine was introduced by intraperitoneal (i.p.) injections in rats twice per day over six days in doses increasing from 10 to 100 mg/kg, For evaluating the role of NO/cGMP cascade, NO synthase inhibitor L-N(G)-Nitroarginine methyl ester (L-NAME) was introduced (10 mg/kg, i.p.) 1 h prior to every injection of morphine. The L-NAME introduction led to enhancement of spontaneous withdrawal syndrome manifestations, which was accompanied by more pronounced decrease in the cGMP levels in midbrain and striatum. It is suggested that the region specific decrease in NO/cGMP cascade signaling activity in the brain can be among mechanisms determining the development of opium dependency.

Topics: Animals; Corpus Striatum; Cyclic GMP; Male; Mesencephalon; Morphine; Morphine Dependence; Narcotics; NG-Nitroarginine Methyl Ester; Nitric Oxide; Rats; Rats, Wistar; Substance Withdrawal Syndrome

Peroxizome proliferator-activated receptor gamma (PPARγ) is highly expressed in the central nervous system where it modulates numerous gene transcriptions. Nitric oxide synthase (NOS) expression could be modified by simulation of PPARγ which in turn activates nitric oxide (NO)/soluble guanylyl-cyclase (sGC)/cyclic guanosine mono phosphate (cGMP) pathway. It is well known that NO/cGMP pathway possesses pivotal role in the development of opioid dependence and this study is aimed to investigate the effect of PPARγ stimulation on opioid dependence in mice as well as human glioblastoma cell line. Pioglitazone potentiated naloxone-induced withdrawal syndrome in morphine dependent mice in vivo. While selective inhibition of PPARγ, neuronal NOS or GC could reverse the pioglitazone-induced potentiation of morphine withdrawal signs; sildenafil, a phosphodiesterase-5 inhibitor amplified its effect. We also showed that nitrite levels in the hippocampus were significantly elevated in pioglitazone-treated morphine dependent mice. In the human glioblastoma (U87) cell line, rendered dependent to morphine, cAMP levels did not show any alteration after chronic pioglitazone administration while cGMP measurement revealed a significant rise. We were unable to show a significant alteration in neuronal NOS mRNA expressions by pioglitazone in mice hippocampus or U87 cells. Our results suggest that pioglitazone has the ability to enhance morphine-dependence and to augment morphine withdrawal signs. The possible pathway underlying this effect is through activation of NO/GC/cGMP pathway.

Topics: Animals; Cell Line, Tumor; Cyclic AMP; Cyclic GMP; Disease Models, Animal; Enzyme Inhibitors; Glioblastoma; Hippocampus; Humans; Hypoglycemic Agents; Male; Mice; Morphine Dependence; Naloxone; Narcotic Antagonists; Nitric Oxide; Nitric Oxide Synthase; Pioglitazone; PPAR gamma; RNA, Messenger; Signal Transduction; Substance Withdrawal Syndrome; Thiazolidinediones; Transfection

This study was undertaken to evaluate the effect of nitric oxide (NO) synthase inhibitors on benzodiazepine withdrawal syndrome in mice and rats. Diazepam withdrawal in mice was read out as intensification of the seizures induced by a subthreshold dose of pentetrazole. In rats, the withdrawal syndrome resulting from chronic administration of diazepam, chlordiazepoxide, clonazepam and temazepam was characterized by audiogenic seizures, hypermotility and weight loss. Administration of the non-selective NO synthase inhibitors N(G)-nitro-L-arginine (L-NOARG) and N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) significantly attenuated the withdrawal syndrome (i.e., pentetrazole-induced seizures) in diazepam-dependent mice. L-NOARG significantly suppressed hypermotility in clonazepam-dependent rats and inhibited the decrease in body weight observed after 12 h of withdrawal in chlordiazepoxide- and clonazepam-dependent rats. Moreover, a clear propensity of L-NOARG to protect benzodiazepine-dependent rats against audiogenic seizures was observed. These findings suggest that the cGMP/NO system may participate in causing the signs of benzodiazepine withdrawal.

Topics: Animals; Benzodiazepines; Body Weight; Cyclic GMP; Enzyme Inhibitors; Male; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Nitroarginine; Rats; Rats, Wistar; Seizures; Substance Withdrawal Syndrome

A role for the cyclic AMP systems in the development of morphine dependence has been previously reported. In this study we investigated whether morphine dependence was inhibited by phosphodiesterase (PDE) 4 inhibitors rolipram and diazepam. Dependence on morphine was induced by a 7-day s.c. implantation of morphine pellets. On day 8, morphine withdrawal was precipitated by an injection of naloxone. In order to determine the effect of rolipram and diazepam rats were injected with these drugs once daily for seven days as well as 30 min before of naloxone injection. When opioid withdrawal was precipitated, an enhanced noradrenaline turnover and increased level of cyclic AMP and cyclic GMP in the hypothalamic paraventricular nucleus (PVN) were observed 30 min after naloxone administration. Moreover, c-Fos expression was induced in the PVN after naloxone-precipitated morphine withdrawal. Co-administration of rolipram or diazepam with morphine during the pre-treatment period, significantly reduced the signs of withdrawal, the enhancement of noradrenaline turnover and the increase in cyclic AMP. However, these inhibitors did not modify either levels of cyclic GMP or c-Fos expression in the PVN. These findings demonstrate that co-administration of rolipram or diazepam with morphine attenuate the withdrawal syndrome and suggest that these compounds may prevent the up-regulation of the cyclic AMP pathway and the associated increase in cyclic AMP level in morphine-withdrawn rats.

Topics: Adaptation, Physiological; Animals; Cyclic AMP; Cyclic GMP; Diazepam; Gene Expression Regulation; Male; Morphine; Neurosecretory Systems; Norepinephrine; Paraventricular Hypothalamic Nucleus; Phosphodiesterase Inhibitors; Pituitary Gland; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Rolipram; Substance Withdrawal Syndrome

To investigate the effect of Cedemex on cAMP and cGMP contents in different brain regions in morphine withdrawal rats precipitated by naloxone.. A physical morphine dependent model of rats was established by subcutaneous injection of morphine in gradually increasing dosage within 7 days. cAMP and cGMP contents of VTA, cortex and hippocampus of the rat brains were determined by radioimmunoassay.. The morphine withdrawal symptoms of rats were relieved significantly by ig Cedemex. Compared with the controls, cAMP content in the region of VTA, cortex and hippocampus of the morphine dependent rats were significantly higher (P < 0.05), while cGMP contents in those regions were significantly lower (P < 0.05). cAMP contents in the area of VTA, cortex and hippocampus of the morphine dependent rats were significantly reduced, while cGMP contents were significantly increased by ig Cedemex.. Cedemex may significantly attenuate the morphine withdrawal symptoms in rats. The mechanism of this effect may be related to adjusting the contents of cAMP and cGMP in some brain regions.

Topics: Animals; Brain; Cerebral Cortex; Cyclic AMP; Cyclic GMP; Drugs, Chinese Herbal; Hippocampus; Morphine; Rats; Substance Withdrawal Syndrome

Alcohol administration is known to alter several brain functions and behaviors in humans and in laboratory animals. One of the targets of ethanol is the mesocorticolimbic dopaminergic reward pathway. We used the "alcohol deprivation effect" test as a rat model of alcohol craving and relapse. The effect is characterized by increased alcohol intake and preference after several weeks of voluntary alcohol consumption followed by a withdrawal phase. The alcohol deprivation effect was found to be considerably reduced by the injection in dopaminergic brain structures of the neuropeptide CNP. This peptide is the most abundant natriuretic peptide in the brain, and signals via an intracellular rise in cyclic GMP. The effect of CNP was observed whether the peptide was injected in situ into the ventral tegmental area or into the prefrontal cortex. It was partially reversed by the injection in the same structures of KT5823, a selective inhibitor of the cGMP-dependent protein kinase. The results indicate that changes of cyclic GMP levels in dopaminergic rat brain areas participate in the neurobiological mechanisms underlying alcohol craving after withdrawal and/or alcohol dependence.

Topics: Alcohol Drinking; Alcohol-Induced Disorders; Animals; Brain; Carbazoles; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Dopamine; Ethanol; Humans; Male; Natriuretic Peptide, C-Type; Neuropeptides; Prefrontal Cortex; Rats; Rats, Wistar; Substance Withdrawal Syndrome; Ventral Tegmental Area

In this study, we investigated whether morphine dependence was inhibited by phosphodiesterase (PDE) 4 inhibitors rolipram and diazepam, since a role for the cyclic AMP systems in the development of morphine dependence was reported. Dependence of morphine was induced by a 7-day s.c. implantation of morphine pellets. Morphine withdrawal was precipitated on day 8 by an injection of naloxone. In order to determine the effect of rolipram or diazepam the animals were injected with these drugs for seven days and 30 min before the administration of naloxone. When opioid withdrawal was precipitated, enhancement of noradrenaline (NA) turnover in the heart was observed 30 min after naloxone administration. Moreover, morphine withdrawal induces Fos expression, increase in cyclic AMP and cyclic GMP levels. Co-administration of rolipram or diazepam with morphine during the pre-treatment period significantly reduces the signs of withdrawal symptoms, the enhancement of NA turnover, the increase in cyclic AMP and the Fos expression. However, these inhibitors did not modify the levels of cyclic GMP. These findings demonstrated that co-administration of rolipram or diazepam with morphine abolish the development of morphine dependence and suggest that these compounds prevent the up-regulation of the cyclic AMP pathway and the associated increase in cyclic AMP level after naloxone administration.

Topics: Animals; Cyclic AMP; Cyclic GMP; Diazepam; Male; Morphine Dependence; Myocardium; Norepinephrine; Normetanephrine; Phosphodiesterase 4 Inhibitors; Phosphodiesterase Inhibitors; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Rolipram; Substance Withdrawal Syndrome

Recent reports to the U.S. Food and Drug Administration Adverse Event Reporting System implicate sildenafil citrate in adverse emotional and aggressive behaviors. Sildenafil citrate (Viagra) is widely prescribed for erectile dysfunction and acts by inhibiting phosphodiesterase Type-5, resulting in accumulation of cyclic-guanosine monophosphate (cGMP). Cyclic-GMP is synthesized by guanylyl cyclase that is directly activated by the messenger molecule, nitric oxide (NO), formed throughout the CNS by the enzyme nitric oxide synthase (NOS). Elevated concentrations of cGMP have been associated with increased aggressive behavior. In addition, the potential effect of cGMP accumulation on NO-mediated behavioral and neuroendocrine function through possible feedback mechanisms remains unspecified; however, neuronal NOS (nNOS) inhibition by pharmacologic agents or ablation of the gene encoding nNOS increases aggressive behavior in male mice. We tested the hypothesis that sildenafil citrate may increase aggression via its actions on cGMP and potential feedback inhibition of NO concentrations. Male C57BL/6 mice were injected with saline vehicle (0), 2, 5, 8, or 10 mg/kg of sildenafil citrate thrice weekly for 4 weeks. Latency to display aggressive behavior, frequency, and duration of aggressive behavior were recorded during neutral-arena aggression tests. No change in agonistic behavior was observed in mice during treatment with sildenafil citrate. However, sildenafil-treated mice given the highest dose were generally more aggressive 1 week post-cessation of drug treatment as compared to vehicle-treated mice. Additional investigation into potential withdrawal effects or abuse doses seems warranted.

Topics: Aggression; Animals; Cyclic GMP; Least-Squares Analysis; Male; Mice; Mice, Inbred C57BL; Piperazines; Purines; Sildenafil Citrate; Substance Withdrawal Syndrome; Sulfones; Time Factors; Vasodilator Agents

The main objective of the present study is to investigate the possible effects of chronic ethanol consumption and ethanol withdrawal on cyclic guanosine 3', 5'-monophosphate (cGMP) levels in cerebral cortex, striatum, hippocampus and hypothalamus of rat brain. Ethanol was given to female Wistar rats (225-270g) by a liquid diet for 21 days. cGMP levels were measured in respective brain regions using an EIA kit at 7th, 14th and 21st days of ethanol ingestion and at 6th and 24th h of ethanol withdrawal. cGMP levels in cortex, striatum and hippocampus but not hypothalamus were found significantly increased at 14th and 21st days of ethanol consumption. The most prominent increase was observed in striatal tissues (approximately 350%). cGMP levels of striatum and hippocampus were still remaining significantly high at 6th h of ethanol withdrawal. Blood ethanol levels were found as 115.60, 50.0 and 7.0mg/dl just before and after 6 and 24h of ethanol withdrawal, respectively and audiogenic seizures also occurred at 6th h of ethanol withdrawal with an incidence of 75% in individual parallel groups. Our results suggest that changes of cGMP levels in cerebral cortex, striatum and hippocampus might participate in the mechanism of ethanol dependence and withdrawal in rats.

Topics: Animals; Brain; Cyclic GMP; Ethanol; Female; Rats; Rats, Wistar; Substance Withdrawal Syndrome

Although the phenomenon of opioid tolerance and dependence has been widely investigated, neither opioid nor non-opioid mechanisms are completely understood. In view of the modulation of 5-HT transport into presynaptic terminals in the brain by nitric oxide (NO) via cGMP, and the existence of a tonic 5-HTergic inhibition of dopamine release, the present study investigated the effect of fluoxetine, a selective serotonin reuptake inhibitor, and NO modulators L-N(G)-nitroarginine methyl ester (L-NAME; NO synthase inhibitor) and L-Arginine (substrate for nitric oxide synthase) alone or in combination against morphine tolerance and dependence. Animals developed tolerance to the antinociceptive effect of morphine (10 mg/kg s.c. twice daily) on day 3 and the degree of tolerance was further enhanced on days 9 and 10. The development of tolerance to the antinociceptive effect of morphine was delayed by prior administration of fluoxetine (10 mg/kg i.p, twice daily for 9 days) and L-NAME (10 mg/kg i.p. twice daily for 9 days) alone or in combination. It was accentuated by L-Arginine (50 mg/kg i.p. twice daily for 9 days) alone or in combination with fluoxetine (10 mg/kg i.p. twice daily for 9 days). Similarly, fluoxetine (10 mg/kg i.p.) or L-NAME (10 mg/kg i.p.), when administered acutely on day 10, reversed morphine-induced tolerance. L-Arginine (50 mg/kg i.p.) however, when administered acutely on day 10, accentuated morphine tolerance. Fluoxetine (10 mg/kg i.p. twice daily for 9 days) suppressed the development of morphine dependence as assessed by naloxone (2 mg/kg i.p.)-precipitated withdrawal jumps. This suppression of dependence was potentiated by L-NAME (10 mg/kg i.p. twice daily for 9 days) and reversed by L-Arginine (50 mg/kg i.p. twice daily for 9 days), respectively. Acute administration of the respective drugs on day 10 modulated morphine dependence in a similar fashion. L-Arginine also reversed fluoxetine-induced weight loss in morphine-dependent animals. The present study demonstrated that fluoxetine suppressed the dependence and development of tolerance to the antinociceptive effect of morphine. Fluoxetine-induced suppression was potentiated by L-NAME and accentuated by L-Arginine. The results therefore suggest that a complex phenomenon such as morphine tolerance and dependence might involve close interplay of the NO-c GMP/5-HT/DA receptor system. To the best of the authors' knowledge, this is the first report to suggest targeting this cascade for ame

Topics: Animals; Arginine; Body Weight; Cyclic GMP; Depression, Chemical; Diarrhea; Dopamine; Drug Interactions; Drug Tolerance; Female; Fluoxetine; Male; Mice; Morphine Dependence; Naloxone; Narcotic Antagonists; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Selective Serotonin Reuptake Inhibitors; Serotonin; Substance Withdrawal Syndrome

Inhaled nitric oxide (NO) is increasingly used in the treatment of pulmonary hypertension, despite its potential toxicity and the risk of life-threatening rebound pulmonary hypertension upon its discontinuation. We investigated whether i.v. dipyridamole, a cGMP phosphodiesterase inhibitor, increased the effects of inhaled NO and prevented rebound pulmonary hypertension. In 14 anesthetized and mechanically ventilated piglets, pulmonary hypertension was induced with U-46619, a thromboxane A(2) analogue. Response to NO and rebound pulmonary hypertension were evaluated without and with i.v. dipyridamole. Low-dose dipyridamole (10 micro g/kg/min) increased cardiac output and augmented the effects of inhaled NO on pulmonary vascular resistance, with marginal additive effect on mean pulmonary artery pressure. Pulmonary vascular resistance decreased from 904 to 511 (20 parts per million NO) (p < 0.0005) and 358 dyne s cm(-5) (20 parts per million NO + dipyridamole) (p < 0.001 versus NO alone), and mean pulmonary artery pressure decreased from 29.0 to 20.5 (p < 0.0001) and 19.3 mm Hg (NS versus NO), respectively. Mean arterial pressure decreased from 85 to 74 mm Hg (dipyridamole + NO) (p < 0.01). High-dose dipyridamole (100 micro g/kg/min) with inhaled NO reduced pulmonary vascular resistance to 334 dyne s cm(-5) but also decreased mean arterial pressure to 57 mm Hg. Eight piglets developed rebound pulmonary hypertension. Two died of acute right ventricular failure and, in five, rebound pulmonary hypertension was prevented by low-dose dipyridamole. In conclusion, low-dose i.v. dipyridamole augments the effects of inhaled NO on right ventricular afterload with moderate changes in systemic hemodynamics, and can prevent rebound pulmonary hypertension.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; 3',5'-Cyclic-GMP Phosphodiesterases; Administration, Inhalation; Animals; Cyclic GMP; Cyclic Nucleotide Phosphodiesterases, Type 5; Dipyridamole; Drug Synergism; Hypertension, Pulmonary; Injections, Intravenous; Nitric Oxide; Phosphodiesterase Inhibitors; Phosphoric Diester Hydrolases; Recurrence; Substance Withdrawal Syndrome; Swine; Vascular Resistance

The present work studied neurochemical changes in rat premotor cortex 30 min, 1 and 5 days after withdrawal from cocaine repeated administration (20 and 30 mg/kg, intraperitoneally, daily for 7 days). Binding assays were performed in 10% homogenates, and ligands used were [(3)H]-N-methylscopolamine, [(3)H]-SCH 23390, and [(3)H]-spiroperidol for muscarinic, D(1)- and D(2)-like receptors, respectively. Levels of cyclic AMP (cAMP) and cyclic guanosine monophosphate (cGMP) were determined using a commercial kit. Scatchard analyses of muscarinic receptors showed an upregulation after 1 and 5 days withdrawal. While D(2)-like receptors were upregulated at all withdrawal periods, D(1)-like receptors were upregulated only at the 30 min withdrawal, and returned to normal levels after 1 day of the last injection. In relation to cAMP levels, the repeated cocaine administration, 1 day after the last injection produced a decrease (around 26%) with both doses, while a 67% increase was seen in cGMP levels with the 30 mg/kg dose. These findings indicate lasting neurochemical changes in premotor cortex caused by cocaine which remained after different withdrawal periods.

Topics: Animals; Binding, Competitive; Cocaine; Cocaine-Related Disorders; Cyclic AMP; Cyclic GMP; Dose-Response Relationship, Drug; Drug Administration Schedule; Male; Motor Cortex; Neurons; Radioligand Assay; Rats; Rats, Wistar; Receptors, Dopamine; Receptors, Dopamine D1; Receptors, Dopamine D2; Receptors, Muscarinic; Substance Withdrawal Syndrome; Up-Regulation

Previous studies have shown that activation of N-methyl-D-aspartate (NMDA) receptors and formation of nitric oxide (NO) contributes to the hyperactivity of locus coeruleus (LC) noradrenergic neurons and behavioural symptoms seen during opioid withdrawal. However, the role of soluble guanylyl cyclase (sGC), the 'physiological' target of NO, in this phenomenon is unclear. In this study, the effect of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a highly selective sGC inhibitor, on the naloxone-precipitated morphine withdrawal was examined using differential normal pulse voltammetry (DNPV) to measure LC activity, in vivo microdialysis to measure glutamate/aspartate release response, and behavioural assessment to evaluate withdrawal symptoms. In halothane-anaesthetized rats, acute intracerebroventricular (i.c.v.) morphine (10 microg) reduced the catecholamine oxidation current (CA.OC) (54.5+/-4.9% of baseline). Naloxone (2 mg/kg, i.v.) reversed this action of morphine and produced a rebound increase in CA.OC (136.1+/-6.0% of baseline), representing acute morphine withdrawal. Administration of ODQ (200 nmol, i.c.v.) blocked this response without affecting acute morphine action. In animals chronically treated with morphine (15 microg/microl/h, i.c.v., 5 days), naloxone significantly increased both the CA.OC signal (270.0+/-19.6% of baseline) and the release of L-glu (193+/-30.4%) and L-asp (221.5+/-28.4%) above baseline. These responses were attenuated in animals pretreated with ODQ. In unanaesthetized chronic morphine dependent rats, ODQ treatment suppressed the signs of withdrawal precipitated by naloxone (10 mg/kg). Taken together, the results of this study suggest that sGC plays an intermediary role in the genesis of LC neuronal hyperactivity and behavioural signs of morphine withdrawal.

Topics: Analgesics, Opioid; Animals; Behavior, Animal; Cyclic GMP; Enzyme Inhibitors; Excitatory Amino Acids; Guanylate Cyclase; Locus Coeruleus; Male; Morphine; Naloxone; Narcotic Antagonists; Opioid-Related Disorders; Oxadiazoles; Quinoxalines; Rats; Rats, Sprague-Dawley; Substance Withdrawal Syndrome

The irreversible nature of haloperidol-induced tardive dyskinesia suggests a neurotoxic etiology, although the causes are unknown. Since nitric oxide demonstrates neurotoxic as well as neuroprotectant properties, and antipsychotics can inhibit nitric oxide (NO) synthase in vitro, this study investigates the NO-cGMP pathway as a pre-determining factor in chronic haloperidol-associated dyskinesia in rats. Sprague-Dawley rats were administered either water, oral haloperidol (0.25 mg/kg per day po), the guanylyl cyclase-nNOS inhibitor, methylene blue (MB; 5 mg/kg per day ip) or haloperidol plus MB for 3 weeks. In a second protocol, rats received water or haloperidol orally for 17 weeks, followed by 3 weeks withdrawal. Either saline (ip) or MB (ip) was administered for 3 weeks prior to haloperidol withdrawal. Vacous chewing movements (VCMs) were continuously monitored, followed by the determination of serum nitrogen oxides (NO(x)) and striatal cGMP at week 20. Chronic haloperidol engendered significant VCMs, with acute withdrawal resulting in significantly reduced plasma NO(x) and striatal cGMP. Furthermore, NO(x) and cGMP suppression was amplified by pre-withdrawal MB administration. Sub-acute haloperidol similarly induced incremental VCMs, but without effect on NO(x) or cGMP. However, haloperidol plus MB also induced significantly greater VCMs with decreased cGMP compared to haloperidol alone. Thus, NO(x)-cGMP inhibition persists pronounced after long-term haloperidol treatment and withdrawal. MB potentiation of these effects suggests that haloperidol inhibits a NO-dependent neuro-protective response to oxidative stress in the striatum that may pre-determine TD development.

Topics: Animals; Antipsychotic Agents; Brain Mapping; Corpus Striatum; Cyclic GMP; Dyskinesia, Drug-Induced; Haloperidol; Male; Motor Activity; Nitric Oxide; Nitric Oxide Synthase; Rats; Rats, Sprague-Dawley; Substance Withdrawal Syndrome

Topics: 3',5'-Cyclic-GMP Phosphodiesterases; Administration, Inhalation; Cyclic GMP; Female; Humans; Hypertension, Pulmonary; Infant; Infant, Newborn; Nitric Oxide; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Substance Withdrawal Syndrome; Sulfones

Life-threatening increases in pulmonary vascular resistance have been noted on acute withdrawal of inhaled nitric oxide (NO), although the mechanisms remain unknown. In vitro data suggest that exogenous NO exposure inhibits endothelial NO synthase (NOS) activity. Thus the objectives of this study were to determine the effects of inhaled NO therapy and its acute withdrawal on endogenous NOS activity and gene expression in vivo in the intact lamb. Six 1-mo-old lambs were mechanically ventilated and instrumented to measure vascular pressures and left pulmonary blood flow. Inhaled NO (40 ppm) acutely decreased left pulmonary vascular resistance by 27. 5 +/- 4.7% (P < 0.05). This was associated with a 207% increase in plasma cGMP concentrations (P < 0.05). After 6 h of inhaled NO, NOS activity was reduced to 44.3 +/- 5.9% of pre-NO values (P < 0.05). After acute withdrawal of NO, pulmonary vascular resistance increased by 52.1 +/- 11.6% (P < 0.05) and cGMP concentrations decreased. Both returned to pre-NO values within 60 min. One hour after NO withdrawal, NOS activity increased by 48.4 +/- 19.1% to 70% of pre-NO values (P < 0.05). Western blot analysis revealed that endothelial NOS protein levels remained unchanged throughout the study period. These data suggest a role for decreased endogenous NOS activity in the rebound pulmonary hypertension noted after acute withdrawal of inhaled NO.

Topics: Administration, Inhalation; Animals; Cyclic GMP; Endothelium, Vascular; Enzyme Inhibitors; Gene Expression; Hypertension, Pulmonary; Nitric Oxide; Nitric Oxide Synthase; Pulmonary Circulation; Sheep; Substance Withdrawal Syndrome; Time Factors; Vascular Resistance

Female Sprague-Dawley rats were maintained on a diet of powdered food containing barbital for 8 weeks before the drug was abruptly withdrawn. Twenty-four hours later both barbital-dependent and control rats were injected intracerebroventricular (i.c.v.) with saline or one of four doses of kainic acid (KA) or in a separate experiment with saline or one of three doses of N-methyl-D-aspartic acid (NMDA) or of quisqualic acid (QA). After 4.5 min, the animals were killed by focused microwave irradiation, and the cerebella were collected. The levels of cyclic guanosine 3',5' monophosphate (cGMP) were markedly elevated in the cerebella of barbital-withdrawn rats when compared to controls. When compared to saline treatment, KA, at all dosages, resulted in a significantly greater elevation of cerebellar cGMP in the barbital-withdrawn rats than was induced by drug withdrawal alone. Only the two higher dosages of KA produced a significant elevation of this parameter in the control rats. Unlike KA, neither QA or NMDA produced any greater elevations of cGMP in barbital withdrawn rats than were induced by drug withdrawal alone. These collective results suggest that there is an increase in the response to KA but not QA or NMDA following the withdrawal of barbital from dependent rats.

Topics: Animals; Aspartic Acid; Barbital; Barbiturates; Cerebellum; Cyclic GMP; Dose-Response Relationship, Drug; Female; Injections, Intraventricular; Kainic Acid; N-Methylaspartate; Neuromuscular Depolarizing Agents; Oxadiazoles; Quisqualic Acid; Rats; Rats, Inbred Strains; Substance Withdrawal Syndrome; Substance-Related Disorders

Topics: Animals; Anti-Anxiety Agents; Anticonvulsants; Behavior, Animal; Benzodiazepinones; Cats; Conflict, Psychological; Cyclic GMP; Diazepam; Dogs; Flunitrazepam; Mice; Rats; Receptors, GABA-A; Saimiri; Substance Withdrawal Syndrome

Female Sprague-Dawley rats were maintained on a diet of barbital for 8 weeks, a period of time previously shown to result in tolerance to and dependence on the drug. After completing this course, the barbital was abruptly withdrawn and the selective antagonist of N-methyl-d-aspartate (NMDA), 2-amino-7-phosphonoheptanoic acid (APH), or saline was infused intracerebroventricularly over 48 hr. Control rats which had not received barbital, were similarly infused with either saline or APH. All animals were observed for 12-48 hr following the withdrawal of the barbital; spontaneous convulsions, previously reported to be numerous and severe after withdrawal of the drug, were counted and graded according to severity. Forty-eight hr after withdrawal of barbital, the rats were killed by focussed microwave irradiation and cerebellae were collected for later determination of levels of cGMP. Nine convulsions occurred in 29 rats withdrawn from barbital and infused intracerebroventricularly with APH, this contrasted markedly with 61 convulsions seen in 29 animals withdrawn from the drug and infused with saline. There was a 3-fold elevation of levels of cGMP in the saline-infused, barbital-withdrawn rats when compared to control rats infused with saline. This evaluation was markedly, although not completely, prevented by the intracerebroventricular infusion of APH. These data provide evidence that dicarboxylic amino acid pathways, specifically those acting through NMDA receptors, are involved in seizure activity seen following abrupt abstinence from barbital.

Topics: 2-Amino-5-phosphonovalerate; Amino Acids; Animals; Aspartic Acid; Barbital; Barbiturates; Cerebellum; Cyclic GMP; Female; N-Methylaspartate; Rats; Rats, Inbred Strains; Seizures; Substance Withdrawal Syndrome; Substance-Related Disorders

Studies of tissue culture cells and tissue slices have implicated the nucleotides, cyclic AMP and cyclic GMP, in the mechanism of action of opiates. However, there are little in vivo data to corroborate this hypothesis. We addicted rats to the synthetic opiate, methadone, by providing the drug in their drinking water (dosage 2.1 mg./kg./day). The two cyclic nucleotides were measured in four brain areas which contain a high concentration of opiate receptors: amygdala, neostriatum, periventricular grey, and thalamus. Data were obtained after acute exposure of the drug (1 day), tolerance (35 days), withdrawal (35 days on drug then 1 day off drug), and readjustment (35 days on drug then 21 days off drug). Cyclic GMP levels were low (0.03 pmol./mg. tissue) in the four regions and did not differ significantly during the experiment. Cyclic AMP levels were higher (1-3 pmol./mg.) and fluctuated consistently in the four regions. After acute methadone treatment, there was a reduction in cyclic AMP, which continued at lower levels after tolerance. One day of withdrawal led to increased cAMP, which rose to near control levels. After readjustment, the levels were reduced. These data indicate an involvement of cyclic AMP in the addiction and withdrawal processes in the intact animal.

Topics: Amygdala; Animals; Brain; Cerebral Ventricles; Corpus Striatum; Cyclic AMP; Cyclic GMP; Male; Methadone; Rats; Substance Withdrawal Syndrome; Substance-Related Disorders; Thalamus; Tissue Distribution

Female Sprague-Dawley rats were placed on a 6-week barbital feeding regimen, previously documented to result in drug tolerance and dependence. Groups of animals were sacrificed on the 2nd and 5th day of each week, up to week 5, or at various time points following drug withdrawal. Cerebellae and cerebral cortices were collected for cyclic GMP (cGMP) measurements. Initial suppressions of cGMP were seen in both the cerebellum and cerebral cortex during early weeks of the feeding regimen. These gradually returned essentially to control levels by the end of 5 weeks, a finding consistent with the development of tolerance to chronic barbiturates in the cGMP system. Barbital was withdrawn after 6 weeks of chronic administration. Four hours after withdrawal, a dramatic elevation of cerebellar cGMP was seen. This elevation was coincident with a significant decline in serum barbital levels and preceded the onset of weight loss, spontaneous seizures and locomotor depression. The elevation of cGMP was less dramatic but still apparent at 72 hr postwithdrawal when all other evaluated parameters had returned to control values. Alterations of cGMP during chronic barbital treatment and subsequent to abrupt barbital withdrawal may reflect aberrations in the function of neurotransmitter pathways involved in regulating cGMP in the cerebellum. Further, the elevation of cGMP after barbiturate withdrawal may itself play a functional role in the manifestation of barbital abstinence.

Topics: Animals; Barbital; Barbiturates; Cerebellum; Cerebral Cortex; Cyclic GMP; Drug Tolerance; Female; Humans; Motor Activity; Rats; Rats, Inbred Strains; Substance Withdrawal Syndrome

Topics: Adult; Aged; Cyclic AMP; Cyclic GMP; Ethanol; gamma-Aminobutyric Acid; Humans; Male; Middle Aged; Norepinephrine; Psychoses, Alcoholic; Substance Withdrawal Syndrome

Topics: Adult; Alcoholism; Brain; Cyclic AMP; Cyclic GMP; Female; Homovanillic Acid; Humans; Hydroxyindoleacetic Acid; Male; Methoxyhydroxyphenylglycol; Middle Aged; Substance Withdrawal Syndrome

Topics: Adenine Nucleotides; Animals; Brain; Creatine; Cyclic AMP; Cyclic GMP; Ethanol; gamma-Aminobutyric Acid; Glycolysis; Humans; Ketone Bodies; Male; NAD; Phosphocreatine; Rats; Substance Withdrawal Syndrome

The selectivity and specificity of fenmetozole (DH-524) [2(3,4-dichlorophenoxy-methyl)2-imidazole HCl] as an antagonist of the actions of ethanol were examined. Fenmetozole (15--30 g/kg) reduced ethanol-induced impairment of the aerial righting reflex without changing blood or brain ethanol content, indicating that the antagonistic actions of fenmetozole were not de to change in the pharmacokinetics of ethanol. Since fenmetozole also reduced aerial righting reflex impairment due to phenobarbital, chlordiazepoxide, and halothane, this action of fenmetozole was not specific to ethanol. In mice, both the ethanol-induced increase in locomotor activity at 2.0 g/kg and the decrease caused by 4.0 g/kg were antagonized by fenmetozole. In addition, fenmetozole attenuated the ethanol-induced reduction in cerebellar cyclic guanosine monophosphate (cGMP) content, but the drug also significantly elevated cGMP levels in this tissue when given alone. Fenmetozole did not alter ethanol-induced increases in punished drinking in a conflict test, except at a high dose which alone decreased both punished and unpunished responding. Fenmetozole also failed to precipitate ethanol withdrawal-like reactions when given to physically-dependent, intoxicated rats. Thus, the antagonistic action of fenmetozole against ethanol would not seem to be related to a specific receptor interaction but rather may be the result of a physiological antagonism.

Topics: Acoustic Stimulation; Animals; Behavior, Animal; Brain; Cerebellum; Conflict, Psychological; Cyclic AMP; Cyclic GMP; Ethanol; Humans; Imidazoles; Locomotion; Male; Phenyl Ethers; Rats; Reflex; Seizures; Substance Withdrawal Syndrome

Rats exposed to chronic intake of sodium barbital maintained high circulating levels of barbital in blood and brain and exhibited increased sensitivity ot audiogenic convulsions during the withdrawal period. Levels of gamma-aminobutyric acid (GABA), glutamate, guanosine 3',5'-monophosphate (cyclic GMP) and adenosine 3',5'-monophosphate (cyclic AMP) were measured in selected brain regions after sacrifice with high power microwave inactivation. Cyclic GMP during chronic barbital administration was significantly lower than controls in most brain regions, especially the hindbrain. During the withdrawal period cyclic GMP in the cerebellum was significantly increased, while returning at least to control levels in all other regions. GABA throughout the brain tended to be reduced during barbital dependence, while cyclic AMP and glutamate levels remained unchanged in all groups. These results indicate a possible role for cyclic GMP in the mediation of the central nervous system response during barbiturate dependence and withdrawal.

Topics: Acoustic Stimulation; Animals; Barbital; Barbiturates; Brain; Cyclic AMP; Cyclic GMP; gamma-Aminobutyric Acid; Glutamates; Humans; Male; Rats; Seizures; Substance Withdrawal Syndrome; Substance-Related Disorders; Time Factors

A previous finding from our laboratory, that a single dose of ethanol depletes cerebellar cyclic guanosine 3':5'-monophosphate (cGMP), has now been extended to an investigation of the effects of acute and chronic ethanol treatment of cGMP levels in six areas of the rat brain. Rats were either gavaged with a single dose of ethanol (6g/kg) or rendered ethanol-dependent with 11 to 15 g/kg/day in 3 to 5 fractions over a 4-day period. A single dose of ethanol depleted cGMP levels in only five areas of the brain studied. In the two areas in which a time course of the response was determined, the caudate nucleus and cerebral cortex, cGMP depletion was maximal 1 hour after ethanol administration when blood ethanol concentrations were highest. cGMP levels returned to control values as blood ethanol was eliminated. Inethanol-dependent animals still intoxicated, cGMP was reduced but not to the same magnitude in the cerebellum and brain stem when compared with the response obtained after a single dose at equivalent blood ethanol concentrations. During the ethanol withdrawal syndrome cGMP levels had returned to control vlaues. The data suggest that cBMP depletion may play a role in ethanol-induced intoxication and that tolerance to this effect develops concurrently with behavioral tolerance.

Topics: Alcoholic Intoxication; Alcoholism; Animals; Brain; Brain Chemistry; Cyclic GMP; Ethanol; Guanylate Cyclase; Humans; Male; Phosphoric Diester Hydrolases; Rats; Substance Withdrawal Syndrome; Time Factors

Topics: Analgesics, Opioid; Animals; Brain; Caffeine; Cyclic AMP; Cyclic GMP; Drug Tolerance; Humans; Ileum; Models, Biological; Morphine; Neurons; Rats; Receptors, Opioid; Substance Withdrawal Syndrome; Substance-Related Disorders

The effect of ethanol on cyclic nucleotide levels was investigated in male Sprague-Dawley rats. The rats were sacrificed by microwave irradiation, the brains were divided into four areas, and cyclic nucleotides were measured by radioimmunoassays. Administration of a single dose of ethanol per os produced a dose-dependent decrease of adenosine 3':5'-monophosphate (cyclic AMP) in cerebral cortex, cerebellum, pons and medulla oblongata while guanosine 3':5'-monophosphate (cyclic GMP) was decreased in all brain areas. Dependence on ethanol was induced by three daily administrations of ethanol p.o. for 7 days. The last dose of ethanol did not produce any decrease of cyclic AMP levels while the decrease of cyclic GMP levels was still present. During ethanol withdrawal cyclic AMP levels increased in cerebral cortex, pons and medulla oblongata and did not change in cerebellum. Changes of cyclic AMP in subcortex were more complex. Cyclic GMP levels increased during ethanol withdrawal in cerebellum, pons and medulla oblongata and did not change in cerebral cortex and subcortex. These results indicate that changes of cyclic nucleotides might participate in the mechanism of ethanol dependence and withdrawal.

Topics: Animals; Behavior, Animal; Brain Chemistry; Cerebellum; Cerebral Cortex; Cyclic AMP; Cyclic GMP; Ethanol; Humans; Male; Medulla Oblongata; Pons; Rats; Substance Withdrawal Syndrome; Substance-Related Disorders; Time Factors

Topics: Aminobutyrates; Animals; Apomorphine; Brain Chemistry; Cerebellum; Corpus Striatum; Cyclic GMP; gamma-Aminobutyric Acid; Humans; Male; Morphine Dependence; Rats; Rats, Inbred Strains; Substance Withdrawal Syndrome

An increase in mouse cerebellar C-GMP levels during acute morphine treatment was observed, which was possibly related to the decrease in C-GMP phosphodiesterase levels also observed in acute treatment. Chronic treatment lowered C-GMP levels as did abrupt withdrawal without naloxone.

Topics: Animals; Cerebellum; Cyclic GMP; Guanylate Cyclase; Humans; Male; Mice; Morphine; Morphine Dependence; Naloxone; Phosphoric Diester Hydrolases; Substance Withdrawal Syndrome

Topics: Animals; Cerebellum; Cyclic GMP; Dose-Response Relationship, Drug; Drug Tolerance; Humans; Male; Morphine; Naloxone; Pentobarbital; Rats; Substance Withdrawal Syndrome; Time Factors

Topics: Animals; Brain; Brain Chemistry; Bucladesine; Cyclic AMP; Cyclic GMP; Depression, Chemical; Disease Models, Animal; Drug Implants; Humans; Male; Morphine; Morphine Dependence; Motor Activity; Naloxone; Phosphoric Diester Hydrolases; Rats; Stimulation, Chemical; Substance Withdrawal Syndrome

Topics: Adrenergic beta-Antagonists; Animals; Cyclic AMP; Cyclic GMP; Cycloheximide; Drug Tolerance; Humans; Mice; Morphine; Naloxone; Phosphodiesterase Inhibitors; Substance Withdrawal Syndrome; Substance-Related Disorders; Theophylline

Topics: Animals; Bucladesine; Cyclic GMP; Ethanol; Head; Humans; Imidazoles; Methyltyrosines; Mice; Mice, Inbred Strains; Movement; Nucleotides; Serotonin; Substance Withdrawal Syndrome; Theophylline; Time Factors