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Luigi Pulvirenti

Publications and source records attributed to Luigi Pulvirenti.

6 recordsLinked to original sources

Effects of terguride, ropinirole, and acetyl-L-carnitine on methamphetamine withdrawal in the rat.

Withdrawal from psychostimulants, including methamphetamine, induces a depressive state associated with lethargy, dysphoria, hyperphagia and psychomotor retardation. Previous work with repeated administration of amphetamine in rats has shown that amphetamine withdrawal produces decreased motivation to work for a non-drug reward, and this withdrawal is reversed by administration of a dopamine partial agonist. The purpose of the present study was to examine decreased motivation to work for a non-drug reward during methamphetamine withdrawal and explore the effects of a dopamine agonist, dopamine partial agonist, and indirect monoamine agonist on methamphetamine withdrawal. During withdrawal from repeated methamphetamine administration, rats showed reduced responding for a sweet solution in a progressive-ratio schedule of reinforcement, and this effect was significantly more pronounced than previously observed with amphetamine. Repeated systemic treatment with the dopamine partial agonist terguride (0.2 and 0.4 mg/kg, i.p., twice daily), the full dopamine agonist ropinirole (1 mg/kg, i.p., twice daily), and acetyl-L-carnitine (60 and 100 mg/kg, i.p.), a compound with a potential antidepressant effect, during methamphetamine withdrawal restored responding for the sweet solution, suggesting that these drugs may represent potential therapeutic strategies for the treatment of methamphetamine addiction during the withdrawal phase.

Acetylcarnitine↗

Escalation of methamphetamine self-administration in rats: a dose-effect function.

RATIONALE: The transition from stable to escalated drug intake has been demonstrated in rats self-administrating cocaine and heroin using a single dose of drug. OBJECTIVES: To investigate the prolonged exposure to methamphetamine self-administration and the effect of various training doses of methamphetamine on the changes of methamphetamine intake over a 21-day period. METHODS: Two groups of rats were trained in 1-h daily sessions of methamphetamine self-administration [0.033 mg/infusion (inf); approximately 0.066 mg/kg/inf]. Methamphetamine access was increased to 6 h in one group [Long Access (LgA)] or maintained at 1 h in another [Short Access (ShA)]. The same procedure was repeated in rats exposed to different training doses of methamphetamine (0.05, 0.1, and 0.2 mg/kg/inf). RESULTS: In LgA rats, total and first hour intake of methamphetamine significantly increased compared to ShA rats at various methamphetamine doses. LgA animals, at all doses in the second study, escalated intake to 8-9 mg/kg per 6-h session, with the most rapid escalation occurring at 3-5 days at a methamphetamine dose of 0.1 mg/kg/inf. CONCLUSIONS: The escalation of drug intake observed with extended access is produced at multiple doses of methamphetamine. The rapidity of escalation depends on the dose. Ultimately, all doses in the dose-response study engendered self-administration of the same amount of total drug in a 6-h session in the extended-access group. Results suggest that the rapidity of escalation is dependent on dose and has an upper limit of intake over a period of 21 days.

Animals↗

Vulnerability to DNA damage in the aging rat substantia nigra: a study with the comet assay.

Oxidative DNA damage was measured in the substantia nigra (SN), cortex, hippocampus, striatum and hypothalamus of 3- and 24-month-old rats, using single-cell gel electrophoresis (SCGE, 'comet' assay) which allows the detection of DNA breaks and oxidized bases. A significant increase in basal DNA damage was selectively found in the SN of aged rats. FPG-sensitive oxidative DNA damage was also significantly increased in the SN of aged rats and, to a lesser extent, in the cortex and hypothalamus. These data show a higher vulnerability of SN to oxidative damage with aging and indicate that the detection of DNA damage within discrete brain nuclei can provide a reliable tool for investigating oxidative damage in neurodegenerative processes.

Aging↗

Blockade of nitric oxide synthesis reduces responding for cocaine self-administration during extinction and reinstatement.

Nitric oxide is a gaseous neurotransmitter that plays a significant role in various forms of synaptic plasticity and may play a role in the behavioral effects of psychostimulant drugs and in cocaine addiction. The course of drug addiction consists of different phases. Relapse into drug-seeking behavior following a period of abstinence is believed to represent one of the major factors leading to the perpetuation of the addictive cycle. In this respect, experimental extinction procedures provide a measure of the motivational properties of drugs as reflected by the persistence of drug-seeking behavior in the absence of the drug and by the reinstatement of responding by non-contingent drug administration. Pretreatment with the nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME, 50 mg/kg IP twice daily for 4 days) impaired responding for cocaine self-administration when the drug was available and the increase of drug-seeking behavior upon abrupt cessation of cocaine availability observed in control rats was significantly reduced after treatment with L-NAME. In addition, the priming effect of a non-contingent injection of cocaine on extinguished cocaine self-administration was also diminished by the same treatment. The acquisition of cocaine self-administration, in contrast, was not affected by treatment with L-NAME. These observations lend further support to the hypothesis of the involvement of nitric oxide in cocaine addiction and extend previous findings to components of the cocaine addictive cycle associated with relapse.

Animals↗

The neuroscience of drug addiction: Rome built in a day.

The Second Conference on the Neuroscience of Drug Addiction was a one-day meeting held in Rome, Italy at the Istituto Superiore di Sanità on 27 September 2002. Molecular, behavioral, pharmacological and clinical aspects of drug addiction were covered.

Animals↗