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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of a Synthetic Cannabinoid on the Reinforcing Efficacy of Ethanol in Rats

Bailey, Ericka M. 01 May 2007 (has links)
The co-abuse of alcohol and marijuana is widespread, although the mechanisms underlying this behavior are unclear. There is some evidence of a relationship between the neural processes that mediate the effects of ethanol and marijuana. For example, research has shown that exposure to marijuana increases responding for, and intake of, ethanol. The alcohol deprivation effect is an anima l model of alcoholism that suggests that the reinforcing efficacy of ethanol, as measured by intake, increases following a period of deprivation. Recent research indicates that rats chronically exposed to marijuana during periods of alcohol deprivation consume ethanol above and beyond deprivation alone. It is unclear, however, whether the marijuana exposure or the repeated deprivations increased motivation to consume ethanol. In the present experiment, rats were trained to self-administer ethanol on a progressive ratio schedule and subjected to two separate periods of deprivation during which either drug or saline was chronically administered for 7 days. Breakpoint (i.e., last ratio completed) was recorded as a measure of the reinforcing efficacy of ethanol. Following deprivations, breakpoint was initially lower than baseline, regardless of whether the drug or saline was administered. Breakpoint recovered to, but did not exceed, baseline levels following both deprivations, indicating a lack of increased reinforcing efficacy of ethanol after repeated deprivation or chronic exposure to marijuana. The lack of an expression of an alcohol deprivation effect following deprivation may have been due to the length and number of deprivations employed. Furthermore, lowered breakpoint recorded following chronic drug administration during deprivation may have been due to the dose administered or stress generated by chronic injections . Further investigation is necessary to separate and clarify the variables responsible for the present results.
2

An evaluation of commercially available solid phase extraction cartridges for the isolation of synthetic cannabinoid metabolites from urine

Forni, Amanda Marie 22 January 2016 (has links)
Synthetic cannabinoids were first created in a pharmaceutical setting where scientists were studying marijuana. Researchers were trying to develop medically beneficial marijuana analogs. The compounds, however, were found to give physiological effects that were more potent than marijuana. Presently, synthetic cannabinoids have become a psychoactive drug of abuse, sold in head shops and over the Internet. New compounds are constantly being synthesized, which makes analysis of the drugs difficult. Solid phase extraction (SPE) is a well-studied method used in toxicological analysis to extract drugs and their metabolites from biological fluids. This sample preparation method is necessary to isolate the desired components of a sample for analysis by gas chromatography and mass spectrometry (GC/MS). This study sought to compare four brands of commercially available SPE cartridges using a procedure from United Chemical Technologies (UCT) for the simultaneous extraction of the three synthetic cannabinoid metabolites, JWH-018 N-(4-hydroxypentyl), JWH-122 N-(5-hydroxypentyl), and JWH-250 N-(5-hydroxypentyl), from urine. The cartridges from UCT, Thermo Scientific, Agilent Technologies, and SiliCycle were evaluated to determine how they performed throughout the SPE procedure. A recovery efficiency study was conducted to measure the amount of extracted metabolites from the urine. The responses of the quantification ion of the metabolites from an extracted urine sample were compared to a neat sample and the percent recovery was calculated. A within-run precision study was also utilized to measure the reproducibility of the cartridges, which was determined by the coefficient of variation (CV) of the different brands. The outcome of this research led to a development of a GC/MS method for detection of the three metabolites, creation of calibration curves for quantification, use of SPE for the extraction of the metabolites from urine, and the quantification of the extracted compounds to determine the efficacy and consistency of four brands of SPE cartridges. Method optimization was able to minimize the interday variations seen in the results of aliquots of the same samples. Optimal parameters include initial validation of the GC/MS method, a clean liner for the analysis of synthetic cannabinoid metabolites, using a GC column with a high temperature limit, and derivatization of the extracts before injection into the GC. While this study shows it is possible to use GC/MS for the analysis of these metabolites, LC/MS does not have the same restrictions because a liner, temperature elution, and derivatization of the analytes are not utilized. It was determined from the results of these studies that SiliCycle had the most reproducible and efficient cartridges. SiliCycle cartridges had a consistent and fast flow rate with a percent recovery efficiency within ±20% of the actual value. The results from SiliCycle were followed by cartridges from UCT, Thermo Scientific, and Agilent brands, respectively.
3

Characterization of hepatocyte derived metabolites of various New Psychoactive Substances using LC-QTOF-MS.

Ingvarsson, Sarah January 2020 (has links)
New psychoactive substances are becoming increasingly common in many parts of the world, and some of them are marketed as “legal highs” and are produced to circumvent the drug legislation, and they come in many unregulated forms. The aim of this research was to characterize the metabolites of a new psychoactive substance and hence provide the fundamental data needed for further research of toxicity and future drug testing. The synthetic cannabinoid 4-fluoro-CUMYL-5-fluoro-PICA was incubated in cryopreserved hepatocytes for 1, 3 and 5 hour and then the formed metabolites was analyzed with an LC-QTOF-MS method, data analysis was performed by using the software MassHunter Qualitative Analysis. For 4-fluoro-CUMYL-5-fluoro-PICA a total of ten metabolites were identified, with three hydroxylations, two oxidative defluorinations to carboxylation, three oxidative defluorination and two fluoropentyl dealkylation. The metabolite with the highest intensity was oxidative defluorination.
4

Behavioral Assessment and HPLC/MS/MS Identification of the Synthetic Cannabinoid, CP47,497, in Mice

Samano, Kimberly L 26 March 2014 (has links)
CP47,497 and other synthetic cannabinoid compounds were incipiently synthesized as research tools to investigate the mechanisms by which marijuana affects the brain and to aid in the development of therapeutic agents. Recently, these cannabinoid compounds have resurfaced in the designer drug market, marketed as “herbal incense products” (HIPs). Their popular use has resulted in an alarming rate of reported adverse effects and toxicities. Current legislation classified CP47,497 and several other synthetic cannabinoids compounds as Schedule I agents, but abuse of these compounds persists with serious consequences to public health and safety. In vivo studies examining the behavioral consequences of abused synthetic cannabinoids are limited. As a result, the goals of this research were to elucidate the acute and chronic pharmacological effects of CP47,497 and to develop a bioanalytical method for CP47,497 drug detection in mice. Cannabimimetic effects were evaluated in well-established in vivo models, the tetrad paradigm and drug discrimination assay. The tetrad test is comprised of four outcome measures sensitive to the primary psychoactive cannabinoid present in marijuana, delta-9-tetrahydrocannabinol (THC): catalepsy (bar test), antinociception (tail withdrawal latency), hypothermia, and decreases in spontaneous locomotor activity. While many pharmacological agents can produce one or a subset of these tetrad effects, drugs that activate CB1 receptors produce characteristic effects in all four parameters. An HPLC/MS/MS method was developed and confirmed the presence of CP47,497 in brain. We investigated whether CB1 receptors mediate the pharmacological effects of CP47,497. Cumulative dose-response experiments determined CP47,497 is more potent than THC in vivo in using multiple behavioral assays. Complementary pharmacological (CB1 receptor antagonist, rimonabant) and genetic (CB1 (-/-) mice) approaches were used to investigate whether CB1 receptors mediate the effects of CP47,497. Rimonabant (3 mg/kg or 10 mg/kg, depending on independent measure) blocked all cannabinoid-like pharmacological effects of CP47,497. Supporting these findings, CB1(-/-) mice were resistant to cannabimimetic effects of CP47,497. CP47,497 fully substituted for THC in the drug discrimination assay, with a potency of more than 5 times that of THC. Collectively, these results indicate that CP47,497 is markedly more potent (i.e. 5-8 fold) than THC, and its repeated administration produces tolerance to the cataleptic, antinociceptive, hypothermic and hypolocomotor effects in mice, with significant presentation of somatic withdrawal signs (paw flutter and head shakes) upon drug cessation. These findings are consistent with the high incidence of adverse events in humans abusing synthetic cannabinoids.

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