The new psychoactive substances 5-(2-aminopropyl)indole (5-IT) and 6-(2-aminopropyl)indole (6-IT) interact with monoamine transporters in brain tissue

In recent years, use of psychoactive synthetic stimulants has grown rapidly. 5-(2-Aminopropyl)indole (5-IT) is a synthetic drug associated with a number of fatalities, that appears to be one of the newest 3,4-methylenedioxymethamphetamine (MDMA) replacements. Here, the monoamine-releasing properties of 5-IT, its structural isomer 6-(2-aminopropyl)indole (6-IT), and MDMA were compared using in vitro release assays at transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT) in rat brain synaptosomes. In vivo pharmacology was assessed by locomotor activity and a functional observational battery (FOB) in mice. 5-IT and 6-IT were potent substrates at DAT, NET, and SERT. In contrast with the non-selective releasing properties of MDMA, 5-IT displayed greater potency for release at DAT over SERT, while 6-IT displayed greater potency for release at SERT over DAT. 5-IT produced locomotor stimulation and typical stimulant effects in the FOB similar to those produced by MDMA. Conversely, 6-IT increased behaviors associated with 5-HT toxicity. 5-IT likely has high abuse potential, which may be somewhat diminished by its slow onset of in vivo effects, whereas 6-IT may have low abuse liability, but enhanced risk for adverse effects. Results indicate that subtle differences in the chemical structure of transporter ligands can have profound effects on biological activity. The potent monoamine-releasing actions of 5-IT, coupled with its known inhibition of MAO A, could underlie its dangerous effects when administered alone, and in combination with other monoaminergic drugs or medications. Consequently, 5-IT and related compounds may pose substantial risk for abuse and serious adverse effects in human users

Pharmacology of MDMA- and Amphetamine-Like New Psychoactive Substances

New psychoactive substances (NPS) with amphetamine-, aminoindan-, and benzofuran basic chemical structures have recently emerged for recreational drug use. Detailed information about their psychotropic effects and health risks is often limited. At the same time, it emerged that the pharmacological profiles of these NPS resemble those of amphetamine or 3,4-methylenedioxymethamphetamine (MDMA). Amphetamine-like NPS induce psychostimulation and euphoria mediated predominantly by norepinephrine (NE) and dopamine (DA) transporter (NET and DAT) inhibition and transporter-mediated release of NE and DA, thus showing a more catecholamine-selective profile. MDMA-like NPS frequently induce well-being, empathy, and prosocial effects and have only moderate psychostimulant properties. These MDMA-like substances primarily act by inhibiting the serotonin (5-HT) transporter (SERT) and NET, also inducing 5-HT and NE release. Monoamine receptor interactions vary considerably among amphetamine- and MDMA-like NPS. Clinically, amphetamine- and MDMA-like NPS can induce sympathomimetic toxicity. The aim of this chapter is to review the state of knowledge regarding these substances with a focus on the description of the in vitro pharmacology of selected amphetamine- and MDMA-like NPS. In addition, it is aimed to provide links between pharmacological profiles and in vivo effects and toxicity, which leads to the conclusion that abuse liability for amphetamine-like NPS may be higher than for MDMA-like NPS, but that the risk for developing the life-threatening serotonin syndrome may be increased for MDMA-like NPS

Hypothalamic neuronal circuits involved in the regulation of food intake and body weight : Histochemical studies in lean rats and obese mutant mice

Obesity is a major health problem because of its dramatic increase in prevalence and its association with type 2 diabetes, coronary heart diseases, hypertension and stroke. It is well known that signals generated in response to feeding behavior are integrated in the brain. In particular, neuronal circuits located in the hypothalamus exert powerful effects on food intake and body weight. Specific neuronal populations located in the ventromedial and lateral hypothalamus express mediators, which stimulate or inhibit food intake. Such neurons are targets for peripheral hormones that signal to the brain about the energy status of the organism. The aim of this thesis has been to study proteins and peptides that participate in the hypothalamic control of body weight. in order to better understand the neuronal circuits regulating feeding behavior, the cellular localization of transmitters, receptors and signal transduction molecules have been studied in normal rat hypothalamus. Special interest has been focused on possible alterations in neurochemical markers in animal models with obesity, thereby providing knowledge regarding the mechanisms of pathogenesis underlying the development of obesity. For this purpose obese ob/ob and tub/tub mice were used. The ob/ob mouse, which has a mutation in the ob gene, lacks functional leptin and exhibits a phenotype including severe obesity, insulin resistance and infertility. Leptin is an adipocyte tissue-derived hormone, which inhibits food intake and increases energy expenditure via an action on leptin receptors located in the hypothalamus. A mutation in the mouse tub gene causes maturityonset obesity, insulin resistance, retinal degeneration, and neurosensory hearing loss. Since the tub/tub mouse develops maturity-onset obesity, this obese mouse model is particularly interesting and relevant to human obesity. We have therefore investigated whether the neuronal circuits that participate in hypothalamic control of body weight are altered in the tub/tub mouse. Using immunohistochemistry, gamma-ammobutyric acid (GABA), an orexigenic neurotransmitter, was demonstrated to be present in leptin target neurons of the arcuate nucleus. The GABAergic leptin-target neurons belong to the orexigenic neuropeptide Y (NPY)/agouti-related protein (AGRP)-containing, but not the anotexigenic proopiomelanocortin (POMC)/cocaine- and amphetamme-regulated transcript (CART)-containing cell population of the arcuate nucleus. In order to find out whether leptin acts via GABA to regulate food intake, we compared mRNA levels for GABAergic markers in obese leptin-deficient o/lob mice with lean controls. There were no significant differences in the mRNA levels for glutamic acid decarboxylase (GAD) isoforms GAD65 and GAD67 or the vesicular GABA transporter (VGAT), which suggests that chronic leptin deficiency does not have a major regulatory role on transcription of these genes. However, a role for leptin on GABAergic neurotransmission other than transcriptional regulation cannot be excluded GABA binds to two types of receptors, ionotropic GABAA and metabotropic GABAB receptors. Immunoreactivities for both GABAA and GABAB receptors were demonstrated in several hypothalamic regions associated with regulation of body weight control and colocalized with peptides that are known mediators of ingestive behavior. Orexins, also called hypocretins, are produced exclusively in the lateral hypothalamic area and have important roles in regulation of feeding behavior and arousal. The orexins act via the two orexin receptors, OX-R1 and OX-R2. Immunohistochemical analysis was used to chemically characterize OX-R1 immunoreactive neurons in the hypothalamus. OX-R1-containing neurons were shown to contain several mediators that regulate feeding and drinking behavior. Behavioral and histochemical analysis revealed several abnormalities in obese tub/tub mice. It was concluded that tub/tub are obese as a results of increased eating behavior (hyperphagia). Immunohistochemistry showed presence of abnormally large nerve terminals surrounding blood vessels containing acetylcholine and GABA in the ventromedial part of the arcuate nucleus of obese tub/tub mice, but not in tub/+ mice. In situ hybridization and immunohistochemistry was used to demonstrate that tub/tub mice have a down-regulated expression of AGRP mRNA in the arcuate nucleus combined with lower fluorescence intensity and numbers of AGRP- and NPY-immunoreactive fibers and terminals in the hypothalamus. The results obtained in tub/tub mice may facilitate the understanding of the mechanism underlying the obese phenotype in mice with a mutation in the tub gene

Drug trends and harm related to new psychoactive substances (NPS) in Sweden from 2010 to 2016: Experiences from the STRIDA project.

BackgroundIn the past decade, hundreds of new psychoactive substances (NPS) have been introduced as unclassified alternatives to the illicit drugs. The NPS represent a growing health concern by causing adverse effects and deaths but are usually undetectable by conventional drug tests. This report summarizes results and experiences from analytically confirmed drug-related acute intoxications in emergency departments (ED) and intensive care units (ICU) enrolled in the Swedish STRIDA project on NPS in 2010-2016.Methods and findingsED/ICU intoxications suspected to involve NPS were enrolled in the project, after initial contact with the Poisons Information Centre (PIC). Serum/plasma and urine samples, and sometimes drug products, were subjected to a comprehensive toxicological investigation, and the PIC retrieved information on associated clinical symptoms and treatment. Between January 2010-February 2016, 2626 cases were enrolled. The patients were aged 8-71 (mean 27, median 24) years and 74% were men. Most biological samples (81%) tested positive for one, or more (70%), psychoactive drugs, including 159 NPS, other novel or uncommon substances, classical recreational and illicit drugs, and prescription medications. When first detected, most NPS or other novel substances (75%) were not banned in Sweden, but they usually disappeared upon classification, which however often took a year or longer. Some NPS were found to be especially harmful and even fatal.ConclusionsThe STRIDA project provided a good overview of the current drug situation in Sweden and demonstrated a widespread use and rapid turnover of many different psychoactive substances. The accomplishment of the project can be attributed to several key factors (close collaboration between the PIC and laboratory to identify suspected poisonings, free analysis, continuous updating of analytical methods, evaluation of adverse effects, and sharing information) that are useful for future activities addressing the NPS problem. The results also illustrated how drug regulations can drive the NPS market

3R-Refinement principles : elevating rodent well-being and research quality

This review article delves into the details of the 3R-Refinement principles as a vital framework for ethically sound rodent research laboratory. It highlights the core objective of the refinement protocol, namely, to enhance the well-being of laboratory animals while simultaneously improving the scientific validity of research outcomes. Through an exploration of key components of the refinement principles, the article outlines how these ethics should be implemented at various stages of animal experiments. It emphasizes the significance of enriched housing environments that reduce stress and encourage natural behaviors, non-restraint methods in handling and training, refined dosing and sampling techniques that prioritize animal comfort, the critical role of optimal pain management and the importance of regular animal welfare assessment in maintaining the rodents well-being. Additionally, the advantages of collaboration with animal care and ethics committees are also mentioned. The other half of the article explains the extensive benefits of the 3R-Refinement protocol such as heightened animal welfare, enhanced research quality, reduced variability, and positive feedback from researchers and animal care staff. Furthermore, it addresses avenues for promoting the adoption of the protocol, such as disseminating best practices, conducting training programs, and engaging with regulatory bodies. Overall, this article highlights the significance of 3R-Refinement protocol in aligning scientific advancement with ethical considerations along with shaping a more compassionate and responsible future for animal research. Correspondence Address: M. Bäckberg; RISE Research Institutes of Sweden, Sweden. </p

3R-Refinement principles : elevating rodent well-being and research quality

This review article delves into the details of the 3R-Refinement principles as a vital framework for ethically sound rodent research laboratory. It highlights the core objective of the refinement protocol, namely, to enhance the well-being of laboratory animals while simultaneously improving the scientific validity of research outcomes. Through an exploration of key components of the refinement principles, the article outlines how these ethics should be implemented at various stages of animal experiments. It emphasizes the significance of enriched housing environments that reduce stress and encourage natural behaviors, non-restraint methods in handling and training, refined dosing and sampling techniques that prioritize animal comfort, the critical role of optimal pain management and the importance of regular animal welfare assessment in maintaining the rodents well-being. Additionally, the advantages of collaboration with animal care and ethics committees are also mentioned. The other half of the article explains the extensive benefits of the 3R-Refinement protocol such as heightened animal welfare, enhanced research quality, reduced variability, and positive feedback from researchers and animal care staff. Furthermore, it addresses avenues for promoting the adoption of the protocol, such as disseminating best practices, conducting training programs, and engaging with regulatory bodies. Overall, this article highlights the significance of 3R-Refinement protocol in aligning scientific advancement with ethical considerations along with shaping a more compassionate and responsible future for animal research. Correspondence Address: M. Bäckberg; RISE Research Institutes of Sweden, Sweden. </p