RESUMO
As the world population ages, there will be an increasing need for effective therapies for aging-associated neurodegenerative disorders, which remain untreatable. Dementia due to Alzheimer's disease (AD) is one of the leading neurological diseases in the aging population. Current therapeutic approaches to treat this disorder are solely symptomatic, making the need for new molecular entities acting on the causes of the disease extremely urgent. One of the potential solutions is to use compounds that are already in the market. The structures have known pharmacokinetics, pharmacodynamics, toxicity profiles, and patient data available in several countries. Several drugs have been used successfully to treat diseases different from their original purposes, such as autoimmunity and peripheral inflammation. Herein, we divulge the repurposing of drugs in the area of neurodegenerative diseases, focusing on the therapeutic potential of antineoplastics to treat dementia due to AD and dementia. We briefly touch upon the shared pathological mechanism between AD and cancer and drug repurposing strategies, with a focus on artificial intelligence. Next, we bring out the current status of research on the development of drugs, provide supporting evidence from retrospective, clinical, and preclinical studies on antineoplastic use, and bring in new areas, such as repurposing drugs for the prion-like spreading of pathologies in treating AD.
Assuntos
Doença de Alzheimer , Antineoplásicos , Demência , Reposicionamento de Medicamentos , Humanos , Doença de Alzheimer/tratamento farmacológico , Animais , Demência/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Estudos Observacionais como Assunto , Avaliação Pré-Clínica de MedicamentosRESUMO
Nucleoside-based drugs, recognized as purine or pyrimidine analogs, have been potent therapeutic agents since their introduction in 1950, deployed widely in the treatment of diverse diseases such as cancers, myelodysplastic syndromes, multiple sclerosis, and viral infections. These antimetabolites establish complex interactions with cellular molecular constituents, primarily via activation of phosphorylation cascades leading to consequential interactions with nucleic acids. However, the therapeutic efficacy of these agents is frequently compromised by the development of drug resistance, a continually emerging challenge in their clinical application. This comprehensive review explores the mechanisms of resistance to nucleoside-based drugs, encompassing a wide spectrum of phenomena from alterations in membrane transporters and activating kinases to changes in drug elimination strategies and DNA damage repair mechanisms. The critical analysis in this review underlines complex interactions of drug and cell and also guides towards novel therapeutic strategies to counteract resistance. The development of targeted therapies, novel nucleoside analogs, and synergistic drug combinations are promising approaches to restore tumor sensitivity and improve patient outcomes.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Nucleosídeos/farmacologia , Nucleosídeos/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Resistência a Medicamentos , Proteínas de Membrana Transportadoras , Antimetabólitos/farmacologiaRESUMO
Microtubule dynamic is exceptionally sensitive to modulation by small-molecule ligands. Our previous work presented the preparation of microtubule-targeting estradiol dimer (ED) with anticancer activity. In the present study, we explore the effect of selected linkers on the biological activity of the dimer. The linkers were designed as five-atom chains with carbon, nitrogen or oxygen in their centre. In addition, the central nitrogen was modified by a benzyl group with hydroxy or methoxy substituents and one derivative possessed an extended linker length. Thirteen new dimers were subjected to cytotoxicity assay and cell cycle profiling. Dimers containing linker with benzyl moiety substituted with one or more methoxy groups and longer branched ones were found inactive, whereas other structures had comparable efficacy as the original ED (e.g. D1 with IC50 = 1.53 µM). Cell cycle analysis and immunofluorescence proved the interference of dimers with microtubule assembly and mitosis. The proposed in silico model and calculated binding free energy by the MM-PBSA method were closely correlated with in vitro tubulin assembly assay.
Assuntos
Antineoplásicos , Etinilestradiol , Triazóis , Moduladores de Tubulina , Tubulina (Proteína) , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Etinilestradiol/química , Etinilestradiol/farmacologia , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Microtúbulos , Triazóis/química , Triazóis/farmacologia , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologiaRESUMO
MAP/microtubule affinity-regulating kinases (MARKs) were recently identified as potential drug targets for Alzheimer's disease (AD) due to their role in pathological hyperphosphorylation of tau protein. Hyperphosphorylated tau has decreased affinity for microtubule binding, impairing their stability and associated functions. Destabilization of microtubules in neuronal cells leads to neurodegeneration, and microtubule-unbound tau forms neurofibrillary tangles, one of the primary hallmarks of AD. Many phosphorylation sites of tau protein have been identified, but phosphorylation at Ser262, which occurs in early stages of AD, plays a vital role in the pathological hyperphosphorylation of tau. It has been found that Ser262 is phosphorylated by MARK4, which is currently an intensively studied target for treating Alzheimer's disease and other neurodegenerative diseases. Our present study aimed to develop a high throughput compatible assay to directly detect MARK enzymatic activity using echoacoustic transfer and MALDI-TOF mass spectrometer. We optimized the assay for all four isoforms of MARK and validated its use for identifying potential inhibitors by the screening of 1280 compounds from the LOPAC®1280 International (Library Of Pharmacologically Active Compounds). Six MARK4 inhibitors with IC50 < 1 µM were identified. To demonstrate their therapeutic potential, active compounds were further tested for MARK4 selectivity and ability to cross the blood-brain barrier. Lastly, the molecular docking with the most active inhibitors to predict their interaction with MARK4 was performed.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Barreira Hematoencefálica/metabolismo , Concentração Inibidora 50 , Microtúbulos/metabolismo , Simulação de Acoplamento Molecular , Fosforilação/fisiologia , Proteínas tau/metabolismoRESUMO
Synthetic cannabinoids have been prohibited due to abuse liability and toxicity. Four such synthetic cannabinoids, AM-2201 ([1-(5-fluoropentyl)indol-3-yl]-naphthalen-1-ylmethanone), CP-47,497 (2-[(1R,3S)-3-hydroxycyclohexyl]-5-(2-methyloctan-2-yl)phenol), JWH-122 [(4-methylnaphthalen-1-yl)-(1-pentylindol-3-yl)methanone], and JWH-250 [2-(2-methoxyphenyl)-1-(1-pentylindol-3-yl)ethanone], were tested for their capacity to produce CB1 receptor-mediated discriminative stimulus effects in two groups of rhesus monkeys. One group (n = 4) discriminated Δ9-tetrahydrocannabinol (∆9-THC; 0.1 mg/kg i.v.), and a second group (n = 4) discriminated the cannabinoid antagonist rimonabant (1 mg/kg i.v.) while receiving 1 mg/kg/12 hours of ∆9-THC. AM-2201, JWH-122, CP-47,497, JWH-250, and ∆9-THC increased ∆9-THC lever responding. Duration of action was 1-2 hours for AM-2201, JWH-122, and JWH-250 and 4-5 hours for CP-47,497 and ∆9-THC. Rimonabant (1 mg/kg) surmountably antagonized the discriminative stimulus effects of all cannabinoid agonists; the magnitude of rightward shift was 10.6-fold for AM-2201, 10.7-fold for JWH-122, 11.0-fold for CP-47,497, and 15.7-fold for JWH-250. The respective pKB values were not significantly different: 6.61, 6.65, 6.66, and 6.83. In ∆9-THC-treated monkeys discriminating rimonabant, AM-2201 (0.1 and 0.32 mg/kg), JWH-122 (0.32 and 1 mg/kg), JWH-250 (1 and 3.2 mg/kg), and CP-47,497 (0.32, 1, and 3.2 mg/kg) produced not only rate-decreasing effects that were reversed by rimonabant, but also dose-dependent, rightward shifts in the rimonabant discrimination dose-effect function. These results show striking similarity in the CB1 receptor mechanism mediating the subjective effects of AM-2201, JWH-122, JWH-250, and CP-47,497. For products containing AM-2201 and JWH-122, a short duration of action could lead to more frequent use; moreover, inattention to differences in potency among synthetic cannabinoids could underlie unexpected toxicity. Rapid reversal of effects by intravenous rimonabant has potential value in emergency situations.
Assuntos
Antagonistas de Receptores de Canabinoides/metabolismo , Canabinoides/metabolismo , Cicloexanóis/metabolismo , Indóis/metabolismo , Naftalenos/metabolismo , Piperidinas/metabolismo , Pirazóis/metabolismo , Animais , Antagonistas de Receptores de Canabinoides/farmacologia , Canabinoides/farmacologia , Cicloexanóis/farmacologia , Aprendizagem por Discriminação/efeitos dos fármacos , Aprendizagem por Discriminação/fisiologia , Relação Dose-Resposta a Droga , Feminino , Indóis/farmacologia , Macaca mulatta , Masculino , Naftalenos/farmacologia , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/agonistas , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/metabolismo , RimonabantoRESUMO
Investigation of a series of tetra(3,4-pyrido)porphyrazines (TPyPzs) substituted with hydrophilic substituents revealed important structure-activity relationships for their use in photodynamic therapy (PDT). Among them, a cationic TPyPz derivative with total of 12 cationic charges above, below and in the plane of the core featured a unique spatial arrangement that caught the hydrophobic core in a cage, thereby protecting it fully from aggregation in water. This derivative exhibited exceptionally effective photodynamic activity on a number of tumor cell lines (HeLa, SK-MEL-28, A549, MCF-7) with effective concentrations (EC50) typically below 5 nM, at least an order of magnitude better than the EC50 values obtained for the clinically approved photosensitizers verteporfin, temoporfin, protoporphyrin IX, and trisulfonated hydroxyaluminum phthalocyanine. Its very low dark toxicity (TC50 > 400 µM) and high ability to induce photodamage to endothelial cells (EA.hy926) without preincubation suggest the high potential of this cationic TPyPz derivative in vascular-targeted PDT.
Assuntos
Metaloporfirinas/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Piridinas/farmacologia , Células 3T3 , Animais , Cátions/síntese química , Cátions/química , Cátions/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Endoteliais/efeitos dos fármacos , Células HeLa , Humanos , Células MCF-7 , Metaloporfirinas/síntese química , Metaloporfirinas/química , Camundongos , Estrutura Molecular , Fotoquimioterapia , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Inhibition of fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL), the primary hydrolytic enzymes for the respective endocannabinoids N-arachidonoylethanolamine (AEA) and 2-arachidonylglycerol (2-AG), produces antinociception but with minimal cannabimimetic side effects. Although selective inhibitors of either enzyme often show partial efficacy in various nociceptive models, their combined blockade elicits augmented antinociceptive effects, but side effects emerge. Moreover, complete and prolonged MAGL blockade leads to cannabinoid receptor type 1 (CB1) receptor functional tolerance, which represents another challenge in this potential therapeutic strategy. Therefore, the present study tested whether full FAAH inhibition combined with partial MAGL inhibition would produce sustained antinociceptive effects with minimal cannabimimetic side effects. Accordingly, we tested a high dose of the FAAH inhibitor PF-3845 (N-â3-âpyridinyl-â4-â[[3-â[[5-â(trifluoromethyl)-â2-âpyridinyl]oxy]phenyl]methyl]-â1-âpiperidinecarboxamide; 10 mg/kg) given in combination with a low dose of the MAGL inhibitor JZL184 [4-nitrophenyl 4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate] (4 mg/kg) in mouse models of inflammatory and neuropathic pain. This combination of inhibitors elicited profound increases in brain AEA levels (>10-fold) but only 2- to 3-fold increases in brain 2-AG levels. This combination produced significantly greater antinociceptive effects than single enzyme inhibition and did not elicit common cannabimimetic effects (e.g., catalepsy, hypomotility, hypothermia, and substitution for Δ(9)-tetrahydrocannabinol in the drug-discrimination assay), although these side effects emerged with high-dose JZL184 (i.e., 100 mg/kg). Finally, repeated administration of this combination did not lead to tolerance to its antiallodynic actions in the carrageenan assay or CB1 receptor functional tolerance. Thus, full FAAH inhibition combined with partial MAGL inhibition reduces neuropathic and inflammatory pain states with minimal cannabimimetic effects.
Assuntos
Amidoidrolases/antagonistas & inibidores , Analgésicos/administração & dosagem , Agonistas de Receptores de Canabinoides/administração & dosagem , Antagonistas de Receptores de Canabinoides/administração & dosagem , Monoacilglicerol Lipases/antagonistas & inibidores , Amidoidrolases/metabolismo , Animais , Benzodioxóis/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Quimioterapia Combinada , Hiperalgesia/tratamento farmacológico , Hiperalgesia/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monoacilglicerol Lipases/metabolismo , Piperidinas/administração & dosagem , Piridinas/administração & dosagem , Receptor CB1 de Canabinoide/agonistas , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/metabolismo , Fatores de Tempo , Resultado do TratamentoRESUMO
Monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) inhibitors exert preclinical effects indicative of therapeutic potential (i.e., analgesia). However, the extent to which MAGL and FAAH inhibitors produce unwanted effects remains unclear. Here, FAAH and MAGL inhibition was examined separately and together in a Δ(9)-tetrahydrocannabinol (Δ(9)-THC; 5.6 mg/kg i.p.) discrimination assay predictive of subjective effects associated with cannabis use, and the relative contribution of N-arachidonoyl ethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) in the prefrontal cortex, hippocampus, and caudate putamen to those effects was examined. Δ(9)-THC dose-dependently increased Δ(9)-THC appropriate responses (ED50 value = 2.8 mg/kg), whereas the FAAH inhibitors PF-3845 [N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide] and URB597 [(3'-â(aminocarbonyl)[1,â1'-âbiphenyl]-â3-âyl)-âcyclohexylcarbamate] or a MAGL inhibitor JZL184 [4-ânitrophenyl-â4-â(dibenzo[d][1,â3]dioxol-â5-âyl(hydroxy)methyl)piperidine-â1-âcarboxylate] alone did not substitute for the Δ(9)-THC discriminative stimulus. The nonselective FAAH/MAGL inhibitors SA-57 [4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester] and JZL195 [4-ânitrophenyl 4-â(3-âphenoxybenzyl)piperazine-â1-âcarboxylate] fully substituted for Δ(9)-THC with ED50 values equal to 2.4 and 17 mg/kg, respectively. Full substitution for Δ(9)-THC was also produced by a combination of JZL184 and PF-3845, but not by a combination of JZL184 and URB597 (i.e., 52% maximum). Cannabinoid receptor type 1 antagonist rimonabant attenuated the discriminative stimulus effects of Δ(9)-THC, SA-57, JZL195, and the combined effects of JZL184 and PF-3845. Full substitution for the Δ(9)-THC discriminative stimulus occurred only when both 2-AG and AEA were significantly elevated, and the patterns of increased endocannabinoid content were similar among brain regions. Overall, these results suggest that increasing both endogenous 2-AG and AEA produces qualitatively unique effects (i.e., the subjective effects of cannabis) that are not obtained from increasing either 2-AG or AEA separately.
Assuntos
Amidoidrolases/antagonistas & inibidores , Dronabinol/farmacologia , Inibidores Enzimáticos/farmacologia , Monoacilglicerol Lipases/antagonistas & inibidores , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Endocanabinoides/metabolismo , Masculino , CamundongosRESUMO
BACKGROUND: Recent changes in the legality of cannabis have prompted evaluation of whether blood levels of Δ(9)-tetrahydrocannabinol (THC) or its metabolites could be used to substantiate impairment, particularly related to behavioral tasks such as driving. However, because marked tolerance develops to behavioral effects of THC, the applicability of a particular threshold of blood THC as an index of impairment in people with different patterns of use remains unclear. Studies relevant to this issue are difficult to accomplish in humans, as prior drug exposure is difficult to control. METHODS: Here, effects of THC to decrease rectal temperature and operant response rate compared to levels of THC and its metabolites were studied in blood in two groups of monkeys: one received intermittent treatment with THC (0.1 mg/kg i.v. every 3-4 days) and another received chronic THC (1 mg/kg/12 h s.c.) for several years. RESULTS: In monkeys with intermittent THC exposure, a single dose of THC (3.2 mg/kg s.c.) decreased rectal temperature and response rate. The same dose did not affect response rate or rectal temperature in chronically exposed monkeys, indicative of greater tolerance. In both groups, blood levels of THC peaked 20-60 min post-injection and had a similar half-life of elimination, indicating no tolerance to the pharmacokinetics of THC. Notably, in both groups, the behavioral effects of THC were not apparent when blood levels were maximal (20-min post-administration). CONCLUSION: These data indicate that thresholds for blood levels of THC do not provide a consistent index of behavioral impairment across individuals with different patterns of THC exposure.
Assuntos
Dronabinol/sangue , Animais , Temperatura Corporal/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Dronabinol/administração & dosagem , Dronabinol/farmacocinética , Dronabinol/farmacologia , Esquema de Medicação , Feminino , Meia-Vida , Macaca mulatta/sangue , Masculino , Desempenho Psicomotor/efeitos dos fármacosRESUMO
Synthetic cannabinoid abuse and case reports of adverse effects have raised concerns about the pharmacologic mechanisms underlying in vivo effects. Here, a synthetic cannabinoid identified in abused products (HU-210) was compared to the effects of Δ(9)-THC and two other synthetic cannabinoid agonists used extensively in pre-clinical studies (CP 55,940 and WIN 55,212-2). One group of monkeys discriminated ∆(9)-THC (0.1mg/kg i.v.); a separate group received chronic ∆(9)-THC (1mg/kg/12h s.c.) and discriminated rimonabant (1mg/kg i.v.). CP 55,940, HU-210, ∆(9)-THC, and WIN 55,212-2 produced ∆(9)-THC lever responding. HU-210 had a long duration (i.e., 1-2 days), whereas that of the other cannabinoids was 5h or less. Rimonabant (1mg/kg) produced surmountable antagonism; single dose-apparent affinity estimates determined in the presence of ∆(9)-THC, CP 55,940, and WIN 55,212-2 did not differ from each other. In contrast, rimonabant (1mg/kg) produced a smaller rightward shift in the HU-210 dose-effect function. In ∆(9)-THC treated monkeys, the relative potency of CP 55,940, ∆(9)-THC, and WIN 55,212-2 to attenuate the discriminative stimulus effects of rimonabant was the same as that evidenced in the ∆(9)-THC discrimination, whereas HU-210 was unexpectedly more potent in attenuating the effects of rimonabant. In conclusion, the same receptor subtype mediates the discriminative stimulus effects of ∆(9)-THC, CP 55,940 and WIN 55,212-2. The limited effectiveness of rimonabant to either prevent or reverse the effects of HU-210 appears to be due to very slow dissociation or pseudo-irreversible binding of HU-210 at cannabinoid receptors.
Assuntos
Comportamento Animal/efeitos dos fármacos , Agonistas de Receptores de Canabinoides/farmacologia , Discriminação Psicológica/efeitos dos fármacos , Dronabinol/análogos & derivados , Receptores de Canabinoides/efeitos dos fármacos , Animais , Benzoxazinas/farmacologia , Agonistas de Receptores de Canabinoides/metabolismo , Antagonistas de Receptores de Canabinoides , Cicloexanóis/farmacologia , Relação Dose-Resposta a Droga , Dronabinol/metabolismo , Dronabinol/farmacologia , Feminino , Macaca mulatta , Masculino , Morfolinas/farmacologia , Naftalenos/farmacologia , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptores de Canabinoides/metabolismo , Rimonabanto , Fatores de TempoRESUMO
The aim of the present study was to compare the response to sub-chronic application of methamphetamine (MA) in adulthood in male and female rats prenatally exposed to the same drug. The spontaneous locomotor activity and exploratory behavior of adult male and female rats prenatally exposed to 5 mg/kg MA or saline (SAL) were tested in a Laboras apparatus (Metris B.V., Netherlands) for five consecutive days, 1 hr daily. MA 1 mg/kg or SAL were used as a challenge prior to testing. Our results showed that rats prenatally exposed to MA were more sensitive to sub-chronic administration of MA in adulthood than prenatally SAL-exposed rats. However, this sensitizing effect of prenatal MA exposure was manifested differently in males and females. In contrast, prenatal MA exposure decreased baseline locomotion in females. This study indicates that gender plays an important role in the sensitivity to MA during prenatal development and in adulthood.
Assuntos
Comportamento Animal/efeitos dos fármacos , Metanfetamina/farmacologia , Efeitos Tardios da Exposição Pré-Natal , Análise de Variância , Animais , Feminino , Masculino , Gravidez , Ratos , Ratos Wistar , Fatores SexuaisRESUMO
Synthetic cannabinoids (CBs) [naphthalen-1-yl-(1-pentylindol-3-yl) methanone (JWH-018) and naphthalen-1-yl-(1-butylindol-3-yl) methanone (JWH-073)] are marketed, sold, and used as alternatives to cannabis. Synthetic CBs appear to have effects similar to those of Δ9-tetrahydrocannabinol (Δ9-THC), the drug primarily responsible for the behavioral effects of cannabis. However, synthetic CB products produce atypical effects (e.g., hypertension, seizures, and panic attacks). One potential explanation for atypical effects is CB1 receptor agonist efficacy, which is reportedly higher for JWH-018 and JWH-073 compared with Δ9-THC. The goal of this study was to test a prediction from receptor theory that tolerance/cross-tolerance (i.e., resulting from daily Δ9-THC treatment) is greater for a low-efficacy agonist compared with a high-efficacy agonist. Rhesus monkeys discriminated 0.1 mg/kg Δ9-THC i.v. from vehicle, and sensitivity to CB(1) agonists was determined before and after 3 and 14 days of Δ9-THC treatment (1 mg/kg per day s.c.). (1R,3R,4R)-3-[2-Hydroxy-4-(1,1-dimethylheptyl) phenyl]-4-(3-hydroxypropyl)cyclohexan-1-ol (CP-55,940), a prototype high-efficacy CB1 receptor agonist, JWH-018, and JWH-073 substituted for the discriminative stimulus effects of Δ9-THC. Three days of Δ9-THC treatment produced less tolerance/cross-tolerance than 14 days of Δ9-THC treatment. Three days of Δ9-THC did not result in cross-tolerance to CP-55,940, JWH-073, and JWH-018; in contrast, as reported previously, 3 days of Δ9-THC treatment decreased sensitivity to Δ9-THC 3-fold. Fourteen days of Δ9-THC decreased sensitivity to Δ9-THC, CP-55,940, JWH-018, and JWH-073 9.2-fold, 3.6-fold, 4.3-fold, and 5.6-fold, respectively. The greater loss of sensitivity to Δ9-THC relative to CP-55,940 and JWH-018 suggests that differences in CB1 receptor agonist efficacy are important in vivo and might underlie differences in the dependence liability and adverse effects of synthetic CBs versus cannabis.
Assuntos
Canabinoides/agonistas , Dronabinol/farmacologia , Receptor CB1 de Canabinoide/agonistas , Animais , Cannabis/efeitos adversos , Cicloexanóis/farmacologia , Tolerância a Medicamentos , Feminino , Indóis/farmacologia , Macaca mulatta , Masculino , Naftalenos/farmacologiaRESUMO
Products containing naphthalen-1-yl-(1-pentylindol-3-yl) methanone (JWH-018) and naphthalen-1-yl-(1-butylindol-3-yl) methanone (JWH-073) are emerging drugs of abuse. Here, the behavioral effects of JWH-018 and JWH-073 were examined in one behavioral assay selective for cannabinoid agonism, rhesus monkeys (n = 4) discriminating Δ9-tetrahydrocannabinol (Δ9-THC; 0.1 mg/kg i.v.), and another assay sensitive to cannabinoid withdrawal, i.e., monkeys (n = 3) discriminating the cannabinoid antagonist rimonabant (1 mg/kg i.v.) during chronic Δ9-THC (1 mg/kg s.c. 12 h) treatment. Δ9-THC, JWH-018, and JWH-073 increased drug-lever responding in monkeys discriminating Δ9-THC; the ED50 values were 0.044, 0.013, and 0.058 mg/kg, respectively and the duration of action was 4, 2, and 1 h, respectively. Rimonabant (0.32-3.2 mg/kg) produced surmountable antagonism of Δ9-THC, JWH-018, and JWH-073. Schild analyses and single-dose apparent affinity estimates yielded apparent pA2/pK(B) values of 6.65, 6.68, and 6.79 in the presence of Δ9-THC, JWH-018, and JWH-073, respectively. In Δ9-THC-treated monkeys discriminating rimonabant, the training drug increased responding on the rimonabant lever; the ED50 value of rimonabant was 0.20 mg/kg. Δ9-THC (1-10 mg/kg), JWH-018 (0.32-3.2 mg/kg), and JWH-073 (3.2-32 mg/kg) dose-dependently attenuated the rimonabant-discriminative stimulus (i.e., withdrawal). These results suggest that Δ9-THC, JWH-018, and JWH-073 act through the same receptors to produce Δ9-THC-like subjective effects and attenuate Δ9-THC withdrawal. The relatively short duration of action of JWH-018 and JWH-073 might lead to more frequent use, which could strengthen habitual use by increasing the frequency of stimulus-outcome pairings. This coupled with the possible greater efficacy of JWH-018 at cannabinoid 1 receptors could be associated with greater dependence liability than Δ9-THC.
Assuntos
Discriminação Psicológica/efeitos dos fármacos , Dronabinol/farmacologia , Alucinógenos/farmacologia , Drogas Ilícitas/farmacologia , Indóis/farmacologia , Naftalenos/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Interpretação Estatística de Dados , Aprendizagem por Discriminação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Dronabinol/antagonistas & inibidores , Feminino , Indóis/antagonistas & inibidores , Macaca mulatta , Masculino , Abuso de Maconha/tratamento farmacológico , Abuso de Maconha/psicologia , Naftalenos/antagonistas & inibidores , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Rimonabanto , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Síndrome de Abstinência a Substâncias/psicologiaRESUMO
Our previous study showed that single injection of methamphetamine decreases social interaction (SI) in a dose-dependent manner that was further affected by stressful environment conditions. The aim of this study was to examine the effect of methamphetamine and its interaction with gonadal hormones on SI. Adult male and female rats were gonadectomized and assigned to testosterone-treated and oil-treated groups in male rats and estradiol-treated and oil-treated groups in female rats, respectively. Hormones were administered 30 min before each habituation in the open field. All four hormonal groups were further divided to control (without injection), saline (1 ml/kg saline injection), and methamphetamine (1 mg/kg) groups. Injections were applied 30 min before the SI test. The total duration and the total number of SI and nonsocial behavioral patterns were assessed. This study showed that an acute methamphetamine administration in a dose of 1 mg/kg decreased different types of SI in both sexes. In contrast, the same dose of methamphetamine increased locomotion and rearing behavior in male and female rats. The frequency and/or duration of SI (especially mutual sniffing and allogrooming) was lower in adult female rats relative to gonadectomized male rats, but locomotion was increased in female relative to male rats regardless of the presence or absence of gonadal hormones. In conclusion, this study is novel especially because it examines SI in both sexes in relation to the presence or absence of gonadal hormones.
Assuntos
Comportamento Animal , Estimulantes do Sistema Nervoso Central/farmacologia , Relações Interpessoais , Metanfetamina/farmacologia , Animais , Avaliação Pré-Clínica de Medicamentos , Interações Medicamentosas , Estradiol/metabolismo , Estradiol/farmacologia , Feminino , Hormônios Gonadais/metabolismo , Hormônios Gonadais/farmacologia , Gônadas/cirurgia , Locomoção , Masculino , Modelos Animais , Atividade Motora , Ratos , Ratos Wistar , Fatores Sexuais , Testosterona/metabolismo , Testosterona/farmacologiaRESUMO
Methamphetamine (MA) is one of the most frequently used illicit drugs worldwide and also one of the most common drugs abused by pregnant women. Repeated administration of psychostimulants induces behavioral sensitization in response to treatment of the same or related drugs in rodents. The effect of prenatal MA exposure on sensitivity to drugs in adulthood is not yet fully determined. Because our most recent studies demonstrated that prenatal MA (5mg/kg) exposure makes adult rats more sensitive to acute injection of the same drug, we were interested whether the increased sensitivity corresponds with the increased drug-seeking behavior. The aim of the present study was to examine the effect of prenatal MA exposure on drug-seeking behavior of adult male rats tested in the conditioned place preference (CPP). The following psychostimulant drugs were used as a challenge in adulthood: MA (5mg/kg), amphetamine (5mg/kg) and cocaine (10mg/kg). All psychostimulant drugs induced increased drug-seeking behavior in adult male rats. However, while MA and amphetamine-induced increase in drug-seeking behavior did not differ based on the prenatal drug exposure, prenatally MA-exposed rats displayed tolerance effect to cocaine in adulthood. In addition, prenatally MA-exposed rats had decreased weight gain after administration of MA or amphetamine, while the weight of prenatally MA-exposed rats stayed unchanged after cocaine administration. Defecation was increased by all the drugs (MA, amphetamine and cocaine), while only amphetamine increased the tail temperature. In conclusion, our results did not confirm our hypothesis that prenatal MA exposure increases drug-seeking behavior in adulthood in the CPP test.
Assuntos
Metanfetamina/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Anfetamina/efeitos adversos , Análise de Variância , Animais , Peso Corporal/efeitos dos fármacos , Cocaína/efeitos adversos , Condicionamento Operante/efeitos dos fármacos , Modelos Animais de Doenças , Dopaminérgicos/efeitos adversos , Feminino , Masculino , Gravidez , Ratos , Ratos Wistar , Transtornos Relacionados ao Uso de Substâncias/etiologiaRESUMO
The effect of psychostimulants on social behavior still remains unclear. Therefore the aim of the present study was to assess the effect of low doses of methamphetamine (MA) on social interaction (SI) in adult male rats. Rats were tested in three environmental conditions: (1) dimly lit, familiar environment, (2) dimly lit, unfamiliar environment and (3) intensely lit, unfamiliar environment considered to be low, middle and high stress, respectively. In each condition different set of animals was used. Rats were always divided into five groups. Control (without injection), saline (with 1 ml/kg saline injection) and three MA groups (doses: 0.5, 1 and 1.5mg/kg). Injections were applied 30 min prior to testing. Always a pair of unfamiliar rats of the same treatment group was tested. Their behavior was video recorded for 5 min in an open field. Times spent by SI (following, climbing, genital investigation, etc.) and non-social behavior (locomotion, rearing) were analyzed using a two-way ANOVA (drug treatment x stress condition). Our data demonstrate that all doses of MA, reduced SI. In addition, the unfamiliarity of the arena increased exploratory behavior (locomotion and rearing) in all treatment groups, while the SI was affected by the environmental condition only in controls or saline-treated rats, but not in MA-treated groups. In conclusion, our data demonstrate that MA administration impairs SI in dose- and stress condition-specific manner, however, some of our results may be due to increase locomotion and rearing induced by MA.
Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Metanfetamina/farmacologia , Comportamento Social , Animais , Relação Dose-Resposta a Droga , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Wistar , Estresse Psicológico/psicologiaRESUMO
The aim of our study was to examine the effect of prenatal methamphetamine (MA) exposure and cross-fostering on cognitive functions of adult male rats tested in Morris water maze (MWM). Rat mothers were exposed daily to injection of MA (5mg/kg) or saline for 9 weeks: prior to impregnation, throughout gestation and lactation periods. Females without any injections were used as an absolute control. On postnatal day 1, pups were cross-fostered so that each mother raised 4 pups of her own and 8 pups from the mothers with the other two treatments. Four types of tests were used: (1) Place navigation test (Learning), (2) Probe test (Probe), (3) Retention memory test (Memory) and (4) Visible platform task. Our results demonstrate that the prenatal exposure to MA does not impact learning and memory, while postnatal exposure to MA shows impairments in cognition. In the test of learning, all animals fostered to MA-treated dams had longer latencies, bigger search error and used lower spatial strategies than the animals fostered to control or saline-treated mother, regardless of prenatal exposure. Regardless of postnatal exposure, the animals prenatally exposed to saline swam faster in all the tests than the animals prenatally exposed to MA and controls, respectively. This study indicates that postnatal but not prenatal exposure to MA affects learning in adult male rats. However, it is still not clear whether these impairments are due to a direct effect of MA on neuronal structure or due to an indirect effect of MA mediated by impaired maternal care.
Assuntos
Estimulantes do Sistema Nervoso Central/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Cuidados no Lar de Adoção/psicologia , Metanfetamina/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Análise de Variância , Animais , Animais Recém-Nascidos , Comportamento Animal , Distribuição de Qui-Quadrado , Feminino , Masculino , Comportamento Materno/fisiologia , Aprendizagem em Labirinto/efeitos dos fármacos , Testes Neuropsicológicos , Gravidez , Ratos , Tempo de Reação/fisiologia , Retenção Psicológica/efeitos dos fármacos , Retenção Psicológica/fisiologia , Natação/psicologia , Fatores de TempoRESUMO
The aim of the present study was to determine effects of methamphetamine (MA) exposure and cross-fostering on thermal nociceptive thresholds in different estrous phases in adult female rats. Rat mothers were exposed daily to injection of MA (5 mg/kg) or saline for 9 weeks: prior to impregnation, throughout gestation and lactation periods. Dams without any injections were used as an absolute control. On postnatal day 1, pups were cross-fostered so that each mother raised four pups of her own and eight pups from the mothers with the other two treatments. Offspring females were tested in adulthood (85-90 days) for thermal nociception as latency [s] of withdrawal reaction of forelimbs, hind limbs, and tail. Our results showed that prenatal MA exposure did not affect the nociception in adulthood, while postnatal MA exposure (i.e., MA administration to lactating mothers) had pro-nociceptive effects. The effect of postnatal MA exposure was apparent in both, fore- and hind limbs, while the latency to tail withdrawal reaction was the same among the groups. In addition, the pro-nociceptive effect of postnatal MA exposure did not depend on estrous cycle. This study indicates that postnatal but not prenatal exposure to MA affects nociception in adult female rats. However, it is still not clear whether the pro-nociceptive effect of postnatal MA exposure is linked to direct action of MA on neuronal organization, or to indirect action of MA mediated by impaired maternal care.
Assuntos
Animais Recém-Nascidos/fisiologia , Metanfetamina/toxicidade , Limiar da Dor/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Simpatomiméticos/toxicidade , Fatores Etários , Animais , Diestro/efeitos dos fármacos , Feminino , Injeções Subcutâneas , Neurônios/efeitos dos fármacos , Gravidez , Proestro/efeitos dos fármacos , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Sensação Térmica/efeitos dos fármacosRESUMO
Methamphetamine is a commonly abused psychostimulant that causes addiction and is often abused by pregnant women. Acute or chronic administration of methamphetamine elevates the levels of the extracellular monoamine neurotransmitters, such as dopamine. The aim of the present study was to show whether prenatal exposure to methamphetamine (5mg/kg, entire gestation) or saline in Wistar rats induces changes in dopamine levels and its metabolites in the nucleus accumbens, and in behavior (locomotor activity, rearing, and immobility) after the administration of a challenge dose of methamphetamine (1mg/kg) or saline in male offspring. We found that adult offspring prenatally exposed to methamphetamine had higher basal levels of dopamine (about 288%), dihydroxyphenylacetic acid (about 67%) and homovanillic acid (about 74%) in nucleus accumbens. An increased basal level of dopamine corresponds to lower basal immobility in offspring prenatally exposed to methamphetamine. The acute injection of methamphetamine in adulthood increased the level of dopamine in the nucleus accumbens, which is related to an increase of locomotion and rearing (exploration). In addition, prenatally methamphetamine-exposed rats showed higher response to the challenge dose of methamphetamine, when compared to prenatally saline-exposed rats. In conclusion, rats exposed to methamphetamine in utero have shown changes in the mesolimbic dopaminergic system and were more sensitive to the administration of the acute dose of methamphetamine in adulthood.
Assuntos
Comportamento Animal/efeitos dos fármacos , Dopamina/metabolismo , Metanfetamina/toxicidade , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Inibidores da Captação Adrenérgica/toxicidade , Animais , Comportamento Animal/fisiologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Feminino , Ácido Homovanílico/metabolismo , Masculino , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/fisiopatologia , Núcleo Accumbens/crescimento & desenvolvimento , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Tempo , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/crescimento & desenvolvimento , Área Tegmentar Ventral/fisiopatologiaRESUMO
Cocoons of Theridiosoma gemmosum consist of two main parts, the egg sac case and the stalk. The inner space of the egg sac case is filled with nonsticky flocculent silk. Measuring 600-800 nm in diameter, the flocculent threads are never made up of bundles of longitudinally oriented nanofibrils. The egg case wall consists of a lower layer of highly ordered threads and an upper layer of cover silk. The lower, permanently white layer consists of threads in a mesh-like arrangement, the thicker threads being 4-6 microm and the thinner threads being 2-3 microm in diameter. Each thread is a bundle of parallel nanofibrils, with a diameter between 150 and 300 nm. The silk secretions of these fibers, emitted from spigots, are processed by legs. The upper layer of the egg case is applied to the threads of the lower layer by direct rubbing against its surface, i.e. without the use of legs. In the lower and middle part of the egg case, the accumulated secretion forms a virtually compact encrustation, whereas in the upper, conically shaped, part of the egg case where it becomes the stalk, this secretion becomes substantially scarcer. The stalk is a continuation of the egg case, its proximal part made of fibers similar to those forming the inner layer of the egg case wall. The distal part of the stalk continues towards the suspension area either as a compact bundle of parallel fibers, or the stalk forks into two bundles of roughly the same thickness, which continue towards the suspension area separately. On the surface of objects onto which cocoons are attached, the secretion of the piriform glands acts as an adhesive sheet.