RESUMEN
In this study, we present the translational modeling used in the discovery of AZD1979, a melanin-concentrating hormone receptor 1 (MCHr1) antagonist aimed for treatment of obesity. The model quantitatively connects the relevant biomarkers and thereby closes the scaling path from rodent to man, as well as from dose to effect level. The complexity of individual modeling steps depends on the quality and quantity of data as well as the prior information; from semimechanistic body-composition models to standard linear regression. Key predictions are obtained by standard forward simulation (e.g., predicting effect from exposure), as well as non-parametric input estimation (e.g., predicting energy intake from longitudinal body-weight data), across species. The work illustrates how modeling integrates data from several species, fills critical gaps between biomarkers, and supports experimental design and human dose-prediction. We believe this approach can be of general interest for translation in the obesity field, and might inspire translational reasoning more broadly.
Asunto(s)
Fármacos Antiobesidad/administración & dosificación , Azetidinas/administración & dosificación , Modelos Biológicos , Obesidad/tratamiento farmacológico , Oxadiazoles/administración & dosificación , Receptores de la Hormona Hipofisaria/antagonistas & inhibidores , Investigación Biomédica Traslacional , Animales , Fármacos Antiobesidad/farmacocinética , Fármacos Antiobesidad/farmacología , Fármacos Antiobesidad/uso terapéutico , Azetidinas/farmacocinética , Azetidinas/farmacología , Azetidinas/uso terapéutico , Biomarcadores/metabolismo , Peso Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Descubrimiento de Drogas , Ingestión de Energía/efectos de los fármacos , Femenino , Humanos , Masculino , Ratones , Obesidad/metabolismo , Oxadiazoles/farmacocinética , Oxadiazoles/farmacología , Oxadiazoles/uso terapéutico , Ratas , Receptores de la Hormona Hipofisaria/metabolismo , Proyectos de InvestigaciónRESUMEN
Orogastric gavage, while a common method for delivering experimental substances in mice, has been shown to induce stress. To minimize the associated stress with this procedure, sham gavage prior to the start of experiment is a common method for habiutating mice. We investigated whether handling and restraint could replace sham treatment in the acclimatization protocol. Mice were either undisturbed, hand-restrained for 10 s or sham-gavaged daily for six days prior to eight days of twice daily gavage. The results showed that repetitive restraint and gavage had no differences in body weight after eight days of treatment compared with the body weights at the start of treatment, whereas animals left undisturbed lost significant weight once treatment began. These data suggest that procedure refinement by replacing sham treatment with hand restraint is sufficient to acclimatize mice to the stress associated with gavage.
Asunto(s)
Nutrición Enteral/efectos adversos , Habituación Psicofisiológica , Ratones/fisiología , Pérdida de Peso , Animales , Femenino , Ratones Endogámicos C57BL , Ratones Obesos , Estrés FisiológicoRESUMEN
Accumulating evidence indicates that an animal's response to a drug can be profoundly affected by early environmental influences. The brain opioid and dopamine systems may play a critical role in these effects, since various types of stress and drugs of abuse promote alterations in these brain systems. To study this further, we investigated long-term behavioural and neurochemical effects of repeated maternal separation in male Wistar rats. The pups were separated in litters daily from their dams for either 15 min (MS15) or 360 min (MS360) from postnatal days 1-21. Analysis of the kappa- and delta-opioid, dopamine D(1)- and D(2)-like receptors with receptor autoradiography revealed long-term neurochemical changes in several brain areas. D(1)-like receptor binding was affected in the hippocampus and D(2)-like receptor binding in the ventral tegmental area and the periaqueductal gray, whereas minor changes were seen in opioid receptor density after maternal separation. At 10-13 weeks of age, MS15 rats had a lower ethanol intake whereas, the MS360 rats consumed more 8% ethanol solution compared with MS15 and animal facility-reared rats. Ethanol consumption altered kappa-receptor density in several brain areas, for example the amygdala, substantia nigra and the periaqueductal gray. D(1)-like receptor binding was affected in distinct brain areas, including the nucleus accumbens, where also delta-opioid receptor density was changed in addition to the frontal cortex. Ethanol-induced changes were observed in D(2)-like receptor density in the ventral tegmental area in MS360, and in the ventral tegmental area and frontal-parietal cortex in animal facility-reared rats. These findings show that early experiences can induce long-lasting changes in especially brain dopamine receptor density and that ethanol consumption induces alterations in opioid and dopamine receptor density in distinct brain areas. It is also suggested that changes induced by repeated MS15 may provide protection against high voluntary ethanol intake.
Asunto(s)
Benzazepinas/análogos & derivados , Encéfalo/metabolismo , Privación Materna , Receptores Dopaminérgicos/metabolismo , Receptores Opioides/metabolismo , Tiempo , Consumo de Bebidas Alcohólicas , Alcoholismo , Animales , Animales Recién Nacidos , Autorradiografía , Benzazepinas/farmacocinética , Sitios de Unión , Peso Corporal , Encéfalo/efectos de los fármacos , Química Encefálica , Corticosterona/sangre , Antagonistas de Dopamina/farmacocinética , Etanol/administración & dosificación , Femenino , Masculino , Antagonistas de Narcóticos , Embarazo , Ratas , Restricción Física/métodos , Estrés Fisiológico/sangre , Estrés Fisiológico/fisiopatologíaRESUMEN
The occurrence of endogenous opioids and their receptors in rat achilles tendon was analyzed by immunohistochemistry (IHC), radioimmunoassay (RIA), and in vitro binding assays. The investigation focused on four enkephalins, dynorphin B, and nociceptin/orphanin FQ. Nerve fibers immunoreactive to all enkephalins (Met-enkephalin, Leu-enkephalin, Met-enkephalin-Arg-Gly-Lys, Met-enkephalin-Arg-Phe) were consistently found in the loose connective tissue and the paratenon, whereas dynorphin B and nociceptin/orphanin FQ could not be detected. The majority of enkephalin-positive nerve fibers exhibited varicosities predominantly seen in blood vessel walls. Measurable levels of Met-enkephalin-Arg-Phe and nociceptin/orphanin FQ were found in tendon tissue using RIA, whereas dynorphin B could not be detected. In addition to the endogenous opioids identified, delta-opioid receptors on nerve fibers were also detected by IHC. Binding assays to characterize the opioid binding sites showed that they were specific and saturable for [3H]-naloxone (Kd 7.01 +/- 0.98 nM; Bmax 23.52 +/- 2.23 fmol/mg protein). Our study demonstrates the occurrence of an opioid system in rat achilles tendon, which may be assumed to be present also in other connective tissues of the locomotor apparatus. This system may prove to be a useful target for pharmacological therapy in painful and inflammatory conditions by new drugs acting selectively in the periphery.
Asunto(s)
Tendón Calcáneo/metabolismo , Encefalinas/metabolismo , Receptores Opioides/metabolismo , Animales , Técnica del Anticuerpo Fluorescente , Masculino , Radioinmunoensayo , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-DawleyRESUMEN
Animals exposed to short periods of handling during the critical period of development, i.e., the first 21 days of life in rats, show attenuated neuroendocrine responses to stress in adult life. We have previously reported long-term changes in brain dynorphin (DYN) peptide levels in male Sprague-Dawley rats after neonatal handling. The purpose of this study was to investigate whether neonatal handling, 15-min individual separation from the mother during postnatal days 1-21, can induce long-term changes in DYNB, Met-enkephalin Arg(6)Phe(7) (MEAP) and nociceptin/orphanin FQ (N/OFQ) immunoreactive (ir) levels in female Sprague-Dawley rats. The peptides were measured in brain and pituitary gland 2 months after the handling procedure. The results reveal that handled (H) rats had increased ir levels of N/OFQ, DYNB and MEAP in the periaqueductal gray (PAG) as compared to nonhandled (NH) controls. Furthermore, H rats had decreased ir levels of DYNB in the frontal cortex and in the amygdala. In contrast to previous findings in male rats, DYNB levels were unaffected in areas related to the hypothalamo-pituitary-adrenal (HPA)-axis. The results indicate that a manipulation early in life can induce persistent neurochemical changes in the N/OFQ and opioid peptide system in female Sprague-Dawley rats.
Asunto(s)
Animales Recién Nacidos/fisiología , Manejo Psicológico , Péptidos Opioides/metabolismo , Animales , Química Encefálica/fisiología , Cromatografía por Intercambio Iónico , Dinorfinas/metabolismo , Emociones/fisiología , Encefalina Metionina/análogos & derivados , Encefalina Metionina/metabolismo , Femenino , Embarazo , Ratas , Ratas Sprague-Dawley , NociceptinaRESUMEN
In order to investigate the involvement of the opioid and nociceptin/orphanin FQ (N/OFQ) system in alcohol drinking behaviour, N/OFQ and the opioid peptides dynorphin B (DYNB) and Met-enkephalin-Arg(6) Phe(7) (MEAP) were examined in the alcohol-preferring C57BL/6J mice. Basal peptide levels were compared in the brain and the pituitary gland with basal levels in the alcohol-avoiding DBA/2J mice. Furthermore, the effects of chronic alcohol self-administration on peptides were studied in the C57BL/6J mice. Compared to the DBA/2J mice, C57BL/6J mice had low immunoreactive (ir) levels of DYNB and MEAP in the nucleus accumbens, the hippocampus, and the substantia nigra, low ir-DYNB levels in the striatum and low ir-MEAP levels in the frontal cortex. Higher ir-DYNB levels in the pituitary gland and in the periaqueductal gray (PAG) and higher ir-N/OFQ levels in the frontal cortex and in the hippocampus were detected in C57BL/6J mice compared to the DBA/2J mice. After 4 weeks of voluntary alcohol consumption, only minor changes in steady-state peptide levels were identified. However, 5 days after the alcohol-drinking period, lower levels of all peptides were detected in the ventral tegmental area and ir-DYNB levels were also lower in the amygdala and in the substantia nigra. Twenty-one days after cessation of alcohol self-administration, the opioid peptides in alcohol-consuming C57BL/6J mice were lower in the PAG, the N/OFQ was lower in the frontal cortex and DYNB was higher in the amygdala and substantia nigra as compared to control C57BL/6J mice. This study demonstrates strain differences between C57BL/6J mice and DBA/2J mice that could contribute to divergent drug-taking behaviour, and it also demonstrates time- and structure-specific changes in neuropeptide levels after alcohol self-administration in the C57BL/6J mice.
Asunto(s)
Trastornos del Sistema Nervioso Inducidos por Alcohol/metabolismo , Química Encefálica/fisiología , Encéfalo/efectos de los fármacos , Dinorfinas/efectos de los fármacos , Encefalina Metionina/análogos & derivados , Encefalinas/efectos de los fármacos , Etanol/farmacología , Péptidos Opioides/efectos de los fármacos , Consumo de Bebidas Alcohólicas/efectos adversos , Trastornos del Sistema Nervioso Inducidos por Alcohol/fisiopatología , Animales , Encéfalo/metabolismo , Esquema de Medicación , Dinorfinas/metabolismo , Endorfinas/metabolismo , Encefalina Metionina/metabolismo , Encefalinas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL/metabolismo , Ratones Endogámicos DBA/metabolismo , Péptidos Opioides/metabolismo , Hipófisis/efectos de los fármacos , Hipófisis/metabolismo , Autoadministración/efectos adversos , NociceptinaRESUMEN
Recently, we have shown that rats repeatedly treated with ethanol and/or cocaine have decreased kappa-opioid receptor mRNA levels in the mesolimbic system. The aim of the present study was to investigate the short- and long-term effects of repeated ethanol administration on opioid peptide concentrations in brain tissue of male Sprague-Dawley rats. Dynorphin B (1-13) (Dyn B) and Met-enkephalinArg(6)Phe(7) (MEAP), endogenous ligands to kappa- and delta-opioid receptors, respectively, were measured using radioimmunoassays. The rats were given either ethanol [intraperitoneal (ip), twice daily, 2 g/kg bw/dose] or saline for 13 consecutive days. Thirty minutes after the last ethanol dose on Day 13, the Dyn B tissue concentration was significantly decreased in the cingulate cortex. The MEAP tissue concentration was decreased in the hippocampus 5 days after the last ethanol injection as compared to saline-treated controls. Furthermore, the Dyn B and the MEAP concentrations were increased in the periaqueductal grey area (PAG) at this time point. Of particular interest were the significant increases in Dyn B tissue concentrations found in the nucleus accumbens (NAcc) at 30 min and at 21 days after the last ethanol dose. The results suggest that repeated ethanol administration induces both short- and long-term changes in the tissue concentrations of opioids in certain brain regions associated with motivation and reward.
Asunto(s)
Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Dinorfinas/metabolismo , Endorfinas/metabolismo , Encefalina Metionina/análogos & derivados , Encefalina Metionina/metabolismo , Etanol/administración & dosificación , Animales , Química Encefálica , Dinorfinas/análisis , Endorfinas/análisis , Encefalina Metionina/análisis , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Cinética , Masculino , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Sustancia Gris Periacueductal/efectos de los fármacos , Sustancia Gris Periacueductal/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
The effects of neonatal handling on the opioid dynorphin peptides in the brain and pituitary gland of Sprague-Dawley rats were investigated. Ten weeks after the neonatal handling, handled rats had higher tissue levels of dynorphin A and B in the hypothalamus, pituitary gland and striatum and slightly higher dynorphin B levels in the hippocampus, medulla oblongata and midbrain as compared with non-handled controls. The results indicate a persistent upregulation of the dynorphin system in certain brain areas after neonatal handling, which could contribute to the behavioural changes in these rats observed later in life. Observation in the open field and the elevated plus-maze tests confirmed behavioural effects of neonatal handling, i.e. showing that handled rats exhibit attenuated fearfulness in novel environments as compared with non-handled rats.