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This paper reviews the rapidly changing global demands for animal-source foods, examines the agri-food systems behind these changes, and discusses the potential responses required by public-sector Veterinary Services to meet these new demands.
Les auteurs examinent la demande mondiale en denrées alimentaires d'origine animale et ses évolutions extrêmement rapides, ainsi que les systèmes agroalimentaires qui sous-tendent ces changements ; ils abordent ensuite les différentes mesures que les Services vétérinaires du secteur public devraient envisager afin de répondre à ces nouvelles exigences.
Los autores examinan la demanda mundial de alimentos de origen animal, que cambia con gran rapidez, describen los sistemas agroalimentarios que se encuentran detrás de esta evolución y consideran las posibles respuestas de los Servicios Veterinarios del sector público que se requieren para atender esta nueva demanda.
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Ração Animal , Gado , Animais , Serviços de Saúde , Setor PúblicoRESUMO
Earlier reviews to discover research on interventions for children after neglect have concluded little was available, despite the well-documented prevalence and harmful effects of neglect on children. We revisited this question through a systematic literature review to discover the state of research on interventions for children who have experienced neglect. We searched MEDLINE, PsycINFO, ERIC, Sociological Abstracts and EMBASE for studies published between 2003 and 2021. Studies were included if neglect could be distinguished, and child outcomes reported. Eight reports describing six studies about six interventions were identified. These studies differed in interventions, age-groups, definitions of neglect, and outcomes. Four studies reported positive child outcomes though with varying degree of quality. More research is needed to inform a coherent theory of change following neglect. There remains an urgent need for research on interventions to help children recover from neglect.
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Small farmers produce most food in low- and middle-income countries and most small farmers rely on directly or indirectly working equids (WE). The lack of methods and metrics for assessing the role of WE hampers realisation of WE contributions. Based on literature review and a survey of WE welfare experts, we propose a framework for optimising WE potential based on two axes of sustainable development goals (SDGs) and value chains. WE contribute especially to earning and sparing income (largely in food production) (SDG 1), but also have roles in accessing health and hygiene services and products (SDG 3 and 5), providing edible products (SDG 2), and benefiting women (SDG 6), with lesser contributions to other SDGs, notably climate action (SDG 13). Experts identified barriers to appropriate appreciation of WE contributions, in order to target actions to overcome them. They found WE are neglected because they belong to farmers who are themselves neglected; because information on WE is inadequate; and, because the unique nature and roles of WE means systems, policies, investors, markets and service providers struggle to cater for them. Harnessing WE to optimally contribute to sustainable development will require generating better evidence on their contributions to SDGs, ensuring better integration into ongoing efforts to attain SDGs, and building the WE capacity among development actors.
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Políticas , Desenvolvimento Sustentável , Agricultura , Clima , Feminino , Humanos , Inquéritos e QuestionáriosRESUMO
Inbred tht strains Fischer 344 (F344) and Buffalo (BUF) differ in serveral physiological and behavioral measures. It was found that the activity of adrenomedullary and regional brain phenylethanolamine N-methyltransferase is at least four times higher in F344 rats than in BUF rats; these strain-dependent differences corresponded directly with the epinephrine content of the medulla-pons and hypothalamus. Conversely, alpha-adrenergic receptor density in brain regions containing phenylethanolamine N-methyltransferase is two to three times lower in F344 rats than in BUF rats; alpha-receptors in frontal cortex (a brain region lacking phenylethanolamine N-methyltransferase activity and epinephrine) are similar in both strains. These findings suggest that strain-dependent differences in alpha-receptors are regulated by inherited differences in presynaptic adrenergic neuronal function in different brain regions.
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Encéfalo/metabolismo , Epinefrina/fisiologia , Ratos Endogâmicos/metabolismo , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos/metabolismo , Medula Suprarrenal/enzimologia , Animais , Membrana Celular/metabolismo , Córtex Cerebral/enzimologia , Feminino , Hipotálamo/enzimologia , Bulbo/enzimologia , Feniletanolamina N-Metiltransferase/metabolismo , Ponte/enzimologia , Ratos , Especificidade da EspécieRESUMO
Physical inactivity is a global health risk that can be addressed through application of exercise training suitable for an individual's health and age. People's willingness to participate in physical activity is often limited by an initially poor physical capability and early onset of fatigue. One factor associated with muscle fatigue during intense contractions is an inexcitability of skeletal muscle cells, reflecting impaired transmembrane Na+/K+ exchange and membrane depolarization, which are regulated via the transmembranous protein Na+-K+-ATPase (NKA). This short review focuses on the plasticity of NKA in skeletal muscle in humans after periods of altered usage, exploring NKA upregulation with exercise training and downregulation with physical inactivity. In human skeletal muscle, the NKA content quantified by [3H]ouabain binding site content shows robust, yet tightly constrained, upregulation of 8-22% with physical training, across a broad range of exercise training types. Muscle NKA content in humans undergoes extensive downregulation with injury that involves substantial muscular inactivity. Surprisingly, however, no reduction in NKA content was found in the single study that investigated short-term disuse. Despite clear findings that exercise training and injury modulate NKA content, the adaptability of the individual NKA isoforms in muscle (α1-3 and ß1-3) and of the accessory and regulatory protein FXYD1 are surprisingly inconsistent across studies, for exercise training as well as for injury/disuse. Potential reasons for this are explored. Finally, we provide suggestions for future studies to provide greater understanding of NKA regulation during exercise training and inactivity in humans.
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Exercício Físico/fisiologia , Músculo Esquelético/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Humanos , Fadiga Muscular/fisiologia , Isoformas de Proteínas/metabolismoRESUMO
This paper discusses the sustainability of livestock systems, emphasising bidirectional relations with animal health. We review conventional and contrarian thinking on sustainability and argue that in the most common approaches to understanding sustainability, health aspects have been under-examined. Literature review reveals deep concerns over the sustainability of livestock systems; we recognise that interventions are required to shift to more sustainable trajectories, and explore approaches to prioritising in different systems, focusing on interventions that lead to better health. A previously proposed three-tiered categorisation of 'hot spots', 'cold spots' and 'worried well' animal health trajectories provides a mental model that, by taking into consideration the different animal health status, animal health risks, service response needs and key drivers in each system, can help identify and implement interventions. Combining sustainability concepts with animal health trajectories allows for a richer analysis, and we apply this to three case studies drawn from North Africa and the Middle East; Bangladesh; and the Eastern Cape of South Africa. We conclude that the quest for sustainability of livestock production systems from the perspective of human and animal health is elusive and difficult to reconcile with the massive anticipated growth in demand for livestock products, mainly in low- and middle-income countries, as well as the aspirations of poor livestock keepers for better lives. Nevertheless, improving the health of livestock can contribute to health sustainability both through reducing negative health impacts of livestock and increasing efficiency of production. However, the choice of the most appropriate options must be under-pinned by an understanding of agro-ecology, economy and values. We argue that a new pillar of One Health should be added to the three traditional sustainability pillars of economics, society and environment when addressing livestock systems.
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Criação de Animais Domésticos , Bem-Estar do Animal , Gado , Animais , Bangladesh , Conservação dos Recursos Naturais , Humanos , Oriente Médio , África do SulRESUMO
Foot-and-mouth disease (FMD) remains one of the most important livestock diseases of the world, given its highly infectious nature, its broad economic impacts on animal wellbeing and productivity, and its implications for successful access to domestic and export markets for livestock and products. The impacts of the disease vary markedly between developed and developing countries, and also within many developing countries. These differences in impact shape some markedly heterogeneous incentives for FMD control and eradication, which become of particular importance when setting priorities for poverty reduction in developing countries. Some consider that the benefits from FMD control accrue only to the better off in such societies and, as such, may not be a priority for investments targeted at poverty reduction. But is that view justified? Others see the control of FMD as a major development opportunity in a globalised environment. In this paper, Brian Perry and Karl Rich summarise the differential impacts of FMD and its control, and link these findings with the growing understanding of how the control of this globally important disease may contribute to the processes of pro-poor growth in certain countries of the developing world.
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Criação de Animais Domésticos/economia , Criação de Animais Domésticos/métodos , Febre Aftosa/prevenção & controle , Cooperação Internacional , Pobreza , Bem-Estar do Animal , Animais , Bovinos , Controle de Doenças Transmissíveis/economia , Controle de Doenças Transmissíveis/organização & administração , Efeitos Psicossociais da Doença , Países em Desenvolvimento , Febre Aftosa/economia , Febre Aftosa/epidemiologia , Prevenção PrimáriaRESUMO
The current system for the certification of internationally traded animal commodities can act as a barrier to developing countries accessing high-value international markets. In this Viewpoint article, Gavin Thomson and colleagues discuss the situation as it stands and identify inconsistencies with respect to the certification process. They suggest ways to address the lack of capacity for credible certification in some developing countries that will encourage market access for livestock commodities. They emphasise the role of mechanisms other than demonstrating that an area of production is free from a range of animal diseases, arguing that this could be of significant benefit to developing regions and countries, but that a reliable and independent system of certification based on international standards is essential.
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Certificação , Carne/economia , Carne/normas , Animais , Bovinos , Saúde Global , Cooperação InternacionalRESUMO
There is an increasing interest in determining the impact of vaccine technologies developed using public funding targeted at international development, and understanding the factors and ingredients which contribute to the success and impacts of such vaccines. This paper chronicles the development of a live vaccine against East Coast fever, a tick-borne disease of cattle caused by Theileria parva. The paper describes the technological innovation, commonly known as infection-and-treatment, which was developed some 40 years ago, explores the institutional settings in which the vaccine was developed and refined, and discusses the political dynamics of both during the decades from first development to field deployment and impacts. The paper also analyses the direct and indirect indicators of success of ITM and the many qualifiers of these, the impacts that the emerging technology has had, both in positive and negative terms, and maps the key contributors and milestones on the research-to-impact pathway.
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Inactivity negatively impacts on skeletal muscle function mainly through muscle atrophy. However, recent evidence suggests that the quality of individual muscle fibers is also altered. This study examined the effects of 23 days of unilateral lower limb suspension (ULLS) on specific force and sarcoplasmic reticulum (SR) Ca(2+) content in individual skinned muscle fibers. Muscle biopsies of the vastus lateralis were taken from six young healthy adults prior to and following ULLS. After disuse, the endogenous SR Ca(2+) content was â¼8% lower in type I fibers and maximal SR Ca(2+) capacity was lower in both type I and type II fibers (-11 and -5%, respectively). The specific force, measured in single skinned fibers from three subjects, decreased significantly after ULLS in type II fibers (-23%) but not in type I fibers (-9%). Western blot analyses showed no significant change in the amounts of myosin heavy chain (MHC) I and MHC IIa following the disuse, whereas the amounts of sarco(endo)plasmic reticulum Ca(2+)-ATPase 1 (SERCA1) and calsequestrin increased by â¼120 and â¼20%, respectively, and the amount of troponin I decreased by â¼21%. These findings suggest that the decline in force and power occurring with muscle disuse is likely to be exacerbated in part by reductions in maximum specific force in type II fibers, and in the amount of releasable SR Ca(2+) in both fiber types, the latter not being attributable to a reduced calsequestrin level. Furthermore, the â¼3-wk disuse in human elicits change in SR properties, in particular a more than twofold upregulation in SERCA1 density, before any fiber-type shift.
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Cálcio/metabolismo , Contração Isométrica , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Músculo Esquelético/fisiopatologia , Atrofia Muscular/fisiopatologia , Retículo Sarcoplasmático/metabolismo , Sinalização do Cálcio , Células Cultivadas , Feminino , Humanos , Masculino , Fibras Musculares de Contração Rápida/patologia , Fibras Musculares de Contração Lenta/patologia , Músculo Esquelético/patologia , Atrofia Muscular/patologia , Retículo Sarcoplasmático/patologia , Adulto JovemRESUMO
Phenylethanolamine N-methyltransferase (PNMT) is the enzyme that catalyzes the S-adenosyl-L-methionine-dependent methylation of (-)norepinephrine to (-)epinephrine in the adrenal medulla. Adrenal PNMT activity is markedly different in two highly inbred rat strains; enzyme activity in the F344 strain is more than fivefold greater than that in the Buf strain. Initial characterization of the enzyme in the two inbred strains reveals evidence for catalytic and structural differences, as reflected in dissimilar Km values for the cosubstrate (S-adenosyl-L-methionine) and prominent differences in thermal inactivation curves. To assess adrenal PNMT activity in an F344 X Buf pedigree, we employed a statistical procedure to test for one- and two-locus hypotheses in the presence of within-class correlations due to cage or litter effects. The PNMT data in the pedigree are best accounted for by segregation at a simple major locus superimposed upon a polygenic background; data obtained from the biochemical studies suggest that the major locus is a structural gene locus.
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Medula Suprarrenal/enzimologia , Feniletanolamina N-Metiltransferase/genética , Ratos Endogâmicos BUF/genética , Ratos Endogâmicos F344/genética , Ratos Endogâmicos/genética , Animais , Catecolaminas/análise , Cruzamentos Genéticos , Dopamina beta-Hidroxilase/análise , Feminino , Genes , Masculino , Ratos , Tirosina 3-Mono-Oxigenase/análiseRESUMO
Many societies are spoiled for choice when they purchase meat and other livestock products, and around the globe food choice has grown dramatically in the last two decades. What is more, besides the cost and obvious health concerns influencing commodity section, an increasing proportion of choices is made to contribute to the achievement of certain ideals, such as natural resource management, climate change mitigation, animal welfare concerns and personal lifestyle. At the same time, human health considerations are becoming more important for consumption choices as richer societies, and increasingly the urban poor in low- and middle-income countries, face an unprecedented epidemic of over-consumption and associated diet-related non-communicable diseases. Animal source foods are considered significant contributors to this trend. This paper reviews this complicated arena, and explores the range of considerations that influence consumers' preferences for meat and other animal source foods. This paper also argues that deeper drivers of consumption behaviour of many foods may act in opposition to the articulated preferences for choices around animal source food consumption. We review how the returns to different causes are being valued, how emerging metrics are helping to manage and influence consumption behaviours, and draw conclusions regarding options which influence food choice.
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Comportamento de Escolha , Comportamento do Consumidor/estatística & dados numéricos , Comportamento Alimentar/psicologia , Preferências Alimentares/psicologia , Carne/estatística & dados numéricos , Animais , HumanosRESUMO
We examined platelet serotonin2 [5-hydroxytryptamine2 (5-HT2)] receptor binding sites, whole blood serotonin (5-HT), and plasma norepinephrine (NE) in male autistic children and their first-degree relatives. Saturation studies utilizing 125I-spiroperidol labeled the 5-HT2 sites with an affinity of 224.6 +/- 84.4 pmol/L (Kd). No group differences, i.e., autistic (n = 12), siblings (n = 6), parents (n = 22), control (adult; n = 7: child; n = 10), were seen for either the Kd or the total number of sites (Bmax: 14.3 +/- 10.9 fmol/mg protein). No correlations were found in any group between binding parameters (Kd or Bmax) and whole blood 5-HT. For the parental group, inverse correlations were found between NE and Bmax (standing NE, rs = -0.67, n = 21, p = 0.001; supine NE, rs = -0.49, n = 22, p = 0.021). In the autistic group, no correlation was seen between plasma NE and Bmax. A correlation between the autistic boys' Bmax and their fathers' Bmax was observed (rs = 0.79, n = 11, p = 0.004). These findings suggest (1) circulating NE may be involved in heterologous regulation of 5-HT2 receptors in the platelet and (2) genetic (paternal-filial) factors may play a role in the expression of 5-HT2 binding sites in the platelet. These preliminary findings are discussed in relation to heterologous receptor regulation. The relationships between these findings and either the pathophysiology of autism or hyperserotonemia in autism are unknown.
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Transtorno Autístico/genética , Plaquetas/metabolismo , Receptores de Serotonina/genética , Adolescente , Transtorno Autístico/diagnóstico , Transtorno Autístico/psicologia , Criança , Pré-Escolar , Humanos , Radioisótopos do Iodo , Masculino , Ensaio Radioligante , Receptores de Serotonina/fisiologia , Espiperona/farmacocinéticaRESUMO
Dysregulation of serotonergic function has been associated with aggression in several studies involving children, adolescents, and adults. This study investigated the relationship of platelet serotonergic measures to conduct disorder type, severity of aggression, and social skills impairment. Standardized assessments of diagnosis, aggression, impulsivity, and social skills were obtained from 43 male adolescents (ages 13-17) incarcerated at an involuntary residential treatment facility for juvenile offenders. Blood samples were collected and assayed for whole blood serotonin (5-HT) and platelet [3H]-paroxetine-labeled 5-HT-transporter binding. Whole blood 5-HT was higher in adolescents with conduct disorder, childhood type than in subjects with conduct disorder, adolescent type. Whole blood 5-HT was positively correlated with violence rating of the current offense and total offense points, and staff ratings of social skills impairment. Our findings are consistent with a relationship between 5-HT dysregulation and aggressive behavior in incarcerated adolescent boys with conduct disorder, particularly of childhood onset.
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Comportamento do Adolescente , Plaquetas/metabolismo , Transtorno da Conduta/sangue , Serotonina/sangue , Adolescente , Adolescente Institucionalizado , Adulto , Idade de Início , Plaquetas/efeitos dos fármacos , Transtorno da Conduta/psicologia , Humanos , Masculino , Paroxetina , Escalas de Graduação Psiquiátrica , Receptores de Serotonina/efeitos dos fármacos , Receptores de Serotonina/metabolismo , Inibidores Seletivos de Recaptação de Serotonina , Comportamento Social , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/psicologiaRESUMO
The authors found significantly fewer total platelet alpha 2-adrenergic receptor binding sites in 13 nonmedicated patients with borderline personality disorder than in 11 patients with borderline personality disorder who were receiving low doses of benzodiazepines and 18 nonpsychiatric control subjects. The two patient groups showed comparable degrees of depression as assessed by the Hamilton Rating Scale for Depression. However, nonmedicated borderline patients were considerably more anxious than medicated patients, raising the possibility that lower alpha 2-adrenergic receptor binding in borderline personality disorder is related to anxiety.
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Plaquetas/análise , Transtorno da Personalidade Borderline/sangue , Receptores Adrenérgicos alfa/análise , Transtornos de Ansiedade/diagnóstico , Transtornos de Ansiedade/metabolismo , Transtornos de Ansiedade/psicologia , Benzodiazepinas/uso terapêutico , Plaquetas/metabolismo , Transtorno da Personalidade Borderline/tratamento farmacológico , Transtorno da Personalidade Borderline/psicologia , Transtorno Depressivo/complicações , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Diagnóstico Diferencial , Humanos , Escalas de Graduação Psiquiátrica , Receptores Adrenérgicos alfa/metabolismo , Ioimbina/metabolismoRESUMO
BACKGROUND: Allograft rejection is a cellular immunological/inflammatory response that is, in part, directed by potent proinflammatory mediators. This study was designed to test the hypothesis that leukotriene B4 (LTB4) may have a role in graft rejection and that LTB4 receptor antagonists may be clinically useful in the treatment of allograft rejection. METHODS: We evaluated the potent and selective LTB4 receptor antagonist CP-105696 in a murine heterotopic cardiac allograft model with oral dosing daily for 28 days or in an induction protocol (day -1 to day 3). RESULTS: At a dose of 50 mg/kg/day (28 days), B10.BR (H2k) allografts transplanted into C57Bl/6 (H2b) recipients were significantly protected, as reflected by the mean survival time versus control grafts (27+/-20 days [n=10] vs. 12+/-6 days [n=14]; P=0.0146). Using an induction protocol (day -1 to day 3), CP-105696 at 100 mg/kg/day significantly prolonged allograft survival (33+/-23 days [n=9]; P=0.0026), but CP-105696 at 10 mg/kg/day did not (18+/-16 days [n=8]; P=0.1433). Syngeneic grafts survived indefinitely (n=11). Immunohistological evaluation of allografts at rejection revealed a mononuclear cell infiltrate composed primarily of CD3+ and CD11b+ (Mac-1+) cells, which were infrequent in syngeneic grafts. Allografts from mice treated with CP-105696 at 50 or 100 mg/kg/day demonstrated a selective reduction in beta2-integrin (Mac-1) expression on monocytes/macrophages, as demonstrated by CD11b staining density compared with allograft controls. CONCLUSIONS: The results suggest that LTB4 or other potential ligands for LTB4 receptors may be important mediators of allograft rejection and support the clinical evaluation of LTB4 receptor antagonists in human organ transplantation.
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Benzopiranos/farmacologia , Ácidos Carboxílicos/farmacologia , Rejeição de Enxerto/prevenção & controle , Transplante de Coração/imunologia , Receptores do Leucotrieno B4/antagonistas & inibidores , Animais , Antígenos CD11/análise , Antígenos CD18/análise , Imunoglobulina G/sangue , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL , Receptores do Leucotrieno B4/fisiologia , Transplante HomólogoRESUMO
The purpose of the study was to characterize the differences in epidemiology (risks of infection, morbidity, mortality) and potential control of East Coast fever (ECF) between the selected strata. Evidence of Theileria parva infection was assessed by increased antibody levels as measured in an indirect ELISA test by the percent positivity (PP) of serum samples relative to a strong positive reference serum. A prospective cohort study was conducted in five purposively sampled agroecological zone (AEZ)-grazing system strata in Murang'a District, Kenya, between March 1995 and June 1996. The study strata were selected to represent the widest range of ECF risks in the district and included, zero-grazing and open-grazing farms in the Upper Midlands (UM) one and four AEZs and zero-grazing farms in the UM2 AEZ. In total, 225 calves from 188 smallholder farms were examined from birth to age six months. Calves were recruited into the study at birth and visited within the first two weeks of life and thereafter at biweekly intervals for up to 14 visits. Important differences were observed between the different AEZ-grazing strata. Seroconversion risks of T. parva were highest in the UM4-open grazing stratum. Antibody prevalence in adult cattle and ECF morbidity and mortality risks were also highest in this stratum. In the open-grazing strata, particularly in the lower elevation AEZ, UM4, there was stronger challenge and a greater impact of ECF. There is likely to be an expansion of smallholder dairy farming into this area so that it is likely to be the most important target production system for ECF control in the central highlands of Kenya.
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Indústria de Laticínios/estatística & dados numéricos , Theileria parva , Theileriose/epidemiologia , Animais , Bovinos , Demografia , Incidência , Quênia/epidemiologia , Morbidade , Theileriose/mortalidadeRESUMO
The effect of chronic total sleep deprivation (TSD) on the regulation of central noradrenergic receptors was evaluated. Rats were subjected to 10 days of TSD by the disk-over-water method. As in previous TSD studies, these rats showed greater increases in food intake and energy expenditure and greater eventual declines in waking body temperature than their yoked-control (TSC) rats. After sacrifice, alpha 1-, alpha 2-, and beta-adrenoceptors were determined in 11 brain regions using radioligand binding assays with [3H]prazosin, [3H]rauwolscine, and 125I-iodocyanopindolol, respectively. Adrenoceptor density and affinity values were significantly different among TSD, TSC, and normally caged control rat groups only for the cerebellum, which showed higher alpha 2-binding density concomitant with lower affinity and lower beta-binding density than cage control rats. Such changes are attributable to apparatus or stimulus effects common to TSD and TSC rats. Given the absence of firm evidence for a TSD-induced downregulation of central noradrenergic receptors, the present results offer no support for the hypothesis of Siegel and Rogawski that a major function of paradoxical sleep is to upregulate these receptors.
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Química Encefálica/fisiologia , Norepinefrina/fisiologia , Receptores Adrenérgicos/fisiologia , Privação do Sono/fisiologia , Animais , Eletrodos Implantados , Eletroencefalografia , Eletromiografia , Cinética , Masculino , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Sono REM/fisiologiaRESUMO
Rats subjected to chronic total sleep deprivation (TSD) by the disk-over-water method have shown very large, sustained rebounds in paradoxical sleep (PS) (also known as REM sleep). Other studies have indicated that cholinergic mechanisms are involved in the instigation and maintenance of PS. Hypothetically, the large PS rebounds could be mediated by an upregulation of cholinergic receptors during TSD. To evaluate this hypothesis, regional brain cholinergic receptors were compared in rats subjected to 10-day TSD by the disk-over-water method (TSD rats), yoked control (TSC) rats which received the same physical stimulation but with much smaller reductions in sleep, and home cage control (HCC) rats. L-[3H]nicotine and [3H]quinuclidinyl benzilate were used as specific cholinergic radioligands for nicotinic and muscarinic receptor binding assays, respectively. Nicotinic receptor binding was not significantly different among groups for any of the brain regions assayed, including frontal cortex, parietal cortex, thalamus, amygdala, hippocampus, anterior hypothalamus, posterior hypothalamus, caudate, limbic system (including septal area, olfactory tubercle, and nucleus accumbens), midbrain, pons, and medulla. Thus, there was no evidence that changes in nicotinic receptors mediate the PS rebounds. For muscarinic receptor binding, TSD rats differed significantly from control rats only in showing a higher binding affinity than TSC rats in the limbic system and a lower binding density than HCC rats in the hippocampus. On the other hand, significant differences in muscarinic receptor binding sites between rats selectively deprived of PS and their yoked controls were found only for the septal area.(ABSTRACT TRUNCATED AT 250 WORDS)
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Encéfalo/metabolismo , Receptores Colinérgicos/metabolismo , Privação do Sono/fisiologia , Sono REM/fisiologia , Animais , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Regulação para CimaRESUMO
In order to determine if chronic administration of cocaine produced long-lasting alterations in dopamine receptor binding, rats were treated with single daily injections of cocaine (0, 10, or 20 mg/kg) for 15 consecutive days and killed either 20 min or 2 weeks after the last injection. The density of D1 binding sites in frontal cortex was either unchanged (10 mg/kg) or slightly increased (20 mg/kg) 20 min after the last daily injection, but was decreased 2 weeks later. D1 sites in striatum were decreased both immediately and 2 weeks after the injection regimen. Decreases in D1 binding site density in nucleus accumbens were observed only immediately after the last injection. In contrast to these effects on D1 binding sites, D2 binding sites were decreased in striatum and frontal cortex and increased in the nucleus accumbens 20 min after repeated cocaine, but were unaffected 2 weeks after repeated cocaine. Computer-assisted analysis of the saturation isotherms revealed that chronic administration of cocaine did not affect the affinity (Kd) of the radioligands used to label D1 or D2 sites. These findings suggest that repeated administration of cocaine results in long-term decreases in D1 binding sites in striatum and frontal cortex and transient decreases in D2 binding sites. Furthermore, cocaine caused opposite, transient effects on D1 and D2 site density in nucleus accumbens.