ABSTRACT
Often, in pet birds, any stimulus to lay eggs is unwanted in order to reduce reproductive diseases and disorders. The objectives of this study were: to determine the time necessary to promote ovary involution after an eight hour photoperiod using laying Japanese quails (Coturnix coturnix japonica); to connect the ovarian radiographic measurements with egg production; and to compare these measurements with direct ovary data obtained at necropsy. Birds were separated into three groups: 12h/24d (control group - 12h photoperiod for 24 days), 8h/24d and 8h/36d (8h photoperiod for 24 and 36 days). After euthanasia, all cadavers were x-rayed to measure ovary length and height. Birds were necropsied to measure ovarian length and weight. Results: radiographic ovary length demonstrated strong and positive correlation (r=0.96) with direct ovary length of all three groups; laying quails showed higher ovary height (p=0.025) and length (p=0.009) than non-laying quails; eight hours of artificial light per day promotes ovary length (p=0.025) and weight (p=0.009) reduction. Conclusions: radiography can estimate the ovary measure and indicate posture; an eight hour photoperiod of 24 days is not enough to promote ovarian regression, while the use of reduced photoperiod for 36 days promotes significant ovary involution.(AU)
Em aves de estimação, geralmente se opta pela redução de estímulos para a postura de ovos visando reduzir a ocorrência de doenças e alterações reprodutivas. Os objetivos deste estudo foram: determinar o tempo necessário para a involução ovariana após um fotoperíodo de oito horas de iluminação usando codornas-japonesas (Coturnix coturnix japonica) na fase de postura; relacionar as medidas radiográficas com a postura de ovos; e comparar estas com as medidas diretas obtidas à necropsia. As aves foram divididas em três grupos: 12h/24d (controle - fotoperíodo de 12 horas por 24 dias), 08h/24d e 08h/36d (fotoperíodo de oito horas por 24 e 36 dias). Após a eutanásia, os cadáveres foram radiografados para mensuração do comprimento e da altura do ovário. Foi efetuada a necropsia para aferição das medidas e pesagem dos ovários. Os resultados mostraram que: o comprimento ovariano obtido por meio de imagem radiográfica apresentou forte correlação positiva (r=0,96) com o comprimento direto do ovário das aves dos três grupos; as aves em período de postura apresentaram maiores medidas de altura do ovário (P=0,025) e comprimentos ovarianos (P=0,009) do que as aves fora de postura; a restrição de luminosidade com oito horas diárias de luz artificial promoveu redução do comprimento ovariano (P=0,025) e da massa ovariana (P=0,009). Conclusões: a radiografia pode estimar a medida do ovário e indicar postura; um fotoperíodo de oito horas de luz por 24 dias não é satisfatório para obter uma regressão ovariana, enquanto 36 dias com o fotoperíodo reduzido promovem uma significativa redução ovariana.(AU)
Subject(s)
Animals , Female , Body Weights and Measures/veterinary , Coturnix/anatomy & histology , Ovary/anatomy & histology , Gonads/physiology , Photoperiod , Radiography/veterinaryABSTRACT
The pressure behavior of proteins may be summarized as a the pressure-induced disordering of their structures. This thermodynamic parameter has effects on proteins that are similar but not identical to those induced by temperature, the other thermodynamic parameter. Of particular importance are the intermolecular interactions that follow partial protein unfolding and that give rise to the formation of fibrils. Because some proteins do not form fibrils under pressure, these observations can be related to the shape of the stability diagram. Weak interactions which are differently affected by hydrostatic pressure or temperature play a determinant role in protein stability. Pressure acts on the 2°, 3° and 4° structures of proteins which are maintained by electrostatic and hydrophobic interactions and by hydrogen bonds. We present some typical examples of how pressure affects the tertiary structure of proteins (the case of prion proteins), induces unfolding (ataxin), is a convenient tool to study enzyme dissociation (enolase), and provides arguments to understand the role of the partial volume of an enzyme (butyrylcholinesterase). This approach may have important implications for the understanding of the basic mechanism of protein diseases and for the development of preventive and therapeutic measures.
Subject(s)
Humans , Hydrostatic Pressure , Protein Structure, Tertiary , Butyrylcholinesterase/chemistry , Nuclear Proteins , Nerve Tissue Proteins/chemistry , Phosphopyruvate Hydratase/chemistry , Prions/chemistry , Repressor Proteins , ThermodynamicsABSTRACT
O artigo não apresenta resumo.
ABSTRACT
O artigo não apresenta resumo.