8 research outputs found

    Illuminating the life of GPCRs

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    The investigation of biological systems highly depends on the possibilities that allow scientists to visualize and quantify biomolecules and their related activities in real-time and non-invasively. G-protein coupled receptors represent a family of very dynamic and highly regulated transmembrane proteins that are involved in various important physiological processes. Since their localization is not confined to the cell surface they have been a very attractive "moving target" and the understanding of their intracellular pathways as well as the identified protein-protein-interactions has had implications for therapeutic interventions. Recent and ongoing advances in both the establishment of a variety of labeling methods and the improvement of measuring and analyzing instrumentation, have made fluorescence techniques to an indispensable tool for GPCR imaging. The illumination of their complex life cycle, which includes receptor biosynthesis, membrane targeting, ligand binding, signaling, internalization, recycling and degradation, will provide new insights into the relationship between spatial receptor distribution and function. This review covers the existing technologies to track GPCRs in living cells. Fluorescent ligands, antibodies, auto-fluorescent proteins as well as the evolving technologies for chemical labeling with peptide- and protein-tags are described and their major applications concerning the GPCR life cycle are presented

    ExercĂ­cio fĂ­sico, receptores β-adrenĂ©rgicos e resposta vascular Physical exercise, β-adrenergic receptors, and vascular response

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    O exercício aeróbio promove efeitos benéficos na prevenção e tratamento de doenças como hipertensão arterial, aterosclerose, insuficiência venosa e doença arterial periférica. Os receptores &#946;-adrenérgicos estão presentes em várias células. No sistema cardiovascular, promovem inotropismo e cronotropismo positivo cardíaco e relaxamento vascular. Embora os efeitos do exercício tenham sido investigados em receptores cardíacos, estudos focados nos vasos são escassos e controversos. Esta revisão abordará os efeitos do exercício físico sobre os receptores &#946;-adrenérgicos vasculares em modelos animais e humanos e os mecanismos celulares envolvidos na resposta relaxante. Em geral, os estudos mostram resultantes conflitantes, onde observam diminuição, aumento ou nenhum efeito do exercício físico sobre a resposta relaxante. Assim, os efeitos do exercício na sensibilidade &#946;-adrenérgica vascular merecem maior atenção, e os resultados mostram que a área de fisiopatologia vascular é um campo aberto para a descoberta de novos compostos e avanços na prática clínica.<br>Aerobic exercise promotes beneficial effects on the prevention and treatment of diseases such as arterial hypertension, atherosclerosis, venous insufficiency, and peripheral arterial disease. &#946;-adrenergic receptors are present in a variety of cells. In the cardiovascular system, &#946;-adrenergic receptors promote positive inotropic and chronotropic response and vasorelaxation. Although the effect of exercise training has been largely studied in the cardiac tissue, studies focused on the vascular tissue are rare and controversial. This review examines the data from studies using animal and human models to determine the effect of physical exercise on the relaxing response mediated by &#946;-adrenergic receptors as well as the cellular mechanisms involved in this response. Studies have shown reduction, increase, or no effect of physical exercise on the relaxing response mediated by &#946;-adrenergic receptors. Thus, the effects of exercise on the vascular &#946;-adrenergic sensitivity should be more deeply investigated. Furthermore, the physiopathology of the vascular system is an open field for the discovery of new compounds and advances in the clinical practice
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