3 results on '"OLIVEIRA, ELISABETH SPINELLI"'
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2. Implications of dealing with airborne substances and reactive oxygen species: what mammalian lungs, animals, and plants have to say?
- Author
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Oliveira, Elisabeth Spinelli, Hancock, John T., Hermes-Lima, Marcelo, Isola, Daniel A., Ochs, Matthias, Yu, Jerry, and Filho, Danilo Wilhem
- Subjects
Antioxidants -- Properties ,Antioxidants -- Influence ,Air pollution -- Influence ,Air pollution -- Control ,Free radicals (Chemistry) -- Influence ,Free radicals (Chemistry) -- Control ,Zoology and wildlife conservation - Abstract
A gas-exchange structure interacts with the environment and is constantly challenged by contaminants that may elicit defense responses, thus compromising its primary function. It is also exposed to high concentrations of [O.sub.2] that can generate reactive oxygen species (ROS). Revisiting the lung of mammals, an integrative picture emerges, indicating that this bronchi-alveolar structure deals with inflammation in a special way, which minimizes compromising the gas-exchange role. Depending on the challenge, pro-inflammatory or antiinflammatory responses are elicited by conserved molecules, such as surfactant proteins A and D. An even broader picture points to the participation of airway sensors, responsive to inflammatory mediators, in a loop linking the immunological and nervous systems and expanding the role played by respiratory organs in functions other than gas-exchange. A byproduct of exposure to high concentration of [O.sub.2] is the formation of superoxide ([O.sup.*-.sub.2]), hydrogen peroxide ([H.sub.2][O.sub.2]), hydroxyl radical (H[O.sup.*]), and other ROS, which are known to be toxic to different types of cells, including the lung epithelium. A balance between antioxidants and oxidants exists; in pulmonary epithelial cells high intracellular and extracellular levels of antioxidants are found. Antioxidant adaptations related to plant and animal life-styles involve a broad range of overlapping strategies based on well-conserved molecules. Glutathione (GSH) is an abundant and ubiquitous thiol-tripeptide antioxidant, also present in lungs, whose role in providing information on the intracellular redox state of animals and plants is well established. In these organisms, GSH influences gene expression associated with stress, maximizing defense responses. Several enzymatic antioxidants, such as glutathione peroxidase (GPx), glutathione reductase, glutathione S-transferase, and glucose 6-phosphate dehydrogenase participate in the redox system; in animals that are stress-tolerant GPx is a key element against oxidative assaults. Most importantly, alternative roles of ROS as signaling molecules have been found in all plants and animals. For example, alveolar macrophages produce [O.sup.*-.sub.2] that act as second messengers, in addition to having a bactericidal role. The nonradical ROS [H.sub.2][O.sub.2] signals inflammation in mammalian lungs, apoptosis in different animal tissues, and is also involved in stomatal closure, root development, gene expression, and defense responses of plants. Antioxidant adaptations in some water-breathing animals involve the excretion of [H.sub.2][O.sub.2] by diffusion through gas-exchange structures. The fine balance among a multitude of factors and cells makes the difference between damage and protection in animals and plants. Knowledge about the mechanisms and consequences of these molecular interactions is now starting to be integrated.
- Published
- 2007
3. Comparative Biochemistry a Physiology Part A: Molecular & Integrative Physiology
- Author
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Mendes, Lys A. Favaroni, Rocha, Pedro Luís Bernardo da, Ribeiro, Martim F.S., Perry, Steven F., and Oliveira, Elisabeth Spinelli
- Subjects
Spineless spine rats ,Neotropics ,Echimyidae ,Semi-arid ,Ingestive behavior ,Thrichomys apereoides ,Adaptation ,Punare ,Rodents ,Caatinga - Abstract
p. 327-332 Submitted by JURANDI DE SOUZA SILVA (jssufba@hotmail.com) on 2012-11-19T12:24:45Z No. of bitstreams: 1 CONFIG~1...-S1095643304001527-main-1.pdf: 126532 bytes, checksum: dfc5ee52bca4f56d140ec3cd76d4d693 (MD5) Made available in DSpace on 2012-11-19T12:24:45Z (GMT). No. of bitstreams: 1 CONFIG~1...-S1095643304001527-main-1.pdf: 126532 bytes, checksum: dfc5ee52bca4f56d140ec3cd76d4d693 (MD5) Previous issue date: 2004 Thrichomys apereoides is widely distributed in the Caatinga, a semi-arid region in Brazil, but is presumed to lack capabilities for water conservation. In the present study, we compared two populations of adult individuals living under different precipitation conditions (700 and 450 mm year 1). Animals from the less dry area were twice as heavy as those from the drier locality. Under ad libitum water regimen, there were differences between populations in relative food intake as well as in water intake and urine concentration, but not in normalized body mass water intake. Under short-term water deprivation, both populations presented similar body mass loss. Whereas individuals from the more arid locality maintained food consumption, urine volume and urine osmolality, Thrichomys from the less dry locality reduced food consumption and urine volume. The occurrence of anuria in 75% of animals from this population indicates that the limits of their ability to deal with water shortage had been reached. The morphological and physiological difference and the non-allometric similarities found between the two populations of T. apereoides fulfill the criteria for physiological adaptations to differences in annual rainfall. Our data challenge the hypothesis that the irregularity of annual rainfall in the Caatinga precludes the evolution of adaptations to this semi-arid climate.
- Published
- 2004
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