Data/hora: 10/06/2024 10:26:07

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | Determination of macromolecular exchange and PO2 in the microcirculation: a simple system for in vivo fluorescence and phosphorescence videomicroscopy
Autores: | Torres,L.N.; Torres Filho,I.P.
Data: | 2001-01-01
Ano: | 2001
Palavras-chave: | Oxygen; Permeability; Microcirculation; Rat mesentery; Intravital microscopy; Phorphyrin.
Resumo: | We have developed a system with two epi-illumination sources, a DC-regulated lamp for transillumination and mechanical switches for rapid shift of illumination and detection of defined areas (250-750 µm²) by fluorescence and phosphorescence videomicroscopy. The system permits investigation of standard microvascular parameters, vascular permeability as well as intra- and extravascular PO2 by phosphorescence quenching of Pd-meso-tetra (4-carboxyphenyl) porphine (PORPH). A Pechan prism was used to position a defined region over the photomultiplier and TV camera. In order to validate the system for in vivo use, in vitro tests were performed with probes at concentrations that can be found in microvascular studies. Extensive in vitro evaluations were performed by filling glass capillaries with solutions of various concentrations of FITC-dextran (diluted in blood and in saline) mixed with different amounts of PORPH. Fluorescence intensity and phosphorescence decay were determined for each mixture. FITC-dextran solutions without PORPH and PORPH solutions without FITC-dextran were used as references. Phosphorescence decay curves were relatively unaffected by the presence of FITC-dextran at all concentrations tested (0.1 µg/ml to 5 mg/ml). Likewise, fluorescence determinations were performed in the presence of PORPH (0.05 to 0.5 mg/ml). The system was successfully used to study macromolecular extravasation and PO2 in the rat mesentery circulation under controlled conditions and during ischemia-reperfusion.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000100017
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2001000100017
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.34 n.1 2001
Fonte: | info:eu-repo/semantics/openAccess