ELECTRICAL CAPACITANCE METHOD APPLIED TO THE STUDY OF ACUTE EDEMAS

The aim of this study is to show that electrical capacitance can be used to determine the presence and time evolution of an acute edema in biological tissue. Measurements were done using a LCR meter, model HP LCR-815B, which measured the electrical capacitance between the electrodes localized on the rat skin across an edema induced by an inflammatory process. The technique was undertaken in rats, which received an injection of physiologic serum or carrageenin. The electrical capacitance was measured each 15min. Results for the physiologic serum group showed that there was an increment on the electrical capacitance with the rise of the water content and ion concentrations in the region between electrodes. Subsequently, capacitance decreased because of the absorption by the organism of the injected serum. Likewise, for rats with a carrageenin injection occurred first an increase in the electrical capacitance values, followed by a capacitance decrease accompanying the inflammation reduction. It was also studied the effect on the electrical capacitance when an anesthetic was injected into the rats. On the basis of our results it is possible to conclude that electrical capacitance measurements may be an adequate method to determinate the edema evolution in vivo.