Measurement of Ionic F Concentration in the Plasma
F concentration in the plasma was determined by using
F-specific electrode (Elit-221, Akvilon, Russia) and AgCl3
reference electrode coupled to potentiometer I-500 (Akvilon,
Russia) as described elsewhere [17]. The system was previ-
ously calibrated with the standards of known F concentrations
buffered with TISAB II (pH 5.2). The samples of rat plasma
were prepared under the same conditions as the standards.