[Pharmacokinetics of cadmium-109 in blood and brain structures of the rat]. / Farmacocinética del cadmio-109 en sangre y estructuras cerebrales de rata.

Pharmacokinetics of cadmium chloride (109Cd) in blood and cerebral structures in male Wistar rats is studied. Blood kinetics is obtained after intravenous administration of 20 microCi 109Cd; the element is distributed according to an open bicompartimental model with a high alpha deposition constant. The half-life of the alpha-phase is 0.043 hours and the half-life of the beta-phase is 5.54 hours. The kinetics of 109Cd in cerebral structures is calculated after injection of a total amount of 1 microCi in both lateral ventricles. Cadmium radionuclide in cerebral structures of the rat is rapidly fixed from the cerebral fluid, but released slowly. The structure of major accumulation is striatum and that of minor accumulation is cerebellum.

Pharmacokinetic study of vincamine teprosilate.

The results obtained by the authors in the pharmacokinetic study of vincamine teprosilate after oral and i.v. administration to young healthy volunteers and after oral administration to patients aged 68 to 84 years are presented. The description of the assay for each administration route is reported in the protocol. Plasma levels of vincamine teprosilate were assayed by reverse phase HPLC with spectrofluorimetric detection. The data obtained after i.v. administration made it possible to define the pharmacokinetic model and to estimate parameters. Concentration-time data were adapted to a biocompartmental open model with alpha value of 2.9080 and beta value 0.1047. In oral administration, the overlapping of the fast disposition phase and the absorption phase led to an apparent monocompartmental fit; in both young and aged volunteers, the absorption rate constants as well as the elimination rate constants were calculated. In both groups no significant differences in tmax values were found and no latency period was noticed . Cmax values were similar in both groups of patients; the lower distribution volume in aged volunteers compared to younger ones contributed to this finding. Differences in absorption rate constants in aged and young volunteers (0.53 h-1 and 0.73 h-1 respectively) are analysed. Vincamine teprosilate bioavailability after oral administration was found to be 20 +/- 5%. Possible vincamine teprosilate dose dependence kinetics are suggested.