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Immediate action of l-2,3,5,6-tetrahydrophenylimido (2,1b) azothiazol (levamisole) on the phagocytosis of inert radiocolloidal particles

1977; Pergamon Press; Volume: 4; Issue: 3-4 Linguagem: Inglês

10.1016/0047-0740(77)90143-7

1878-2337

R. Bergoc, R.A. Caro, J.N. Feierstein, J.E. Ihlo, A.J. Olivarri, A.F. Rojas,

Immune Cell Function and Interaction

Previous works demonstrated that the phagocytosis of radiogold colloidal particles follows Michaelis-Menten kinetics and that the process can be visualized as a two-stage phenomenon, consisting in the adsorption of the colloidal particle on the reticuloendothelial cell's surface and its posterior engulfment. Each stage is accounted for by the specific rate constants k1 and k2, respectively. Heretofore it was only possible to determine Ks, defined here as k2k1 and the maximal rate of phagocytosis, Vm. In the present work we propose a relatively simple method for the determination of k1, which allows the calculation of k2 and the number of active adsorption “loci” per kg body, (R). The comparison of the kinetic data for the gelatine or polyvinylpyrrolidone protected radiogold colloids shows that the corresponding (R) values are not significantly different. Therefore, the differences between the respective Ks and Vm values should be attributed to changes of k1 and principally of k2.Our method and experimental results allow a deeper comprehension of the phenomenon of phagocytosis, which will be useful for the study of the influence of immunomodulating drugs on either stage of this process.