RESUMEN
The paper describes an introductory characterization of antigenic stimulation of excretion-secretion products (ESP) of Gnathostoma binucleatum advanced third-stage larvae cultured in vitro and proteinases present in this products. Excretory and secretory proteins were obtained after 10 larvae were maintained in 5% CO(2) RPMI medium. The supernatant was collected each week for two months. The proteins were dialyzed, concentrated, and separated in 10% SDS-PAGE gels under reducing conditions and transferred to nitrocellulose paper for immunoblot analyses. G. binucleatum immunized mice serum was used to determine protein antigenicity. Four proteins of 40, 80, 120, and 208 kDa persisted for two months and three proteins, 80, 120, and 208 kDa were recognized for antibodies of mice. In SDS-PAGE gelatin substrate gels ESP resolved as two proteins with molecular weight of 80 and 208 kDa that were sensitive to a metalloproteinase inhibitor, and thus it may be inferred that they might be used for diagnosis of gnathostomiasis.