Quantitative and qualitative changes in production of excretions/secretions by Litomosoides carinii during development in the jird (Meriones unguiculatus).

Excretions and secretions (E-S) were collected from a series of developmental stages of Litomosoides carinii maintained in vitro. Measurement of the protein content of E-S obtained from each stage indicates that the rate of production of E-S varies enormously during development of the worm. E-S was iodinated using both Iodogen and the Bolton and Hunter Reagent and was also biosynthetically labelled by incubating worms in the presence of [35S]methionine and [3H]leucine. Attempts to biosynthetically label E-S of mature worms and microfilariae with [3H]glucose were unsuccessful. Examination of radio-isotope labelled E-S by SDS-PAGE revealed that some components were sex specific and that the differences in total E-S production during development were due to the existence of both stage-specific components and components whose rate of release varied during parasite maturation. Antigenic characterization of E-S, carried out by immunoprecipitation in combination with SDS-PAGE, indicated that E-S consists of immunogenic components, a molecule which is probably a non-immunogenic parasite product, and host albumin. The implications of these findings for the construction of diagnostic tests to detect products of human filarial parasites are discussed.