title: Induction of antibodies in rats to a rat carcinoembryonic antigen.
abstract: In a previous communication, carcinoembryonic antigen (CEA) of rat, which is an analogue to human CEA, was demonstrated in gastrointestinal adenocarcinomas induced in inbred Fischer rats by injection of 1,2-dimethylhydrazine. Antibodies detectable by enzyme immunoassay were elicited in Fischer rats by immunization with a perchloric acid extract of the CEA-containing rat tumor, RCA-1, incorporated into Freund's complete adjuvant. Specificity studies showed that activity of the rat antisera could be virtually abolished by inhibition with the tumor extract used at a concentration of 25 micrograms/ml. Inhibition by newborn rat tissues required extract at a concentration of 250 micrograms/ml. Extracts of normal adult tissues did not inhibit at these concentrations, but did inhibit at a concentration of 2,500 micrograms/ml. The results showed that rat CEA, though present in low concentration in normal adult rat tissue, is capable of eliciting an immune response in rats.
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology; D000818:Animals; D000912:Antibodies, Neoplasm / Q000096:biosynthesis*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D003110:Colonic Neoplasms / Q000276:immunology; D007114:Immunization; D007124:Immunoenzyme Techniques; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000912:Antibodies, Neoplasm; D002272:Carcinoembryonic Antigen