[Radiolabeling of a new agent for the study of colorectal tumors].
A new Monoclonal Antibody (AcMo) ior-C5, highly specific for the most part of colorectal adenocarcinomas has been developed. The AcMo was labeled with 99mTc by the Schwarz's direct method using molar ratios MAb: reductant of 1:1,000 and 1:2,000. The first molar ratio was the most adequate for the preparation of the radiopharmaceutical. A labeling yield greater than 95% was obtained. Several <<in vitro>> assays were carried out in order to evaluate the stability of the preparation, whose results reflected the presence of the stable complex 99mTc-IgG. The biodistribution patterns for both preparations were similar. The excreting organs behaved like normal. Nevertheless, a greater renal excretion was observed for the preparation of the molar ratio of 1:2.000, which could be due to the presence of low affinity sites observed in this preparation. They are vulnerable to the trans-chelation of the 99mTc toward cysteine or glutathione present in plasma and tissues.
Quesada Cepero
W
W
Departamento de Medicina Nuclear Instituto Nacional de Oncología y Radiobiología Calle 29 y E. Vedado C., Habana, Cuba.
Pimentel González
G
G
Oliva González
J
J
Pérez Tenorio
G
G
Aguiar Cabeza
E
E
Sánchez Monzón
I
I
Hernández Romero
O
O
Rebustillo Sierra
M
M
D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics; D001798:Blood Proteins / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D003545:Cysteine / Q000737:chemistry; D004355:Drug Stability; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry / Q000493:pharmacokinetics; D007668:Kidney / Q000378:metabolism; D008297:Male; D008623:Mercaptoethanol / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D010084:Oxidation-Reduction; D016719:Radioimmunodetection; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D019163:Reducing Agents / Q000494:pharmacology; D013667:Technetium / Q000493:pharmacokinetics; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D001798:Blood Proteins; D018796:Immunoconjugates; D019275:Radiopharmaceuticals; D019163:Reducing Agents; D008623:Mercaptoethanol; D013667:Technetium; D003545:Cysteine
Radiomarcaje de un nuevo agente para el estudio de tumores colorrectales.