Model to evaluate the toxic effect of drugs: vincristine effect in the mass of organs and in the distribution of radiopharmaceuticals in mice

There are evidences that the biodistribution of radiopharmaceuticals can be modified by some drugs. As chemotherapeutic drugs present important toxic effects, we studied the vincristine effect in the mass of organs and are tr ying to develop a model to evaluate the action of chemotherapeutic drug usi ng the biodistribution of radiopharmaceuticals. Vincristine was administere d (n = 15) into female Balb/c mice, the organs isolated and their mass dete rmined. To study the vincristine effect in the biodistribution of technetiu m-99m-dimercaptosuccinic acid (Tc-99m-DMSA) or technetium-99m-diethylenetri aminepentaacetic acid Tc-99m-DTPA), vincristine (0.03 mg) was administered in the animals (n = 15) in three doses. Tc-99m-DMSA or Tc-99m-DTPA was inje cted 1 h after the last dose. After 0.5 h, the animals were sacrificed and the percentage of radioactivity (%ATI) and the percentage of radioactivity per gram of tissue (%ATI/g) in each organ were calculated. The results have shown that the mass decreased significantly (Wilcoxon test, P < 0.05) in t hymus, spleen, ovary, uterus, kidneys, pancreas. The %ATI to Tc-99m-DMSA in creased in lung, pancreas, heart, thyroid, brain, and bone, and the %ATI/g increased in uterus, ovary, spleen, thymus, kidney, lung, liver, pancreas, heart, thyroid, brain and bone. To Tc-99m-DTPA, the %ATI increased in uteru s, ovary, spleen, thymus, kidney, lung, liver, stomach, heart and bone, and the %ATI/g increased in uterus, ovary, spleen, thymus, kidney, lung, liver , stomach, heart and bone. The results were statistically significant (Wilc oxon test). The results can be explained by the metabolization, therapeutic , toxicological or immunosupressive action of the vincristine. This model, probably, should be used to evaluate the toxic effect of various drugs. (C) 2001 Elsevier Science BN. Ali rights reserved.