AUTORADIOGRAPHIC DISTRIBUTION OF C-14-LABELED "3H-IMIDAZO[4,5-F]QUINOLINE-2-AMINES IN MICE

  • 1 January 1985
    • journal article
    • research article
    • Vol. 45  (3) , 1351-1356
Abstract
The highly mutagenic heterocyclic amines, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), are formed during heating of protein-rich foods. In order to gain information about the distribution and fate of IQ and MeIQ in vivo, a whole-body autoradiographic study of i.v.-injected 14C-labeled IQ and MeIQ was performed in male NMRI, pregnant NMRI and female C3H mice. IQ and MeIQ showed similar distribution patterns. At short survival times, the autoradiograms were characterized by an accumulation of radioactivity in metabolic and excretory organs (liver, kidney, bile, urine, gastric and intestinal contents, salivary glands, nasal mucosa and Harder''s gland), as well as in lymphomyeloid tissues (bone marrow, thymus, spleen and lymph nodes) and in endocrine and reproductive tissues (adrenal, medulla, pancreatic islets, thyroid, hypophysis, testis, epididymis, seminal vesicles, ampulla and prostate). The liver and kidney cortex were identified as sites of retention of nonextractable radioactivity. IQ and MeIQ showed a strong affinity for melanin. IQ and MeIQ passed the placenta, but no radioactivity was retained in fetal tissues. The results pinpoint the liver as a site of IQ- and MeIQ-mediated toxicity. Future studies of IQ and MeIQ may be guided by and clarify the role of other tissue localizations in the toxicity of IQ and MeIQ. [The neoplastic effect of these compounds was outlined.].