ABSTRACT
This chapter shows that tin (Sn) clearance in cancer-prone strains is slow, with the lymphatic system apparently absorbing a portion, albeit small, of the absorbed tin released by other tissue. A small number of pregnant mice were incorporated in a separate study in order to determine whether tin passed the placental barrier. Adenocarcinoma tumor fragments from an A/KI tumor were subdermally trans-planted in eight male A/KI mice, 120 days of age, in the upper right thorax. In an elaborate time profile study of a noncancer-prone mouse strain and two cancer-prone strains orally provided with inorganic Sn, it has been shown that the transport mechanism and sites of accumulation vary significantly. Applying the extraction techniques developed with the calf thymus, two fractions have been isolated from the mouse thymus, which is believed are analogs of the calf thymic anticarcinogens. Mice with transplanted mammary tumors exposed to Sn in their drinking water show little label in the tumor or the lymphatic system.
