The localization of 111In activity in the
tumor and draining lymph nodes of the H-4-II-E ACI rat
hepatoma was investigated following the injection of 111In-chloride. In this
tumor model, the
tumors metastasize to the regional lymph nodes in male rats only. The following experiments were performed: (a) biodistribution of 111In; (b) correlation of 111In uptake with [3H]
thymidine; (c)
gamma camera imaging; (d) autoradiography; (e)
iron competition and (f) binding of 131I-transferrin to H-4-II-E cells.
Tumor-to-muscle ratios of 111In in males were 4.9:1 in the primary
tumor and 9.1:1 in the metastatic lymph nodes 24 h post injection. In the
lymph node metastases in the males, a significant correlation between 111In uptake and [3H]
thymidine was observed (r = 0.737) suggesting that 111In uptake in the
metastases is related to cellular proliferation. No such correlation was observed in either primary
tumors (both male and female) or in the draining lymph nodes of the females. Metastatic lymph nodes in males could be detected in
gamma camera images while draining nodes in females could not be delineated. Injection of
ferric citrate prior to 111In administration resulted in a significant reduction of 111In uptake in the liver, spleen and
tumor and increased the amount of activity recovered from the kidney. Measurements of the binding of 131I-labeled rat
transferrin to H-4-II-E cells in vitro suggest that these cells display
transferrin receptors.