67Ga uptake and heparan sulfate content of Ehrlich solid tumor in mice

The relationship between ⁶⁷Ga uptake and heparan sulfate (HS) content in Ehrlich solid tumor (EST) of mice was investigated, and the effect of cyanomethylamine, papain, streptozotocin, or bleomycin pretreatment on ⁶⁷Ga uptake in EST was studied. ⁶⁷Ga uptakes in EST and kidney were much higher than other tissues, and these tissues also contained large amounts of HS. ⁶⁷Ga uptakes and HS synthesis in the EST were inhibited by pretreatment with cyanomethylamine or papain (inhibitors of fibrosis). Parallel reductions of ⁶⁷Ga uptake and HS synthesis in EST were observed in EST transplanted into streptozotocin-induced diabetic mice. The weight of EST in the bleomycin-injected group was decreased to less than half of the control, but no effect was observed on ⁶⁷Ga uptake per gram of EST. These results suggest that ⁶⁷Ga uptake in the tumor and inflammatory lesions are related to the quantity of HS in these tissues, and the correlation between the uptake of ⁶⁷Ga and the rate of cellular proliferation is secondary.