Biodistribution of [Lys40(Ahx-DTPA-111In)NH
]-exendin-4. (A) Treatment of Rip1Tag2 mice with the VEGFR2-inhibitor vatalanib induces a sharp decrease of [Lys40(Ahx-DTPA-111In)NH2]-exendin-4 uptake into the tumor tissue and kidneys. In particular, specific tumor uptake diminishes by more than 50% within the first 5 days of vatalanib treatment (**p < 0.01, *p < 0.05, Newman-Keuls post-test). (B) Pre-treatment of Rip1Tag2 mice with imatinib does not significantly affect the specific uptake of [Lys40(Ahx-DTPA-111In)NH2]-exendin-4 into the tumor tissue and organs.