Fig. 2.

In vivo biodistribution of the four exendin variants after 4 h A without and B with block. BALB/c nude mice with subcutaneous INS-1 tumours were injected with 20 pmol of the corresponding compound. For the blocking condition, a 100x excess of either unlabelled exendin-4 (for exendin-4 and exendin-4-Pen groups) or unlabelled exendin(9-39) (for exendin(9-39) and exendin (9-39)-Pen groups) was administered together with the labelled compound. C Tumour uptake of all conjugates. Differences in tumour uptake were tested separately for each timepoint (1 h and 4 h) with a one-way ANOVA with post hoc Tukey’s correction. At 1 h, all groups significantly differed from each other in tumour uptake (p < 0.000001), except exendin-4 vs. exendin-4-Pen (p = 0.3). The same holds for the 4 h timepoint, where p < 0.0001 for all comparisons except for exendin-4 vs. exendin-4-Pen (p = 0.07). D Tumour/kidney ratios