Table 1. Tumor-to-organ ratios.

Tumor to organ Ratio	15 min	60 min	240 min	15 min blocking	60 min blocking
Blood	0.541±0.064	0.652±0.244	0.565±0.119	0.419±0.046	0.497±0.078
Heart	1.664±0.191	2.506±1.980	1.551±0.282	1.289±0.232	1.423±0.330
Lung	0.744±0.096	1.232±1.245	0.818±0.207	0.587±0.079	0.674±0.178
Spleen	1.258±0.142	1.585±1.122	1.095±0.240	1.007±0.143	1.152±0.117
Liver	1.248±0.138	1.813±1.095	1.239±0.223	0.907±0.121	1.226±0.232
Kidney	0.474±0.088	0.797±0.510	0.611±0.144	0.333±0.079	0.501±0.078
Muscle	2.529±0.310	4.111±2.444	2.781±0.599	1.884±0.463	2.623±0.264
Intestinum	1.299±0.301	1.396±0.546	0.859±0.492	1.145±0.069	0.864±0.226
Brain	7.736±1.066	17.60±9.740	17.19±5.018	6.631±1.725	9.71±4.034

Tumor-to-organ ratios were calculated from the organ distribution of ¹³¹I-CaIX-P1 in female Balb/c nu/nu mice carrying SKRC 52 tumors after 15 min (n = 8 animals), 60 min (n = 10 animals) and 240 min (n = 3 animals) circulation of the radioligand in the blood stream. For in vivo blocking, 100 µL unlabeled peptide at a concentration of 10⁻³ M was co-injected with the radioligand and tumor-to-organ ratios were calculated after 15 min (n = 3 animals) and 60 min (n = 3 animals) circulation in the blood stream.