Table 2. Biodistribution of ^99mTc-1 in B16/F1 Melanoma-Bearing C57 Mice^a.

tissue	0.5 h	2 h	4 h	24 h	2 h NDP
Percentage Injected Dose/Gram (% ID/g)
tumor	9.64 ± 1.52	9.62 ± 1.53	12.15 ± 2.36	3.62 ± 1.10	1.12 ± 0.01*b
brain	0.15 ± 0.01	0.02 ± 0.01	0.02 ± 0.02	0.02 ± 0.01	0.02 ± 0.01
blood	2.66 ± 0.84	0.50 ± 0.14	0.06 ± 0.02	0.61 ± 0.46	0.03 ± 0.01
heart	1.56 ± 0.13	0.23 ± 0.04	0.10 ± 0.06	0.07 ± 0.03	0.17 ± 0.01
lung	3.85 ± 0.40	0.64 ± 0.15	0.34 ± 0.11	0.29 ± 0.12	0.48 ± 0.06
liver	1.41 ± 0.13	0.74 ± 0.08	0.86 ± 0.08	0.31 ± 0.08	0.57 ± 0.05
skin	3.07 ± 1.85	0.52 ± 0.40	0.32 ± 0.13	0.48 ± 0.24	0.29 ± 0.18
spleen	1.34 ± 0.15	0.32 ± 0.05	0.35 ± 0.05	0.18 ± 0.06	0.22 ± 0.06
stomach	1.83 ± 0.20	0.62 ± 0.17	0.77 ± 0.21	0.32 ± 0.16	0.62 ± 0.23
kidneys	30.5 ± 5.18	28.73 ± 3.40	28.70 ± 5.22	8.12 ± 2.34	13.67 ± 2.54*b
muscle	0.25 ± 0.02	0.04 ± 0.03	0.02 ± 0.01	0.05 ± 0.02	0.05 ± 0.07
pancreas	0.68 ± 0.28	0.11 ± 0.01	0.04 ± 0.02	0.04 ± 0.01	0.08 ± 0.01
bone	0.93 ± 0.45	0.19 ± 0.06	0.05 ± 0.01	0.42 ± 0.28	0.16 ± 0.09
Percentage Injected Dose (% ID)
intestines	1.71 ± 0.21	1.11 ± 0.60	1.59 ± 0.41	0.63 ± 0.19	0.76 ± 0.23
urine	53.37 ± 4.23	68.46 ± 9.28	83.96 ± 0.88	84.33 ± 3.37	90.95 ± 0.59
Uptake Ratio of Tumor/Normal Tissue
tumor/blood	3.62	19.24	202.50	5.93	37.33
tumor/kidneys	0.32	0.33	0.42	0.45	0.08
tumor/lung	2.50	15.03	35.74	12.48	2.33
tumor/liver	6.84	13.00	14.13	11.68	1.96
tumor/muscle	38.56	240.50	607.50	72.40	22.40

^aThe data are presented as percent injected dose/gram or as percent injected dose (mean ± SD, n = 4).

^b(∗) p < 0.05 for determining the significance of differences in tumor and kidney uptake between ^99mTc-1 with or without NDP-MSH peptide blockade at 2 h postinjection.