Fig. 4.

Dose-dependent biodistribution of [³H]-PGN administered intravenously or intraperitoneally. (A) Mice were administered 40,000 CPM of [³H]-PGN intravenously and biodistribution to organs and tissues measured at 1 h, 4 h, 8 h, and 24 h postinjection. Welch’s ANOVA comparing time-point groups, excluding control: Brain P = 0.9236; Spleen P = 0.9972; Liver P = 0.4364; Kidney P = 0.0842; Heart P = 0.6337; Lung P = 0.1320; Fat P = 0.2897; Duodenum P = 0.1497; Ileum P = 0.8240; Colon P = 0.9038. (B) Mice were administered 400,000 CPM of [³H]-PGN intravenously (two injections of 200,000 cpm) 30 min apart, or 400,000 CPM of [³H]-PGN by gavage. Organs were harvested at 1 h after the first injection, or 4 h after gavage. Scintillation counting was performed on the dissolved, decolored organs. (C) Biodistribution of [³H]-PGN administered intraperitoneally. Mice were injected intraperitoneally with 400,000 CPM of [³H]-PGN and scintillation counting performed on the dissolved, decolored organs harvested at 2 h and 6 h postgavage. Data are normalized as CPM values per g tissue weight. Pairwise comparison with control performed using the Mann–Whitney U test. *P ≤ 0.05; **P ≤ 0.005. Pairwise comparison with between time-points performed using the Mann–Whitney U test, Brain P = 0.0159; Spleen P = 0.8413; Liver P = 0.8413; Kidney P = 0.0079; Heart P = 0.7222; Lung P = 0.5952; Fat P = 0.0317; Duodenum P = 0.0159; Ileum P = 0.6905; Colon P = 0.8413. (D) [³H]-PGN detected in brain regions following administration by gavage. Schematic is a sagittal view of the mouse brain showing the average relative proportion of [³H]-PGN detected in each brain region. Right panel shows the [³H]-PGN measured in each region in CPM/g. Each data point represents the indicated brain region pooled from 5 mice. “Central brain areas” include the thalamus, hypothalamus and midbrain. Pairwise comparison of different regions to olfactory bulb performed using the Mann–Whitney U test *P ≤ 0.05.