[Experimental study on liver accumulation of N-isopropyl-p-iodoamphetamine]

In order to clarify the mechanism of N-isopropyl-p-iodoamphetamine (IMP) liver accumulations, liver dynamic study by the portal injection of 123I-IMP and liver microautoradiography by 125I-IMP were performed using 5, 2 male rats, respectively. The initial uptake of 123I-IMP in the liver was very high and thereafter 123I-IMP showed relatively rapid wash-out (count ratio of lung to liver at 10 min after the injection was 0.12, 0.15). On the other hand, the addition of 5 mg, 8 mg ketamine hydrochloride decreased the initial 123I-IMP liver uptake and its lung accumulation was noted immediately after the injection (count ratio of lung to liver at 10 min was 0.20). Microautoradiography of the liver using 125I-IMP showed grain density in the central vein and sinusoids, but not in the liver parenchymal cell. These results suggest that non-specific amine receptor (binding site) may exist in the endothelial cell in the central vein, although the number of experimental rats in this series was small for conclusion.