The distribution of radioiodine-labeled N-isopropyl-p-iodoamphetamine in permanently ischemic brain of the Mongolian gerbil.

In a study of the distribution of N-isopropyl-p-131I-iodoamphetamine (IMP) in the permanently ischemic brain of 35 mongolian gerbils, the right common carotid artery was ligated under ether anesthesia. After given time intervals, 1.35 MBq (50 microCi) of IMP was injected into 17 gerbils which had severe neurological symptoms, and into 3 normal gerbils for controls. One minute there after each gerbil was sacrificed and brain autoradiography was performed. The activity of IMP in various parts of the brain was calculated from each autoradiogram. Low perfusion areas were observed in the right cerebral hemisphere and the brain stem (5-25% of normal value) from the first minute up to 24 h after ligation. In addition, low perfusion areas were also observed in the left cerebral hemisphere (40-60% of normal value) which represented a remote effect. These results suggest the usefulness of IMP for demonstrating cerebral ischemia and diaschisis.