Tissue distribution of lohexol, non-ionic contrast media, in squirrel monkeys after an injection into subarachnoidal space of lumbar spinal cord-Investigation by whole body autoradiography-

Abstract

Tissue distribution, especially in brain, was investigated after an injection of ¹²⁵I-iohexol into the subarachnoidal space of the lumbar spinal cord in squirrel monkeys at a dose of 129 mg/kg. Fifteen minutes after administration, a high concentration of radioactivity was found in whole spinal cord, subarachnoidal cisterns, blood, kidney and urinary bladder, but penetration of radioactivity into cerebral cortex was not observed. Three hours after administration, a high concentration of radioactivity was still found in whole spinal cord and subarachnoidal cisterns, and, in addition, a local penetration of radioactivity into the cerebral cortex was clearly observed, howeven at the relatively lower concentration. Twentyfour hours after administration, almost all radioactivity was eliminated not only from cerebrum and upper cerebrospinal cord, but also from almost all of the tissues. It was also confirmed that ¹²⁵ I-iohexol was rapidly transferred from subarachnoidal space into systemic blood and predominantly eliminated into urine via kidney.