[The phase I study of 99mTc-MAG3 injection, a dynamic renal imaging agent--evaluation of its safety and biodistribution in normal volunteers].

The phase I study of 99mTc-mercaptoacetylglycylglycylglycine (99mTc-MAG3) injection, which was developed as a radiopharmaceutical for dynamic renal scintigraphy, was performed in three normal volunteers. After intravenous administration of 370 MBq of 99mTc-MAG3 injection, its safety and biodistribution were evaluated. Neither adverse reaction nor abnormal clinical laboratory findings due to 99mTc-MAG3 administration were recognized. Immediately after injection, 99mTc-MAG3 was rapidly accumulated to the kidney and excreted to urine. The liver, gallbladder and intestine were visualized in the whole body images, but each of the percent injected dose in these organs was less than 2%. Excellent renal scintigrams and renograms with high kidney-to-background ratios were obtained. The estimated absorption doses from 99mTc-MAG3 injection were lower than those from 123I-ortho iodo hippurate (123I-OIH) and 99mTc-diethylene triamine penta-acetic acid (99mTc-DTPA). The results suggest that 99mTc-MAG3 injection is useful to evaluate renal functions because of the pharmacokinetic property suitable for renal dynamic scintigraphy.