Study on~(125)I Labelling and Blood-brain Barrier Counteracting of Calcineurin B

Calcineurin B(CNB) is labeled with 125 I by iodogen method. The labeling yield is up 85%,the specific activity is 740 GBq·g -1 and the radiochemical purity is 95.7%.The blood brain barrier counteracting of 125 I CNB is investigated in rats' brain. The results show that blood brain barrier can counteract intact CNB into brain, but can not counteract it's decomposed peptide into brain.