Figure 1.

Permeation of urocortin across the neonatal and adult BBB in the CD1 mice (n = 7/group). A, The Ki for urocortin was significantly higher in the neonate than in the adult group (P < 0.05). The Vi for urocortin was also significantly higher than that for albumin in the neonatal mice (P < 0.0001). In adults, neither urocortin nor albumin showed meaningful influx (nonsignificant Ki), and their Vi did not differ from each other. B, After correction of the vascular space by subtraction of the ¹³¹I-albumin brain to serum ratio, the permeation of ¹²⁵I-urocortin remained higher in the neonates than the adults (P < 0.05). C, The half-life of ¹²⁵I-urocortin was 4.4 times higher in the neonates (6.33 min) than adults (1.43 min).