Administration of LY 411575 at a dose of 5 mg/kg per day is sufficient to reduce Notch1 activation in vivo. C57BL/6 mice were fed Harlan-Teklad rodent chow formulated with LY 411575 to deliver 5 mg/kg per day for 3 months. (A) Progressive hair graying evident in GSI-fed (silver mouse, n = 5) but not control chow-fed (black mouse, n = 4) mice. (B) Bulk splenocytes were harvested from mice fed chow containing LY 411575 at the dose previously described for 3 months, and were cultured for 72 hours with or without αCD3ϵ stimulation. Whole-cell lysates were prepared, and Notch1^IC and GAPDH expression was detected by immunoblot. Data are representative of n = 4 (control) and n = 5 (GSI). (C) Graphic representation of band intensities from panel B. Expression of Notch1^IC was normalized to GAPDH expression.