501684-93-1

To estimate the ability of NS 1738 to permeate the blood-brain barrier, rats are administered 10 mg/kg NS 1738 intraperitoneally. Peak brain concentrations are measured approximately 30 min after injection, and they amount to ~80 ng/mL (~200 nM) at this dose. The ratio between the amount of compound entering the brain and that in plasma is AUC_brain /AUC_plasma=0.50. The half-life in plasma is estimated to 42 min. Incubation of NS1738 with isolated liver microsomes in vitro indicates that approximately 60 and 75% of NS 1738 is metabolized via the cytochrome P450 system in mouse and rat, respectively, within 1 h. Adult rats administered NS 1738 at 10 and 30 mg/kg i.p. immediately following the initial exposure to a juvenile rat (T1) display significant decreases in the investigative duration of a subsequent exposure to the same juvenile (T2) 2 h later (T2/T1 ratio of 0.69±0.13 and 0.61±0.07, respectively)^[1].