Fig. 4.

Rate of cholesterol synthesis in the brains of Lal^+/+ and Lal^−/− mice at two different ages. These rates were measured in vivo using [³H]water as described in Materials and Methods. They reflect the rate of incorporation of water into new sterols throughout the entire brain over the course of 1 h. Values represent the mean ± SEM of measurements in 3 Lal^+/+ (1 male /2 females) and 5 Lal^−/− (3 males /2 females) mice at 23 days, and in 6 Lal^+/+ (all females) and 6 Lal^−/− (all females) mice at 50 days. All mice were of the FVB/N strain. At neither age was the value for the Lal^−/− mice significantly different from that for the matching Lal^+/+ controls (p >0.05).