Fig. 10.

The incorporation of radioactivity into lipids in tissues of golden hamsters after [U-¹⁴C]leucine injection.

Golden hamsters were injected intraperitoneally with 2.5 μCi of [U-¹⁴C]leucine (Du Pont, Boston, MA, USA) diluted with Dulbecco’s phosphate-buffered saline (D-PBS). Three, 6, 9 and 24 h after injection, Harderian gland, liver, brain, and heart were obtained under anesthesia with sodium pentobarbital. They were kept overnight in 5 ml of chloroform/methanol (2:1, v/v) at room temperature and then lipids were extracted in the liquid phase. Five hundred micro liters of this fraction was evaporated under N₂ gas, and then dissolved in 2 ml of Clear-sol I (Nacalai Tesque, Kyoto). Radioactivity in the solution was measured with a liquid scintillation spectrometer (Tri-Carb 15000; Packard Instruments, Downers Grove, IL, USA).