Autoradiogram demonstrating proteolytic stability of ³H labelled peptides in liver microsomes and organ homogenates.

³H-D3 was incubated with kidney, brain and liver homogenate for 0, 10, 30, 60, 240 min and 1, 2 days at 37°C and developed on TLC plates. For liver microsomes, the incubation time was 0, 10, 30, 60 and 120 min. Slight difference in Rf values of ³H-D3 in liver homogenate might be due to incompletely homogenized liver tissues, which was not observed after incubation with liver microsomes. (Two autoradiograms of liver homogenate were presented in one image and separated through a dashed line.) No obvious proteolytic degradation of D3 can be observed in all the organ homogenates with up to two days’ incubation.