Perspective Volume 1, Issue 2 pp 146—153

Figure 4. Aged thymocytes have increased resistance to spontaneous and dexamethasone-induced apoptosis. Spontaneous (A) and dexamethasone (dex)-induced (B) apoptosis at 0.5nM was assessed by flow cytometry. Graphs show the percentage of viable thymocytes defined as Annexin V^- 7AAD^- (top graphs)and those undergoing early apoptosis as Annexin V⁺ 7AAD^- (bottom graphs). Closed square/circle with dotted line symbolise young thymocytes cultured in media or with the addition of 0.5nM dex respectively. Whereas, open square/circle with solid line signify thymocytes from 18 month old mice cultured in media or with the addition of 0.5nM dex respectively. The data revealed that there is an age-associated increased resistance to spontaneous and dex-induced apoptosis with a higher percentage of viable thymocytes from older mice compared to younger mice and delayed kinetic of older thymocytes to initiate apoptosis. Data representative of four experiments. *P<0.05; **P<0.01.