Fig. 12.

The Akt inhibitor, Akt Inhibitor VIII (Akti VIII), blocks the biological activity of SP-A on PC liposome uptake (A) and type II cell secretion (B). A: type II cells plated on Transwell membranes were incubated without Akti VIII (No Akti VIII) or with Akti VIII (10 μM) for 15 min with or without cAMP (0.1 mM) for 1 h. ³H-DPPC-labeled liposomes (45 μg PC/ml) were added without (Liposomes) or with SP-A at 5 μg/ml (Liposomes + SP-A) for 2 h. The cells were harvested with trypsin. Data are means ± SE of duplicate or triplicate dishes in 3–6 experiments. None, no cAMP; a, significant difference from Liposomes alone, no additions; b, significant difference from Liposomes + SP-A, None (no cAMP); c, significant difference from no Akti VIII. P < 0.05; n = 3–6. B: type II cells were incubated with [³H]choline overnight to label PC. Cells were washed and incubated without or with 1 mM ATP. Akti VIII (10 μM) and SP-A (0.2 μg/ml) were added at 30 and 15 min, respectively, before the addition of ATP. Secretion was measured over 1 h. Data are means ± SE of duplicate or triplicate samples from 3 experiments. *Significant difference from ATP; **significant difference from ATP + SP-A, no Akti VIII. P < 0.05; n = 3.