Figure 5.

The PI-3 K/Akt pathway is involved in the antiapoptotic affect of GH. A) Neurospheres were deposited for 48 h in slides with defined media without EGF and FGF2, and then treated with GH for 1 h. Phospho Akt and GAPDH immunoreactivities were determined by western blot. B) Densitometric evaluation of results presented in A. Phospho Akt levels are expressed as arbitrary densitometric units and normalized to GAPDH levels. C) Neurospheres growing in defined media were treated for 24 h with saline (Control), GH (500 ng/mL), rapamycin (20 nM), or GH + rapamycin. Four hours before the end of the treatment period cells were given a BrdU pulse (10 μM). Neurospheres were then dissociated and cells were collected by centrifugation onto coated cover slips, and BrdU was detected by immunocytochemistry. * = p <0.05 vs Control; ** = p <0.001 vs Control and GH. D) and E) Neurospheres were placed into culture plates containing defined media without EGF and FGF2, and 24 h later treated for 48 h with saline, GH, rapamycin or GH + rapamycin, [D)] or saline, GH, LY 294002 (10 μM) or GH + LY 294002, [E)]. * = p < 0.01 vs Control; ** = p <0.01 vs Control and p <0.001 vs GH; ° = p <0.01 vs GH. In D) and E) basal apoptosis, determined by growing the cells in the defined media (Control +E+ F), was significantly lower (p <0.01) than in the other groups. E = EGF; F = FGF2. Bars = mean + SEM of 3 experiments in triplicate.