Leptin activates phosphoryolations of STAT3, Akt, and ERK1/2 in NP cells.

<p>After 1-day serum deprivation, leptin (10 ng/ml) was added into the serum-free medium of NP cells for 5 min, 15 min and 30 min, and then the protein amouts of phosphorylated forms of Akt (p- Akt) (<b>A</b>), ERK1/2 (p- ERK1/2) (<b>B</b>) or STAT3 (p- STAT3) (<b>C</b>) were detected with western blotting analysis. GAPDH was also detected for a loading control.