Figure 6.

Endocytosis of leptin in CHO and RBE4 cell lines. A) Binding and endocytosis of ¹²⁵I-leptin in CHO and RBE4 cells overexpressing ObRa and ObR860 after incubation at 37°C for 30 min. Both ObRa and ObR860 induced a significant (P<0.01) increase in residual cell surface binding and endocytosis of ¹²⁵I-leptin. B) Endocytosis of Alexa-568 leptin in RBE4 cells overexpressing ObR860. Alexa-568 leptin (red) was effectively internalized into cells expressing ObR860 (green) after incubation at 37°C for 20 min. Dynasore almost completely abolished intracellular fluorescence of leptin, whereas nystatin had no apparent effects. C) Endocytosis of ¹²⁵I-leptin in RBE4 cells overexpressing ObR860 after treatment with different inhibitors. ¹²⁵I-leptin endocytosis was effectively inhibited by chlorpromazine and Dynasore, whereas nystatin had no effect. *P < 0.05; ***P < 0.005.