Fig. 2. Glucose stimulation enhances membrane internalisation and increases endocytotic vesicle size in INS-1 cells. Experiments were performed with 2.6 mM Ca²⁺ in the patch-pipette and 0 mM Ca²⁺ in the bath. (A) The rate of membrane internalisation is increased when 10 mM glucose is present in the bath. (B) Glucose did not increase the frequency at which endocytotic events occurred. (C) Glucose increased the unitary capacitance of endocytotic steps, reflecting a significant increase in endocytotic vesicle size. *, P<0.05; ***, P<0.001.