Insulin treatment, acute or chronic, does not alter the number of CHT proteins at the cell surface, their binding affinity or the maximal uptake of choline.

Choline uptake and HC-3 binding were assessed over a concentration range to determine kinetic parameters. Data were fit by Michaelis-Menten nonlinear regression and are expressed as mean ± SEM of 5 experiments (choline uptake) and 3 experiments (HC-3 binding). Units: Choline uptake Vmax = pmol / mg protein / 5 min, Km = μM; HC-3 binding Bmax = fmol / mg protein, KD = nM. ND–not determined.