[The electrophoretic pattern of gamma-glutamyl transferase in serum and its alteration by chylomicrons (author's transl)].

Using the sera from 20 patients with elevated gamma-glutamyl transferase activity (EC 2.3.2.2) due to intra- or posthepatic cholestasis, the enzyme was separated into four bands by cellulose acetate foil electrophoresis. The gamma-glutamyl transferase pattern permitted no differentiation between intra- or posthepatic cholestasis. Protein and lipid electrophoresis was performed simultaneously for each serum. It was found that a gamma-glutamyl transferase band, which appeared at the origin in 11 sera, was only observed in lipaemic sera containing chylomicrons. This band of gamma-glutamyl transferase does not, however, represent a true isoenzyme, because it results from a complex between chylomicrons and gamma-glutamyl transferase, which is separated with the chylomicrons, or is produced by the mixing of sera.